Injecting information into the rendering process of Backbone.js

Can the questions variable be passed into the view render?

I tried calling this.render inside the success function of the fetch, but I encountered an error. It seems like the 'this' keyword is not in the correct scope.

app.AppView = Backbone.View.extend({
    initialize: function(){

        var inputs = new app.Form();

        inputs.fetch({

            success: function() {

                var questions = inputs.get(0).toJSON().Questions;

                app.validate = new Validate(questions);
                app.validate.questions();

            }, // End Success()

            error: function(err){
                console.log("Error retrieving data from service: " + err);
            }

        }); // End Input.fetch()

        this.render();

    }, // End Initialize

    render: function(){
        el: $('#finder')
        var template = _.template( $("#form_template").html(), {} );
        this.$el.html(template);

    } 

Answer №1

When the success callback is triggered, it utilizes a different object compared to your View instance. To resolve this issue, consider adding the following snippet before invoking inputs.fetch:

var that = this;

Subsequently, within the success callback:

that.display();

Answer №2

If you're uncertain about your goal, and the issue lies in calling render from the success callback, there are two solutions available. You can either use Function#bind or create a self variable.

To learn more about the "self" variable, refer to var self = this?. Here's an example:

var self = this;

inputs.fetch({
    success: function () {
        self.render();
    },
    ...
});

It would be helpful to study JavaScript scopes by reading "Effective Javascript" or exploring topics like this MDN article online for better comprehension.

For Function#bind(), check out the MDN article about it. However, when using Backbone, I recommend utilizing Underscore/LoDash's _.bind instead to ensure compatibility with environments lacking support for Function#bind().

In terms of higher-level concepts, the fetching operation seems to fit better at the model or router level. Consider assigning the questions variable as the model for your view. Views are ideally not responsible for data processing or fetching; they should simply receive a model equipped with necessary methods for any required data transformations.

Views shouldn't concern themselves with the origin of the model, as this is typically managed by a router in single-page applications or through initialization code on the page.

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