差异$ AngularJS 1.0和1.2之间的插值 [英] Difference in $interpolate between AngularJS 1.0 and 1.2

问题描述

我在一行写一个过滤器，以格式的地址。将传递到过滤器的对象的格式为：

I'm writing a filter to format addresses in a single line. The object that will be passed into the filter has the format:

{
  Line1: "123 Main St.",
  Line2: "Apartment 2", // Optional
  City: "Chicago",
  State: "IL",
  Zip: "60623"
}

我有以下至今：

angular.module('myApp')
  .filter('address', function ($interpolate) {
    return function (input, template) {

      if (input === null || !angular.isDefined(input)) {
        return input;
      }

      // template is optional. If not provided, use the following    
      if(!template) {
        template = '{{Line1}}, {{Line2 ? Line2 + \', \' : \'\'}}{{City}} {{State}} {{Zip}}';
      }

      try {
        var parsedTemplate = $interpolate(template);
      } catch (e) {
        console.log(parsedTemplate, template, input, e)
        return input;
      }

      // Compile the template in the context of the input object
      return parsedTemplate(input);
    };
  });

在1.2角这工作正常。然而，在角1.0它失败，出现错误错误：词法错误：在6-6列意外的下一个字符前pression [2号线[？]？ 2号线+'，'：''] 我的想法是角1.0不支持三元运算符 $插值 D EX pressions ，但我找不到在角1.2加入的任何文件表明支持。

In Angular 1.2 this works fine. However, in Angular 1.0 it fails with the error Error: Lexer Error: Unexpected next character at columns 6-6 [?] in expression [Line2 ? Line2 + ', ' : '']. My thought is Angular 1.0 doesn't support the ternary operator $interpolated expressions, but I couldn't find any documentation suggesting that support was added in Angular 1.2.

有没有使用角1.0三元运算符的方式，如果没有我怎样才能解决这个限制得到什么？

Is there a way to use the ternary operator in Angular 1.0, and if not how can I get around that restriction?

（加分 - 文档在没有提到这种变化，或提交的角混帐回购协议所做的更改）

(Bonus points - where in the documentation does it mention this change, or which commit in the Angular git repo made the change?)

推荐答案

我意识到，之前我升级到1.1.5，我的解决方法在插值前pressions使用三元运算符是使用＆功放;＆安培; 和 || （如 someCondition和放大器;＆安培; TruthyResult || FalseyResult ）以有效地获得相同的结果。这里是你如何把它们运用到你的code：

I realized that before I upgraded to 1.1.5, my workaround to using a ternary operator in interpolated expressions was to use && and || (like someCondition && TruthyResult || FalseyResult) to effectively get the same result. Here's how you'd apply it to your code:

template = '{{Line1}}, {{Line2 && (Line2 + \', \') || \'\'}}{{City}} {{State}} {{Zip}}';

DEMO： http://jsfiddle.net/f9n6r/

与此设置唯一的问题是，如果在 TruthyResult 实际上并没有返回的东西truthy，在 FalseyResult 将返回（使用的只是自然＆放大器;＆安培; 和 || 这样，相比三元运算符）。在您的code虽然，（2号线+ \\'，\\'）绝不会因为falsey的 \\'，\\'，所以它不会是一个问题在这里。但在更一般的情况下，也可能是

The only problem with this setup is if the the TruthyResult doesn't actually return something truthy, the FalseyResult will be returned (just the nature of using && and || like this, compared to the ternary operator). In your code though, (Line2 + \', \') will never be falsey because of the \', \', so it won't be a problem here. But in a more general case, it could be.

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