anglejs ng-click静默地吃错误

如果我有这样的ng点击：
NG-点击= “越野车()”
并单击，控制台上不会生成错误信息。

这使得调试有点棘手。

为什么不生成错误消息？我能做什么？

角度表达

实际上，这不是特别的，点击ng，这是角度表达式的默认行为。

buggy()不使用常规javascript进行评估。它使用$ parse进行评估。

$ parse计算表达式并返回一个可以对范围运行的函数。

$ parse只有当表达式无效时才会记录错误。

角度表达评估是宽容的，我想不出有什么办法通过。

为什么表达是宽恕的？

Angular表达式被原谅的未定义和null的理由与数据绑定有关。当绑定变量被编译到DOM中时，绑定变量可能最初未定义或为空，当绑定变量取决于承诺时，真正明确的示例就是绑定变量。角色团队决定，除非出现错误信息，直到该承诺得到解决，否则最好继续默默地继续。

从Angular guide to expressions：

It makes more sense to show nothing than to throw an exception if a is
undefined (perhaps we are waiting for the server response,and it will
become defined soon). If expression evaluation wasn’t forgiving we’d
have to write bindings that clutter the code,for example:
{{((a||{}).b||{}).c}}

另请参见：https://groups.google.com/forum/m/#!topic/angular/HRVOUKEHLFw

Angular expressions：

Expressions are JavaScript-like code snippets that are usually placed in bindings such as {{ expression }}. Expressions are processed by the $parse service. Expressions are often post processed using filters to create a more user-friendly format.

Angular Expressions vs. JS Expressions

It might be tempting to think of Angular view expressions as JavaScript expressions,but that is not entirely correct,since Angular does not use a JavaScript eval() to evaluate expressions. You can think of Angular expressions as JavaScript expressions with following differences:

• Attribute Evaluation: evaluation of all properties are against the scope doing the evaluation,unlike in JavaScript where the expressions are evaluated against the global window.

• Forgiving: expression evaluation is forgiving to undefined and null,unlike in JavaScript,where trying to evaluate undefined properties can generate ReferenceError or TypeError.

• No Control Flow Statements: you cannot do any of the following in angular expression: conditionals,loops,or throw.

原文地址：https://www.jb51.cc/angularjs/144519.html