如何在自定义指令中获取ng-model值

Question

我在这里搜索了SO并尝试了我找到的答案,但我似乎无法从我的自定义指令的ngModel中获取模型值.

这是指令

/*
 *usage: <markdown ng:model="someModel.content"></markdown>
 */
breathingRoom.directive('markdown', function () {
    var nextId = 0;
    return {
        require: 'ngModel',
        replace: true,
        restrict: 'E',
        template: '<div class="pagedown-bootstrap-editor"></div>',
        link:function (scope, element, attrs, ngModel) {

            var editorUniqueId = nextId++;
            element.html($('<div>' +
                '<div class="wmd-panel">' +
                '<div id="wmd-button-bar-' + editorUniqueId + '"></div>' +
                '<textarea class="wmd-input" id="wmd-input-' + editorUniqueId + '">{{modelValue()}}' +
                '</textarea>' +
                '</div>' +
                '<div id="wmd-preview-' + editorUniqueId + '" class="wmd-panel wmd-preview"></div>' +
                '</div>'));

            var converter = new Markdown.Converter();

            var help = function () {
                // 2DO: add nice modal dialog
                alert("Do you need help?");
            };

            var editor = new Markdown.Editor(converter, "-" + editorUniqueId, {
                handler: help
            });

            editor.run();


            // local -> parent scope change (model)
            jQuery("#wmd-input-" + editorUniqueId).on('change', function () {
                var rawContent = $(this).val();
                ngModel.$setViewValue(rawContent);
                scope.$apply();
            });

            // parent scope -> local change
            scope.modelValue = function () {
                console.log('modelvalue - ', ngModel.$viewValue);
                return ngModel.$viewValue;
            };
        }
    };
});

这是HTML

<markdown ng-class="{error: (moduleForm.Description.$dirty && moduleForm.Description.$invalid) || (moduleForm.Description.$invalid && submitted)}"
          id="Description" 
          name="Description" 
          placeholder="Description" 
          ng-model="module.description" 
          required></markdown>   

这里的问题是输出很简单

{{modelValue()}}

---

我也试过创建一个私有方法

function getModelValue() {
    console.log(ngModel.$viewValue);
    return ngModel.$viewValue;
}

然后将一个模板行更改为

'<textarea class="wmd-input" id="wmd-input-' + editorUniqueId + '">' + getModelValue() +

但后来的输出是

NaN

我哪里错了？

---

如果重要,这是我的脚本的顺序(不包括供应商脚本)

<script src="app.js"></script>
<script src="directives/backButtonDirective.js"></script>
<script src="directives/bootstrapSwitchDirective.js"></script>
<script src="directives/markdownDirective.js"></script>
<script src="directives/trackActiveDirective.js"></script>
<script src="services/alertService.js"></script>
<script src="services/roleService.js"></script>
<script src="services/moduleService.js"></script>
<script src="services/changePasswordService.js"></script>
<script src="services/userService.js"></script>
<script src="controllers/usersController.js"></script>
<script src="controllers/userController.js"></script>
<script src="controllers/moduleController.js"></script>
<script src="controllers/modulesController.js"></script>

Answer 1

插入的HTML没有被编译.最简单的方法是将其移入模板,或使用ng-transclude进行调查.这是将其移动到模板中的示例.

plunker

breathingRoom.directive('markdown', function () {
    var nextId = 0;
    return {
        require: 'ngModel',
        replace: true,
        restrict: 'E',
        template: '<div class="pagedown-bootstrap-editor"><div class="wmd-panel">' +
                '<div id="wmd-button-bar-{{editorUniqueId}}"></div>' +
                '<textarea class="wmd-input" id="wmd-input-{{editorUniqueId}}">{{modelValue()}}' +
                '</textarea>' +
                '</div>' +
                '<div id="wmd-preview-{{editorUniqueId}}" class="wmd-panel wmd-preview"></div>' +
                '</div></div>',
        link:function (scope, element, attrs, ngModel) {

            scope.editorUniqueId = nextId++;

            // parent scope -> local change
            scope.modelValue = function () {
                console.log('modelvalue - ' + ngModel.$viewValue);
                return ngModel.$viewValue;
            };
        }
    };
});

Answer 2

您实际上并没有解析模型,因为{{modelValue()}}表达式只是您在链接函数中构建的HTML字符串的一部分.

您应该将编辑器标记移动到template可以绑定到的标记ng-model.

假设目标是为Markdown编辑器创建必要的HTML标记,然后显示已转换的 markdown 的预览,我会将其分为两个角色:

1. 自定义标记的指令
2. 用于将值实际转换为markdown的过滤器:

标记:

<div ng-app="app" ng-controller="DemoCtrl">
    <h3>Markdown editor</h3>
    <markdown-editor ng-model="markdown"></markdown-editor>
</div>

JavaScript的:

var app = angular.module('app', []);

app.filter('markdown', function () {
    return function (input) {
        return input.toUpperCase(); // this is where you'd convert your markdown
    };
});

app.directive('markdownEditor', function () {
    return {
        restrict: 'E',
        scope: {
            ngModel: "="
        },
        template:
            '<div>' +
            '<textarea ng-model="ngModel"></textarea>' +
            '<div class="preview">{{ ngModel | markdown }}</div>' +
            '</div>'
    };
});

app.controller('DemoCtrl', function ($scope) {
    $scope.markdown = "**hello world**";
});

的=范围设置了一个双向传递给属性绑定ng-model和{{ ngModel | markdown }}管道的值ngModel到markdown过滤器.

http://jsfiddle.net/benfosterdev/jY3ZK/