Python django.template.engine.Engine 模块，get_default() 实例源码

def get_template_source(name, dirs=None):
    """Retrieves the template's source contents.

    :param name: Template's filename, as passed to the template loader.
    :param dirs: list of directories to optionally override the defaults.
    :return: tuple including file contents and file path.
    """
    loaders = []
    for loader in Engine.get_default().template_loaders:
        # The cached loader includes the actual loaders underneath
        if hasattr(loader, 'loaders'):
            loaders.extend(loader.loaders)
        else:
            loaders.append(loader)

    for loader in loaders:
        try:
            return loader.load_template_source(name, template_dirs=dirs)
        except TemplateDoesNotExist:
            pass

    raise TemplateDoesNotExist(name)

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")

        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                        'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")

        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")


        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that LogEntry, ContentType and the
        auth context processor are installed.
        """
        from django.contrib.contenttypes.models import ContentType

        if not ContentType._meta.installed:
            raise ImproperlyConfigured("Put 'django.contrib.contenttypes' in "
                                       "your INSTALLED_APPS setting in order to use the admin application.")

        default_template_engine = Engine.get_default()
        if not ('django.contrib.auth.context_processors.auth' in default_template_engine.context_processors or
                'django.core.context_processors.auth' in default_template_engine.context_processors):
            raise ImproperlyConfigured("Put 'django.contrib.auth.context_processors.auth' "
                                       "in your TEMPLATE_CONTEXT_PROCESSORS setting in order to use the admin application.")

def sample_template():
    template_string = """
    {% load djpt_limits %}
    {% djptlimit 'TimeLimit' total=3 %}
    {{ slow_rendering }}
    {% enddjptlimit %}
    """
    return Engine.get_default().from_string(template_string)

def get_context_data(self, **kwargs):
        tags = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for tag_name, tag_func in library.tags.items():
                    title, body, metadata = utils.parse_docstring(tag_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'tag', _('tag:') + tag_name)
                    if body:
                        body = utils.parse_rst(body, 'tag', _('tag:') + tag_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'tag', _('tag:') + tag_name)
                    tag_library = module_name.split('.')[-1]
                    tags.append({
                        'name': tag_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'tags': tags})
        return super(TemplateTagIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        filters = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for filter_name, filter_func in library.filters.items():
                    title, body, metadata = utils.parse_docstring(filter_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'filter', _('filter:') + filter_name)
                    if body:
                        body = utils.parse_rst(body, 'filter', _('filter:') + filter_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'filter', _('filter:') + filter_name)
                    tag_library = module_name.split('.')[-1]
                    filters.append({
                        'name': filter_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'filters': filters})
        return super(TemplateFilterIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': lambda: open(template_file).read() if os.path.exists(template_file) else '',
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that admin and contenttypes apps are
        installed, as well as the auth context processor.
        """
        if not apps.is_installed('django.contrib.admin'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.admin' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        if not apps.is_installed('django.contrib.contenttypes'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.contenttypes' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        try:
            default_template_engine = Engine.get_default()
        except Exception:
            # Skip this non-critical check:
            # 1. if the user has a non-trivial TEMPLATES setting and Django
            #    can't find a default template engine
            # 2. if anything goes wrong while loading template engines, in
            #    order to avoid raising an exception from a confusing location
            # Catching ImproperlyConfigured suffices for 1. but 2. requires
            # catching all exceptions.
            pass
        else:
            if ('django.contrib.auth.context_processors.auth'
                    not in default_template_engine.context_processors):
                raise ImproperlyConfigured(
                    "Enable 'django.contrib.auth.context_processors.auth' "
                    "in your TEMPLATES setting in order to use the admin "
                    "application.")

def get_context_data(self, **kwargs):
        tags = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for tag_name, tag_func in library.tags.items():
                    title, body, metadata = utils.parse_docstring(tag_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'tag', _('tag:') + tag_name)
                    if body:
                        body = utils.parse_rst(body, 'tag', _('tag:') + tag_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'tag', _('tag:') + tag_name)
                    tag_library = module_name.split('.')[-1]
                    tags.append({
                        'name': tag_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'tags': tags})
        return super(TemplateTagIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        filters = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for filter_name, filter_func in library.filters.items():
                    title, body, metadata = utils.parse_docstring(filter_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'filter', _('filter:') + filter_name)
                    if body:
                        body = utils.parse_rst(body, 'filter', _('filter:') + filter_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'filter', _('filter:') + filter_name)
                    tag_library = module_name.split('.')[-1]
                    filters.append({
                        'name': filter_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'filters': filters})
        return super(TemplateFilterIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': lambda: open(template_file).read() if os.path.exists(template_file) else '',
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def check_dependencies(**kwargs):
    """
    Check that the admin's dependencies are correctly installed.
    """
    errors = []
    # contrib.contenttypes must be installed.
    if not apps.is_installed('django.contrib.contenttypes'):
        missing_app = checks.Error(
            "'django.contrib.contenttypes' must be in INSTALLED_APPS in order "
            "to use the admin application.",
            id="admin.E401",
        )
        errors.append(missing_app)
    # The auth context processor must be installed if using the default
    # authentication backend.
    try:
        default_template_engine = Engine.get_default()
    except Exception:
        # Skip this non-critical check:
        # 1. if the user has a non-trivial TEMPLATES setting and Django
        #    can't find a default template engine
        # 2. if anything goes wrong while loading template engines, in
        #    order to avoid raising an exception from a confusing location
        # Catching ImproperlyConfigured suffices for 1. but 2. requires
        # catching all exceptions.
        pass
    else:
        if ('django.contrib.auth.context_processors.auth'
                not in default_template_engine.context_processors and
                'django.contrib.auth.backends.ModelBackend' in settings.AUTHENTICATION_BACKENDS):
            missing_template = checks.Error(
                "'django.contrib.auth.context_processors.auth' must be in "
                "TEMPLATES in order to use the admin application.",
                id="admin.E402"
            )
            errors.append(missing_template)
    return errors

def get_context_data(self, **kwargs):
        tags = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for tag_name, tag_func in library.tags.items():
                    title, body, metadata = utils.parse_docstring(tag_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'tag', _('tag:') + tag_name)
                    if body:
                        body = utils.parse_rst(body, 'tag', _('tag:') + tag_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'tag', _('tag:') + tag_name)
                    tag_library = module_name.split('.')[-1]
                    tags.append({
                        'name': tag_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'tags': tags})
        return super(TemplateTagIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        filters = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for filter_name, filter_func in library.filters.items():
                    title, body, metadata = utils.parse_docstring(filter_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'filter', _('filter:') + filter_name)
                    if body:
                        body = utils.parse_rst(body, 'filter', _('filter:') + filter_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'filter', _('filter:') + filter_name)
                    tag_library = module_name.split('.')[-1]
                    filters.append({
                        'name': filter_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'filters': filters})
        return super(TemplateFilterIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                if os.path.exists(template_file):
                    with open(template_file) as f:
                        template_contents = f.read()
                else:
                    template_contents = ''
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': template_contents,
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def check_dependencies(**kwargs):
    """
    Check that the admin's dependencies are correctly installed.
    """
    errors = []
    # contrib.contenttypes must be installed.
    if not apps.is_installed('django.contrib.contenttypes'):
        missing_app = checks.Error(
            "'django.contrib.contenttypes' must be in INSTALLED_APPS in order "
            "to use the admin application.",
            id="admin.E401",
        )
        errors.append(missing_app)
    # The auth context processor must be installed if using the default
    # authentication backend.
    try:
        default_template_engine = Engine.get_default()
    except Exception:
        # Skip this non-critical check:
        # 1. if the user has a non-trivial TEMPLATES setting and Django
        #    can't find a default template engine
        # 2. if anything goes wrong while loading template engines, in
        #    order to avoid raising an exception from a confusing location
        # Catching ImproperlyConfigured suffices for 1. but 2. requires
        # catching all exceptions.
        pass
    else:
        if ('django.contrib.auth.context_processors.auth'
                not in default_template_engine.context_processors and
                'django.contrib.auth.backends.ModelBackend' in settings.AUTHENTICATION_BACKENDS):
            missing_template = checks.Error(
                "'django.contrib.auth.context_processors.auth' must be in "
                "TEMPLATES in order to use the admin application.",
                id="admin.E402"
            )
            errors.append(missing_template)
    return errors

def get_context_data(self, **kwargs):
        tags = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for tag_name, tag_func in library.tags.items():
                    title, body, metadata = utils.parse_docstring(tag_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'tag', _('tag:') + tag_name)
                    if body:
                        body = utils.parse_rst(body, 'tag', _('tag:') + tag_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'tag', _('tag:') + tag_name)
                    tag_library = module_name.split('.')[-1]
                    tags.append({
                        'name': tag_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'tags': tags})
        return super(TemplateTagIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        filters = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for filter_name, filter_func in library.filters.items():
                    title, body, metadata = utils.parse_docstring(filter_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'filter', _('filter:') + filter_name)
                    if body:
                        body = utils.parse_rst(body, 'filter', _('filter:') + filter_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'filter', _('filter:') + filter_name)
                    tag_library = module_name.split('.')[-1]
                    filters.append({
                        'name': filter_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'filters': filters})
        return super(TemplateFilterIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                if os.path.exists(template_file):
                    with open(template_file) as f:
                        template_contents = f.read()
                else:
                    template_contents = ''
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': template_contents,
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def __init__(self, *args):
        self.template_cache = {}
        try:
            # Django 1.10 args = (engine, loaders)
            self._loaders = args[1]
        except IndexError:
            # Django <= 1.7 args = (loaders, )
            self._loaders = args[0]
        self._cached_loaders = []

        try:
            from django.template.loader import find_template_loader as _find_template_loader
        except:
            _find_template_loader = Engine.get_default().find_template_loader
        self._find_template_loader = _find_template_loader

def get_context_data(self, **kwargs):
        tags = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for tag_name, tag_func in library.tags.items():
                    title, body, metadata = utils.parse_docstring(tag_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'tag', _('tag:') + tag_name)
                    if body:
                        body = utils.parse_rst(body, 'tag', _('tag:') + tag_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'tag', _('tag:') + tag_name)
                    tag_library = module_name.split('.')[-1]
                    tags.append({
                        'name': tag_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'tags': tags})
        return super(TemplateTagIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        filters = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for filter_name, filter_func in library.filters.items():
                    title, body, metadata = utils.parse_docstring(filter_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'filter', _('filter:') + filter_name)
                    if body:
                        body = utils.parse_rst(body, 'filter', _('filter:') + filter_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'filter', _('filter:') + filter_name)
                    tag_library = module_name.split('.')[-1]
                    filters.append({
                        'name': filter_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'filters': filters})
        return super(TemplateFilterIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': lambda: open(template_file).read() if os.path.exists(template_file) else '',
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def check_dependencies(**kwargs):
    """
    Check that the admin's dependencies are correctly installed.
    """
    errors = []
    # contrib.contenttypes must be installed.
    if not apps.is_installed('django.contrib.contenttypes'):
        missing_app = checks.Error(
            "'django.contrib.contenttypes' must be in INSTALLED_APPS in order "
            "to use the admin application.",
            id="admin.E401",
        )
        errors.append(missing_app)
    # The auth context processor must be installed if using the default
    # authentication backend.
    try:
        default_template_engine = Engine.get_default()
    except Exception:
        # Skip this non-critical check:
        # 1. if the user has a non-trivial TEMPLATES setting and Django
        #    can't find a default template engine
        # 2. if anything goes wrong while loading template engines, in
        #    order to avoid raising an exception from a confusing location
        # Catching ImproperlyConfigured suffices for 1. but 2. requires
        # catching all exceptions.
        pass
    else:
        if ('django.contrib.auth.context_processors.auth'
                not in default_template_engine.context_processors and
                'django.contrib.auth.backends.ModelBackend' in settings.AUTHENTICATION_BACKENDS):
            missing_template = checks.Error(
                "'django.contrib.auth.context_processors.auth' must be in "
                "TEMPLATES in order to use the admin application.",
                id="admin.E402"
            )
            errors.append(missing_template)
    return errors

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': lambda: open(template_file).read() if os.path.exists(template_file) else '',
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that admin and contenttypes apps are
        installed, as well as the auth context processor.
        """
        if not apps.is_installed('django.contrib.admin'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.admin' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        if not apps.is_installed('django.contrib.contenttypes'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.contenttypes' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        try:
            default_template_engine = Engine.get_default()
        except Exception:
            # Skip this non-critical check:
            # 1. if the user has a non-trivial TEMPLATES setting and Django
            #    can't find a default template engine
            # 2. if anything goes wrong while loading template engines, in
            #    order to avoid raising an exception from a confusing location
            # Catching ImproperlyConfigured suffices for 1. but 2. requires
            # catching all exceptions.
            pass
        else:
            if ('django.contrib.auth.context_processors.auth'
                    not in default_template_engine.context_processors):
                raise ImproperlyConfigured(
                    "Enable 'django.contrib.auth.context_processors.auth' "
                    "in your TEMPLATES setting in order to use the admin "
                    "application.")

def get_context_data(self, **kwargs):
        tags = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for tag_name, tag_func in library.tags.items():
                    title, body, metadata = utils.parse_docstring(tag_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'tag', _('tag:') + tag_name)
                    if body:
                        body = utils.parse_rst(body, 'tag', _('tag:') + tag_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'tag', _('tag:') + tag_name)
                    tag_library = module_name.split('.')[-1]
                    tags.append({
                        'name': tag_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'tags': tags})
        return super(TemplateTagIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        filters = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for filter_name, filter_func in library.filters.items():
                    title, body, metadata = utils.parse_docstring(filter_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'filter', _('filter:') + filter_name)
                    if body:
                        body = utils.parse_rst(body, 'filter', _('filter:') + filter_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'filter', _('filter:') + filter_name)
                    tag_library = module_name.split('.')[-1]
                    filters.append({
                        'name': filter_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'filters': filters})
        return super(TemplateFilterIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': lambda: open(template_file).read() if os.path.exists(template_file) else '',
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that admin and contenttypes apps are
        installed, as well as the auth context processor.
        """
        if not apps.is_installed('django.contrib.admin'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.admin' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        if not apps.is_installed('django.contrib.contenttypes'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.contenttypes' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        try:
            default_template_engine = Engine.get_default()
        except Exception:
            # Skip this non-critical check:
            # 1. if the user has a non-trivial TEMPLATES setting and Django
            #    can't find a default template engine
            # 2. if anything goes wrong while loading template engines, in
            #    order to avoid raising an exception from a confusing location
            # Catching ImproperlyConfigured suffices for 1. but 2. requires
            # catching all exceptions.
            pass
        else:
            if ('django.contrib.auth.context_processors.auth'
                    not in default_template_engine.context_processors):
                raise ImproperlyConfigured(
                    "Enable 'django.contrib.auth.context_processors.auth' "
                    "in your TEMPLATES setting in order to use the admin "
                    "application.")

def get_context_data(self, **kwargs):
        tags = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for tag_name, tag_func in library.tags.items():
                    title, body, metadata = utils.parse_docstring(tag_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'tag', _('tag:') + tag_name)
                    if body:
                        body = utils.parse_rst(body, 'tag', _('tag:') + tag_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'tag', _('tag:') + tag_name)
                    tag_library = module_name.split('.')[-1]
                    tags.append({
                        'name': tag_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'tags': tags})
        return super(TemplateTagIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        filters = []
        try:
            engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            app_libs = sorted(engine.template_libraries.items())
            builtin_libs = [('', lib) for lib in engine.template_builtins]
            for module_name, library in builtin_libs + app_libs:
                for filter_name, filter_func in library.filters.items():
                    title, body, metadata = utils.parse_docstring(filter_func.__doc__)
                    if title:
                        title = utils.parse_rst(title, 'filter', _('filter:') + filter_name)
                    if body:
                        body = utils.parse_rst(body, 'filter', _('filter:') + filter_name)
                    for key in metadata:
                        metadata[key] = utils.parse_rst(metadata[key], 'filter', _('filter:') + filter_name)
                    tag_library = module_name.split('.')[-1]
                    filters.append({
                        'name': filter_name,
                        'title': title,
                        'body': body,
                        'meta': metadata,
                        'library': tag_library,
                    })
        kwargs.update({'filters': filters})
        return super(TemplateFilterIndexView, self).get_context_data(**kwargs)

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': lambda: open(template_file).read() if os.path.exists(template_file) else '',
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that admin and contenttypes apps are
        installed, as well as the auth context processor.
        """
        if not apps.is_installed('django.contrib.admin'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.admin' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        if not apps.is_installed('django.contrib.contenttypes'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.contenttypes' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        try:
            default_template_engine = Engine.get_default()
        except Exception:
            # Skip this non-critical check:
            # 1. if the user has a non-trivial TEMPLATES setting and Django
            #    can't find a default template engine
            # 2. if anything goes wrong while loading template engines, in
            #    order to avoid raising an exception from a confusing location
            # Catching ImproperlyConfigured suffices for 1. but 2. requires
            # catching all exceptions.
            pass
        else:
            if ('django.contrib.auth.context_processors.auth'
                    not in default_template_engine.context_processors):
                raise ImproperlyConfigured(
                    "Enable 'django.contrib.auth.context_processors.auth' "
                    "in your TEMPLATES setting in order to use the admin "
                    "application.")

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': lambda: open(template_file).read() if os.path.exists(template_file) else '',
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################

def check_dependencies(self):
        """
        Check that all things needed to run the admin have been correctly installed.

        The default implementation checks that admin and contenttypes apps are
        installed, as well as the auth context processor.
        """
        if not apps.is_installed('django.contrib.admin'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.admin' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        if not apps.is_installed('django.contrib.contenttypes'):
            raise ImproperlyConfigured(
                "Put 'django.contrib.contenttypes' in your INSTALLED_APPS "
                "setting in order to use the admin application.")
        try:
            default_template_engine = Engine.get_default()
        except Exception:
            # Skip this non-critical check:
            # 1. if the user has a non-trivial TEMPLATES setting and Django
            #    can't find a default template engine
            # 2. if anything goes wrong while loading template engines, in
            #    order to avoid raising an exception from a confusing location
            # Catching ImproperlyConfigured suffices for 1. but 2. requires
            # catching all exceptions.
            pass
        else:
            if ('django.contrib.auth.context_processors.auth'
                    not in default_template_engine.context_processors):
                raise ImproperlyConfigured(
                    "Enable 'django.contrib.auth.context_processors.auth' "
                    "in your TEMPLATES setting in order to use the admin "
                    "application.")

def get_context_data(self, **kwargs):
        template = self.kwargs['template']
        templates = []
        try:
            default_engine = Engine.get_default()
        except ImproperlyConfigured:
            # Non-trivial TEMPLATES settings aren't supported (#24125).
            pass
        else:
            # This doesn't account for template loaders (#24128).
            for index, directory in enumerate(default_engine.dirs):
                template_file = os.path.join(directory, template)
                templates.append({
                    'file': template_file,
                    'exists': os.path.exists(template_file),
                    'contents': lambda: open(template_file).read() if os.path.exists(template_file) else '',
                    'order': index,
                })
        kwargs.update({
            'name': template,
            'templates': templates,
        })
        return super(TemplateDetailView, self).get_context_data(**kwargs)


####################
# Helper functions #
####################