CODEWITHSUNDEEP
javascriptbackbone.js
Rich Flavell
Rich Flavell

Reputation: 436

JavaScript object variable undefined at run-time, but is accessible

I've encountered a little bit of strange behavior with JavaScript whilst trying to get access to an object variable that does exist but not at run-time.

The following shows the initiation of the object which I'm trying to access:

app.examView = new app.ExamView({el: $("#main_wrap"), model: model});

Here is the definition and the call to the object creation where I'm trying to get access to the app.examView variable.

app.ExamView = Backbone.View.extend({
    initialize: function(){  
        this.render();  
        this.calculatorView = new app.ExamCalculatorView({el: $("#exam_calculator_container"), model: this.model});   
        this.questionView = new app.ExamQuestionView({el: $("#exam_question"), model: this.model});

Logging the examView variable here returns undefined:

var app = app || {};

app.ExamQuestionView = Backbone.View.extend({
    initialize: function(){
        console.log(app.examView);

Although, the object is accessible via the console: Firebug console

Any help would be greatly appreciated.

Upvotes: 0

Views: 93

Answers (2)

Rich Flavell
Rich Flavell

Reputation: 436

Turns out that the code that was responsible was:

app.ExamAnswerView = Backbone.View.extend({
    initialize: function() { 
        ...
    },

app.examView will not be accessible until initialize has finished executing.

Using a timeout to wait until the function has finished executing, solved the problem.

setTimeout(function() {
    app.examView.calculatorView.refresh();
}, 100);

Using a delay isn't preferred, but it's now giving access to the variable.

Seems using promises would be handy here!

Upvotes: 0

Pete TNT
Pete TNT

Reputation: 8403

I'd assume that your Backbone View is getting it's render() called before DOM is ready. Is your code wrapped in $(document).ready()?

The "strange behavior" is because the element becomes available after the DOM has been finalized.

Upvotes: 1

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