Extjs6.2 Modern toolkit- Extend a textbox

Question

I am still learning EXTJs and one of the thing I was trying to to was extend a component. Below is my example:

Ext.define('MyApp.view.CustomTextField',{
extend: 'Ext.field.Text',
xtype: 'customtextfield',

config:
{
    fieldID: null,
    langID: null
},
initialize: function() {
    alert("init"); //1. called before I navigate to view
     Call a controller method here
    this.callParent(arguments);
},
initComponent: function () {
    alert("initComp"); //2. not called at all
    Call a controller method here
    this.callParent(arguments);

} 

I want to call a controller method to validate if user has permission to see this field and accordingly do next actions. I want this validation to happen when I navigate to the view
I used this custom field in my View as:

xtype: 'fieldset',
        margin: 10,
        bind: '{workOrders}',
        title: 'Dispatch Information',
        items: [
            {   
                id: 'Tag',
                xtype: 'customtextfield',
                name: 'Tag',
                label: 'Tag',
                bind: '{Tag}',
                labelAlign: 'top'
            },

But the initComponent is never fired. The initialize is fired to soon ,even before my stores are loaded. How do I properly extend this control?

Answer 1

In ExtJS 6 modern there is no initComponent event for textfield . initComponent event have in classic for textfield.

For calling events in controller you need to create controller and define to you view.

In this FIDDLE, I have created a demo using form, ViewController, textfield and ViewModel. I hope this will help/guide you to achieve your requirements.

For more details please refer ExtJS Docs.

CODE SNIPPET

Ext.application({
    name: 'Fiddle',

    launch: function () {

        //Define the cutsometext from extending {Ext.field.Text}
        Ext.define('CustomText', {
            extend: 'Ext.field.Text',
            xtype: 'customtext',
            labelAlign: 'top',
            listeners: {
                initialize: 'onInitializeCutsomText'
            }
        });

        Ext.define('FormModel', {
            extend: 'Ext.app.ViewModel',
            alias: 'viewmodel.formmodel',

            data: {
                user: {
                    firstName: 'Narendra',
                    lastName: 'Jadhav',
                    email: 'narendrajadhav105@gmail.com'
                },
                permissionCng: {
                    firstName: false,
                    lastName: false,
                    email: true,
                    isAdmin: false
                }
            }

        });
        //Define the FormController from extending {Ext.app.ViewController}
        Ext.define('FormController', {
            extend: 'Ext.app.ViewController',
            alias: 'controller.formctn',

            onInitializeCutsomText: function (textfield) {
                var permissionCng = this.getViewModel().get('permissionCng');
                // Here is just basic example for disabled textfield on initialize event.
                //In your case you can put your requirement.
                textfield.setDisabled(permissionCng[textfield.getName()]);
            }
        });

        //Creating form
        Ext.create('Ext.form.Panel', {
            fullscreen: true,
            viewModel: {
                type: 'formmodel'
            },
            controller: 'formctn',
            items: [{
                xtype: 'fieldset',
                title: 'Personal Info',
                defaults: {
                    xtype: 'customtext' //Here I am using {customtext}
                },
                items: [{
                    label: 'First Name',
                    name: 'firstName',
                    bind: {
                        value: '{user.firstName}',
                        //You can also use like property
                        //hidden:'{permissionCng.firstName}'
                    }
                }, {
                    label: 'Last Name',
                    name: 'lastName',
                    bind: {
                        value: '{user.lastName}',
                        //You can also use like property
                        //hidden:'{permissionCng.firstName}'
                    }
                }, {
                    label: 'Email Id',
                    name: 'email',
                    bind: {
                        value: '{user.email}',
                        //You can also use like property
                        //hidden:'{permissionCng.firstName}'
                    }
                }, {
                    label: 'Admin Name',
                    name: 'isAdmin',
                    bind: {
                        value: '{user.isAdmin}',
                        //You can also use like property
                        hidden: '{!permissionCng.isAdmin}'
                    }
                }]
            }]
        });
    }
});