ExtJS: Simple Form ignores formBind

Question

I have a tiny problem that is driving me crazy for days. I have a form panel:

Ext.define('EC.view.PasswordPanel', {
    extend: 'Ext.form.Panel',
    alias: 'widget.pwdpanel',

    bodyPadding: 15,

    initComponent: function() {
        this.initialConfig = {url:'/password/'};

        this.fieldDefaults = {
            labelAlign: 'right',
            labelWidth: 135,
            msgTarget: 'side',
            allowBlank: false,
            inputType: 'password'
        };

        //this.listeners =  {
            //// circumvent broken formBind
            //validitychange: function(comp, valid) {
                //this.down('button').setDisabled(!valid);
            //}};

        this.buttons = [{
            text: 'Change',
            formBind: true,
            scope: this,
            handler: function() {
                this.submit({
                    success: function(form, action) {
                        Ext.Msg.alert(
                            'Success',
                            '<p>Password change has been scheduled successfully.</p>' +
                                EC.DELAY_NOTICE);
                            form.reset();
                    },
                    failure: function(form, action) {
                        if ('result' in action &&
                            'msg' in action.result) {
                            Ext.Msg.alert('Error', action.result.msg);
                        }
                    }
                });
            }
        }];
        this.items = [ {
            xtype: 'textfield',
            name: 'pw_old',
            fieldLabel: 'Old password'
        }, {
            xtype: 'textfield',
            name: 'pw_new1',
            id: 'pw_new1',
            fieldLabel: 'New password',
            minLength: 8,
            maxLength: 16
        }, {
            xtype: 'textfield',
            name: 'pw_new2',
            fieldLabel: 'Confirm new password',
        } ];

        this.callParent(arguments);
    }
});

which I instantiate a tab from within a TabPanel:

{
            title: 'Change Password',
            items: { xtype: 'pwdpanel' },
},

Now, the validation works perfectly fine, but the "Change" button isn't disabled while the form isn't valid. To be clear: When I press it, it doesn't submit, yet I feel it should be disabled?

Am I doing something obvious wrong? Another form panel in a second tab works just fine.

I can circumvent the problem using the listener I commented out, but I understand that it should work w/o.

P.S. Feel free to point out any stupidities/bad style, I'm totally new to ExtJS.

Answer 1

It's clear bug of extjs because even their own example works the same.

However, I've found quick workaround - add to initComponent lines:

this.on('afterrender', function(me) {
    delete me.form._boundItems;
});

Here is fiddle.

UPDATE

The bug is fixed in 4.0.7.

Answer 2

Sure this is an extjs bug as you can found at Ext.form.Basic.getBoundItems . This function originally initiate boundItems as empty array ([]) because its start querying before the fields is rendered. So here is the fix for this bug.

//Fix formBind
    Ext.form.Basic.override({
        getBoundItems: function() {
            var boundItems = this._boundItems;
            //here is the fix
            if(this.owner.rendered) {
                if (!boundItems) {
                    boundItems = this._boundItems = Ext.create('Ext.util.MixedCollection');
                    boundItems.addAll(this.owner.query('[formBind]'));
                }
            }
            return boundItems;
        }
    });

This fix apply globally so you don't need to always add 'afterrender' handler on every form that you create. Here is the sample of use http://jsfiddle.net/gajahlemu/SY6WC/