AngularJS在自定义指令中传递Model

来源：互联网发布：淘宝助手官方网站编辑：程序博客网时间：2024/05/17 04:20

本文是对AngularJS权威指南8.2节的理解，书中的解释比较混乱，花了一些时间才理解作者表达的意思。

假如我们创建了一个指令，用于生成一个包含input和a标签。如果我们想input标签的内容通过ng-model的方式传递出去（例如传递到指令外的另一个input），我们可能会这么写：

<code class="language-JavaScript hljs handlebars has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="xml" style="box-sizing: border-box;"><span class="hljs-doctype" style="color: rgb(102, 0, 102); box-sizing: border-box;"><!doctype html></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">html</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">ng-app</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"myApp"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">head</span>></span>    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">src</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"angular.js"</span>></span><span class="javascript" style="box-sizing: border-box;"></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">head</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">body</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">input</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"text"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">ng-model</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"myUrl"</span>/></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">my-directive</span>     <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">some-attr</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"</span></span></span><span class="hljs-expression" style="box-sizing: border-box;">{{<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">myUrl</span>}}</span><span class="xml" style="box-sizing: border-box;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"</span>     <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">my-link-text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"Click me to go to Google"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="javascript" style="box-sizing: border-box;">    angular.module(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'myApp'</span>, [])            .directive(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'myDirective'</span>, <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span><span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">()</span> {</span>                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> {                    restrict: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'A'</span>,                    replace: <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">true</span>,                    scope: {                        myUrl: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'@someAttr'</span>,                        myLinkText: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'@'</span>                    },                    template: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'\          <div>\            <input type="text" ng-model="myUrl" />\            <a href="</span></span></span><span class="hljs-expression" style="box-sizing: border-box;">{{<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">myUrl</span>}}</span><span class="xml" style="box-sizing: border-box;"><span class="javascript" style="box-sizing: border-box;"><span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"></span></span></span><span class="hljs-expression" style="box-sizing: border-box;">{{<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">myLinkText</span>}}</span><span class="xml" style="box-sizing: border-box;"><span class="javascript" style="box-sizing: border-box;"><<span class="hljs-regexp" style="color: rgb(0, 136, 0); box-sizing: border-box;">/a>\          </</span>div>\        <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'                }            })</span></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">body</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">html</span>></span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li></ul>

生成的HTML如下图所示：

这里写图片描述

但是这不能达到我们的预期：数据只能从第一个input传递到第二个input，而不能从第二个input传递到第一个input。

原因是指令内部有独立的作用域，指令内的{{myUrl}}不能直接被外部共享。

将代码做如下修改，可以实现被外部共享，注意修改的部分有注释：

<code class="language-JavaScript hljs handlebars has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="xml" style="box-sizing: border-box;"><span class="hljs-doctype" style="color: rgb(102, 0, 102); box-sizing: border-box;"><!doctype html></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">html</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">ng-app</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"myApp"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">head</span>></span>    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">meta</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">charset</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"utf-8"</span>/></span>    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">src</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"angular.js"</span>></span><span class="javascript" style="box-sizing: border-box;"></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">head</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">body</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">input</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"text"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">ng-model</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"myUrl"</span>/></span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"><!--*****************************************--></span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"><!--</span></span><span class="hljs-expression" style="box-sizing: border-box;">{{<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">myUrl</span>}}</span><span class="xml" style="box-sizing: border-box;"><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">改为了myUrl--></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">my-directive</span>     <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">some-attr</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"myUrl"</span>     <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">my-link-text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"Click me to go to Google"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"><!--*****************************************--></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="javascript" style="box-sizing: border-box;">    angular.module(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'myApp'</span>, [])            .directive(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'myDirective'</span>, <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span><span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">()</span> {</span>                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> {                    restrict: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'A'</span>,                    replace: <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">true</span>,                    scope: {                        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//*****************************************</span>                        myUrl: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'=someAttr'</span>,<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//@修改为了=</span>                        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//*****************************************</span>                        myLinkText: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'@'</span>                    },                    template: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'\          <div>\            <input type="text" ng-model="myUrl" />\            <a href="</span></span></span><span class="hljs-expression" style="box-sizing: border-box;">{{<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">myUrl</span>}}</span><span class="xml" style="box-sizing: border-box;"><span class="javascript" style="box-sizing: border-box;"><span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"></span></span></span><span class="hljs-expression" style="box-sizing: border-box;">{{<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">myLinkText</span>}}</span><span class="xml" style="box-sizing: border-box;"><span class="javascript" style="box-sizing: border-box;"><<span class="hljs-regexp" style="color: rgb(0, 136, 0); box-sizing: border-box;">/a>\          </</span>div>\        <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'                }            })</span></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">body</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">html</span>></span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li></ul>

总结

指令内部model共享到外部，只需要将”@”改为”=”，并且将对应的指令的{{}}删掉即可。

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