如何编写 angularjs 过滤器来搜索字符串片段/字符串序列 [英] How can I write an angularjs filter to search for string fragments/sequences of strings

问题描述

我正在尝试编写一个 angularjs 自定义过滤器，用于检查一组国家/地区是否包含用户输入的搜索字符串.

I'm trying to write an angularjs custom filter that checks whether an array of countries contains a search string entered by the user.

字符串可以由一个字母(例如E")、n 个字母的片段(例如lan")或整个单词(例如England")组成.

The string can consist of one letter (e.g. 'E'), or a fragment of n-letters (e.g. 'lan') or an entire word (e.g. 'England').

在每种情况下，都应返回包含该字母或该片段的所有国家/地区，因此E"将返回England"、Estonia"等，而lan"将返回England"、Ireland"等.

In every case, all countries containing that one letter or that fragment should be returned, so 'E' would return 'England', 'Estonia' etc. while 'lan' would return 'England', 'Ireland', etc.

到目前为止，我的过滤器返回整个国家或单个字母，但我在处理字符串片段时遇到困难:

So far my filter returns the entire country or single letters but I'm having difficulty with string fragments:

1. HTML 模板:

1. HTML Template:

<input ng-model="filter.text" type="search" placeholder="Filter..."/>

<ul>
   <li ng-repeat="item in data | listfilter:filter.text">
</ul>

angularJS

angularJS

angular.module('sgComponents').filter('listfilter',[ function () {
return function(items, searchText) {
    var filtered = [];            

    angular.forEach(items, function(item) {
        if(item.label === searchText) { // matches whole word, e.g. 'England'
            filtered.push(item);
        }
        var letters = item.label.split('');
        _.each(letters, function(letter) {
            if (letter === searchText) { // matches single letter, e.g. 'E'
                console.log('pushing');
                filtered.push(item);
            }
        });
        // code to match letter fragments, e.g. 'lan'
    });
    return filtered;
};
}]);

推荐答案

比那简单多了，使用String.indexOf()函数:

It is much simpler than that, use the String.indexOf() function:

angular.forEach(items, function(item) {
    if( item.label.indexOf(searchText) >= 0 ) filtered.push(item);
});

您可能希望将两个字符串 .toLowerCase() 都转换为不区分大小写的匹配:

You may want to turn both strings .toLowerCase() to do case-insensitive matching:

searchText = searchText.toLowerCase();
angular.forEach(items, function(item) {
    if( item.label.toLowerCase().indexOf(searchText) >= 0 ) filtered.push(item);
});

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