我有以下几点:

<div>{{modal.title}}</div>

有没有一种方法可以限制字符串的长度,比如20个字符?

一个更好的问题是,有没有一种方法可以将字符串更改为截断并显示。如果超过20个字符?


当前回答

可以使用筛选器限制字符串或数组的长度。看看AngularJS团队写的这个。

其他回答

我发现最简单的解决方案是让材料设计(1.0.0-rc4)来做这项工作。md-input-container将为您完成这项工作。它连接了字符串,添加了省略,它还有一个额外的好处,允许你点击它来获得全文,所以它是整个玉米卷饼。您可能需要设置md-input-container的宽度。

HTML:

<md-input-container>
   <md-select id="concat-title" placeholder="{{mytext}}" ng-model="mytext" aria-label="label">
      <md-option ng-selected="mytext" >{{mytext}}
      </md-option>
   </md-select>
</md-input-container>

CS:

#concat-title .md-select-value .md-select-icon{
   display: none; //if you want to show chevron remove this
}
#concat-title .md-select-value{
   border-bottom: none; //if you want to show underline remove this
}

我使用了一套非常有用的滤镜库“Angular-filter”,其中一个叫做“truncate”的也很有用。

https://github.com/a8m/angular-filter#truncate

用法是:

text | truncate: [length]: [suffix]: [preserve-boolean]

使用自定义Angular过滤器限制字数: 下面是我如何使用Angular过滤器来限制使用自定义过滤器显示的字数。

HTML:

<span>{{dataModelObject.TextValue | limitWordsTo: 38}} ......</span>

角/ Javascript代码

angular.module('app')
.filter('limitWordsTo', function () {
    return function (stringData, numberOfWords) {
        //Get array of words (determined by spaces between words)
        var arrayOfWords = stringData.split(" ");

        //Get loop limit
        var loopLimit = numberOfWords > arrayOfWords.length ? arrayOfWords.length : numberOfWords;

        //Create variables to hold limited word string and array iterator
        var limitedString = '', i;
        //Create limited string bounded by limit passed in
        for (i = 0; i < loopLimit; i++) {
            if (i === 0) {
                limitedString = arrayOfWords[i];
            } else {
                limitedString = limitedString + ' ' + arrayOfWords[i];
            }
        }
        return limitedString;
    }; 
}); //End filter

更优雅的解决方案:

HTML:

<html ng-app="phoneCat">
  <body>
    {{ "AngularJS string limit example" | strLimit: 20 }}
  </body>
</html>

角代码:

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

 phoneCat.filter('strLimit', ['$filter', function($filter) {
   return function(input, limit) {
      if (! input) return;
      if (input.length <= limit) {
          return input;
      }

      return $filter('limitTo')(input, limit) + '...';
   };
}]);

演示:

http://code-chunk.com/chunks/547bfb3f15aa1/str-limit-implementation-for-angularjs

下面是一个用于截断文本的自定义过滤器。它的灵感来自于EpokK的解决方案,但根据我的需求和口味进行了修改。

angular.module('app').filter('truncate', function () {

    return function (content, maxCharacters) {

        if (content == null) return "";

        content = "" + content;

        content = content.trim();

        if (content.length <= maxCharacters) return content;

        content = content.substring(0, maxCharacters);

        var lastSpace = content.lastIndexOf(" ");

        if (lastSpace > -1) content = content.substr(0, lastSpace);

        return content + '...';
    };
});

这里是单元测试,所以你可以看到它应该如何表现:

describe('truncate filter', function () {

    var truncate,
        unfiltered = " one two three four ";

    beforeEach(function () {

        module('app');

        inject(function ($filter) {

            truncate = $filter('truncate');
        });
    });

    it('should be defined', function () {

        expect(truncate).to.be.ok;
    });

    it('should return an object', function () {

        expect(truncate(unfiltered, 0)).to.be.ok;
    });

    it('should remove leading and trailing whitespace', function () {

        expect(truncate(unfiltered, 100)).to.equal("one two three four");
    });

    it('should truncate to length and add an ellipsis', function () {

        expect(truncate(unfiltered, 3)).to.equal("one...");
    });

    it('should round to word boundaries', function () {

        expect(truncate(unfiltered, 10)).to.equal("one two...");
    });

    it('should split a word to avoid returning an empty string', function () {

        expect(truncate(unfiltered, 2)).to.equal("on...");
    });

    it('should tolerate non string inputs', function () {

        expect(truncate(434578932, 4)).to.equal("4345...");
    });

    it('should tolerate falsey inputs', function () {

        expect(truncate(0, 4)).to.equal("0");

        expect(truncate(false, 4)).to.equal("fals...");
    });
});