javascript - AngularJS:ng-options 仅添加每个可能的字段值

Question

假设我有一个类似于 AngularJS ngOptions 文档中的数组

[
  {name:'black', shade:'dark'},
  {name:'white', shade:'light', notAnOption: true},
  {name:'red', shade:'dark'},
  {name:'blue', shade:'dark', notAnOption: true},
  {name:'yellow', shade:'light', notAnOption: false}
];

使用...

<select ng-model="myColor" ng-options="color.name group by color.shade for color in colors">

产生...

dark  
  black  
  red  
  blue
light  
  white
  yellow

我想按黑暗和光明过滤值，所以我只想...

dark  
light

是否可以使用 ng-options 来完成此任务？

Answer 1

像这样使用过滤器

 <select ng-model="myColor" ng-options="color.shade for color in Colors | unique:'shade'"></select>

添加带有“unique”的 AngularJS 过滤器

app.filter('unique', function () {
return function (input, key) {
    var unique = {};
    var uniqueList = [];
    for (var i = 0; i < input.length; i++) {
        if (typeof unique[input[i][key]] == "undefined") {
            unique[input[i][key]] = "";
            uniqueList.push(input[i]);
        }
    }
    return uniqueList;
   };
 });