How can I make a conditional statement like “include?” method in Ruby on Angular ng-if

Question

Sorry about the difficulty for me to make the title much clearer. I'll explain as much as I can.

I use Rails as the backend (API), and AngularJS as the frontend.

I got several article_ids that have been liked(thumb up) from articleCtrl, named $scope.article_has_liked (it's an array contains several article_ids, like [24,45,55] ), just like below, :

articleCtrl.js.coffee

$http.get(url).success((data)->
console.log(data)
$scope.articles = data.articles
$scope.topic = data.topic
$scope.article_has_liked = data.article_has_liked
)

And I pass these article_ids ($scope.article_has_liked) to the show.html, in order to use "ng-if" to conduct a judgement, just like below:

Show.html

<div ng-if="article_has_liked.include?(article.id)">
    <button class="btn btn-link" ng-click="likeItOrNot(article.id, topic.id)">
    <span class="glyphicon glyphicon-star"></span>
    </button>
</div>
<div ng-if="article_has_liked.exclude?(article.id)">
    <button class="btn btn-link" ng-click="likeItOrNot(article.id, topic.id)">
    <span class="glyphicon glyphicon-star-empty"></span>
    </button>
</div>

Here comes the problem !

I'd like to use .include? method in Ruby to determine if the article.id is included by the article_ids that have been liked . If it is liked, I'll give it a solid star. But I found that the Angular seems not to accept the usage, and it returned the error just like below:

Error: Syntax Error: Token 'undefined' expected : at column NaN of the expression [article_has_liked.include?(article.id)] starting at [article_has_liked.include?(article.id)].
throwError@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:6672:1
ternary@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:6827:9
_assignment@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:6800:16
expression@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:6796:12
_filterChain@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:6762:16
statements@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:6742:25
parser@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:6661:13
$ParseProvider/this.$get</<@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:7282:1
compileToFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:9215:16
$RootScopeProvider/this.$get</Scope.prototype.$watch@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:8547:19
ngIfDirective</<.compile/<@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:14677:9
nodeLinkFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:4960:13
compositeLinkFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:4539:15
compositeLinkFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:4554:13
compositeLinkFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:4554:13
compositeLinkFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:4554:13
compositeLinkFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:4554:13
compositeLinkFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:4554:13
publicLinkFn@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:4456:30
ngRepeatAction@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:15463:15
$watchCollectionAction@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:8718:11
$RootScopeProvider/this.$get</Scope.prototype.$digest@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:8812:21
$RootScopeProvider/this.$get</Scope.prototype.$apply@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:9013:13
done@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:10266:34
completeRequest@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:10450:7
createHttpBackend/</xhr.onreadystatechange@http://localhost:3000/assets/angular.self-cdfe10db265380c82ec938d307fce2720dc9fb9d8cfa21c78928031af124e282.js?body=1:10405:1
 <!-- ngIf: article_has_liked.include?(article.id) -->

So I want to ask if there is any conditional statement which has similar meaning to .include? that I can use in AngularJS "ng-if", or there is any better way for me to conduct this judgement?

Thanks everyone for helping me this confusing question!

Answer 1

ng-if="article_has_liked.include?(article.id)"

更新为此：

ng-if="article_has_liked.include?(article.id):false value here"

Answer 2

That is a JavaScript relating question, not AngularJS. But may that answer your question:

Often you will need to check whether an array contains a certain item. You can do this by using the indexOf() method. If the code does not find the item in the list, it returns a -1 .

var article_has_liked = [24,45,55];
if(article_has_liked.indexOf(99) == -1){
 alert("data not found");
}

Not sure but you can try something:

<div ng-if="article_has_liked.indexOf(article.id) != -1"> 

Note: This above condition is to check for include. If it include your article.id in article_has_liked then only execute that block. If you want to check exclude then you can simply use == instead != I hope it works for you.