Using filter to create array, then using that array to filter ng-options

问题

I am using isteven-multi-select to output an array of objects from a select element's multiple selections.
```
[
  { category: "Adventure", ticked: true },
  { category: "Strategy", ticked: true }
]
```

2. Then using angular.forEach to change the array of objects into an array of the category values.

$scope.testOutput = function () {
    angular.forEach($scope.output, function(value, prop, obj) {
        var categoryFiltered = [];

        categoryFiltered.push(value.category);
        console.log(categoryFiltered);
    });
};

categoryFiltered = ["Adventure", "Strategy"];

3. Now I need to use the categoryFiltered array to filter out the other categories in an ng-repeat.

HTML

ul
  li(ng-repeat='item in items | filter: {categories: categoryFiltered')

MongoDB populating items

        {
          year: 1962,
          categories: ["Adventure"]
        }, {
          year: 1972,
          categories: ["Fishing"]
        }, {
          year: 1982,
          categories: ["Strategy"]
        }

What is the best way to achieve this?

回答1:

Write a custom filter, then you can filter the categories however you like (eg. do you want to filter items that match ALL the categories specified? Or only some?).

Here's a plunkr example: http://plnkr.co/edit/Lv11QWumN7ktjfS15RpY?p=preview

Main part of it, to define your filter:

app.filter('filterByCategories', function() {
    return function(input, categories) {
      // Input is the array to be filtered, categories is the list of
      // categories to filter by
      input = input || [];
      categories = categories || [];

      var output = [];
      for (var i = 0; i < input.length; i++) {
        for (var j = 0; j < categories.length; j++) {
          // If input matches any of the categories, then add it to the list
          if (input[i].categories.indexOf(categories[j].trim()) >= 0) {
            output.push(input[i]);
            break;
          }
        }
      }

      return output;
    };
  })

Then you can use the custom filter like so:

<li ng-repeat="item in data | filterByCategories: filterStr.split(',')">

Or:

<li ng-repeat="item in data | filterByCategories: ['Adventure', 'Strategy']">

来源：https://stackoverflow.com/questions/31628519/using-filter-to-create-array-then-using-that-array-to-filter-ng-options

标签

javascript