How to use/link external api to show the fetched data in the grapejs component

I am new to grape and backbonejs.I want to make a template builder which apart from having default components provided by grapejs like the label, image etc will also have custom components for ex - Top 5 products today having an image and product name and it will get the fresh data from the server. In this scenario I am not able to figure out where should I make the API call and how can I use the fetched results to show in components. Link to the code which I have tried is in the comments.

if you move your code to your prop change handler, instead of the onRender function of the view you will be able to use the values from the API call as you want.

Check this small change: https://jsfiddle.net/jvas28/8sb3tn94/1/

const editor = grapesjs.init({
    container: '#gjs',
  fromElement: 1,
  height: '100%',
  storageManager: { type: 0 },
});


editor.DomComponents.addType('test-component', {
    model: {
        defaults: {
            testprop: '12345',
            url: 'https://jsonplaceholder.typicode.com/posts/1'
        },
        init() {
            console.log('Local hook: model.init', this.attributes.testprop);
            fetch(this.attributes.url)
                .then(response => response.json())
                .then(commits => {
                    this.set('testprop', 'Test');
                    console.log(this.attributes.testprop);
                });
            this.listenTo(this, 'change:testprop', this.handlePropChange);
            // Here we can listen global hooks with editor.on('...')
        },
        updated(property, value, prevValue) {
            console.log('Local hook: model.updated',
                'property', property, 'value', value, 'prevValue', prevValue);
        },
        removed() {
            console.log('Local hook: model.removed');
        },
        handlePropChange() {
             let prop = this.get('testprop');
            // Here inside view it is getting the old value. of "testprop" i.e '12345' but not 
            //the new value 
            //which is being fetched from server in the init() of model.
            let comp1 = '<div>' +
                '<img src="https://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Image_created_with_a_mobile_phone.png/1200px-Image_created_with_a_mobile_phone.png" />' +
                '<span title="foo">' + prop + '</span>' +  '</div>';

                const component = editor.addComponents(comp1);
            return component
        }
    },
    view: {
        init() {
            console.log('Local hook: view.init');
        },
       
    },
});

// A block for the custom component
editor.BlockManager.add('test-component', {
    label: 'Test Component',
    content: `<div data-gjs-type="test-component"></div>`,
});