我在这里找到了一个很棒的树指令。原文:http://jsfiddle.net/n8dPm/
我一直在试图通过其他几个做题,要了解它的功能。我不太明白呈现树指令的递归调用是如何工作的。主要是编译功能
compiledContents
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compile: function(tElement, tAttr) { var contents = tElement.contents().remove(); var compiledContents; return function(scope, iElement, iAttr) { if(!compiledContents) { compiledContents = $compile(contents); } compiledContents(scope, function(clone, scope) { iElement.append(clone); }); }; },
Ng网站上有一些很棒的文档(我认为是最好的文档)。启动和运行时循环的概述非常有帮助:http : //docs.angularjs.org/guide/concepts
在较高的级别上,当Ng首次启动时,它将从ng-app所在的位置开始编译DOM(就像Ng的另一条指令一样)。这意味着它将遍历元素并查找链接至$ rootScope(编译/链接过程中属于原型继承链设置的所有作用域的根)所需的指令和表达式。如果是指令,则也将在其上执行编译过程。编译过程将采用在HTML中找到的所有Ng指令,并根据分配的优先级对它们进行优先级排序,或者假定优先级为零。当它们全部排序后,它将为返回链接功能的指令执行编译功能。在上面的示例中,有两个show链接函数,下面将对其进行注释以及将其链接到此说明的其他注释。
执行链接功能,链接功能将范围和指令链接在一起并生成视图。这可能包括HTML / transclude,因此可以将其添加到指令模板中ng- transclude指令的位置(该指令的模板为transclude时,将对其应用相同的过程)。
因此,这是上面略微更正的自定义指令的注释:
module.directive("tree", function($compile) { //Here is the Directive Definition Object being returned //which is one of the two options for creating a custom directive //http://docs.angularjs.org/guide/directive return { restrict: "E", //We are stating here the HTML in the element the directive is applied to is going to be given to //the template with a ng-transclude directive to be compiled when processing the directive transclude: true, scope: {family: '='}, template: '<ul>' + //Here we have one of the ng-transclude directives that will be give the HTML in the //element the directive is applied to '<li ng-transclude></li>' + '<li ng-repeat="child in family.children">' + //Here is another ng-transclude directive which will be given the same transclude HTML as //above instance //Notice that there is also another directive, 'tree', which is same type of directive this //template belongs to. So the directive in the template will handle the ng-transclude //applied to the div as the transclude for the recursive compile call to the tree //directive. The recursion will end when the ng-repeat above has no children to //walkthrough. In other words, when we hit a leaf. '<tree family="child"><div ng-transclude></div></tree>' + '</li>' + '</ul>', compile: function(tElement, tAttr, transclude) { //We are removing the contents/innerHTML from the element we are going to be applying the //directive to and saving it to adding it below to the $compile call as the template var contents = tElement.contents().remove(); var compiledContents; return function(scope, iElement, iAttr) { if(!compiledContents) { //Get the link function with the contents frome top level template with //the transclude compiledContents = $compile(contents, transclude); } //Call the link function to link the given scope and //a Clone Attach Function, http://docs.angularjs.org/api/ng.$compile : // "Calling the linking function returns the element of the template. // It is either the original element passed in, // or the clone of the element if the cloneAttachFn is provided." compiledContents(scope, function(clone, scope) { //Appending the cloned template to the instance element, "iElement", //on which the directive is to used. iElement.append(clone); }); }; } }; });
整个工作正常:http://jsfiddle.net/DsvX6/7/