When trying to find a trailing comma error in JavaScript/JSON (mostly for Internet Explorer) regular expressions come in nicely. Search for the following:
,\s+}
It matches a comma followed by one or more whitespaces (tabs, spaces, line breaks), followed by a closing bracket.
It will not match the following (of course):
{
property1: '123',
property2: '456',
//property3: '789'
}
But still, it’s a nice way of quickly searching for trailing comma errors.
Having a ‘method.$previous is undefined’ error in ExtJS 4? You’re probably calling ‘callOverridden‘ instead of ‘callParent‘ when extending a class.
Ext.define('MyApp.controller.BaseController', {
extend: 'Ext.app.Controller',
myFunction: function() {
console.log('myFunction in BaseController');
}
});
Ext.define('MyApp.controller.SpecificController', {
extend: 'MyApp.controller.BaseController',
myFunction: function() {
this.callOverridden(arguments);
console.log('myFunction in SpecificController');
}
});
This will show a “method.$previous is undefined” in the console. Function ‘callOverridden’ should be used when explicitly overriding a function using ‘override’:
MyApp.controller.BaseController.override({
myFunction: function() {
console.log('myFunction overridden');
this.callOverridden(arguments);
}
});
What should be used in the first example is:
Ext.define('MyApp.controller.SpecificController', {
extend: 'MyApp.controller.BaseController',
myFunction: function() {
this.callParent(arguments);
console.log('myFunction in SpecificController');
}
});
I’m currently in the process of converting a ExtJS 3 application to ExtJS 4. One of the things ExtJS 3 couldn’t do is submit the value of an unchecked checkbox. Checkboxes only have a value when they are checked.
Two situations where it’s nice to send an unchecked value to the server:
XCheckbox written by Jsakalos did a nice job for older versions of ExtJS.
In ExtJS 4 you can use the checkbox provided by the framework, just make sure you set the ‘uncheckedValue‘ property.
Example:
Ext.define('App.view.CheckTest', {
extend: 'Ext.form.Panel',
alias: 'widget.checktest',
buttons: [{
text: 'Submit',
handler: function(button, event) {
var form = button.up('form').getForm();
form.submit();
}
}],
defaultType: 'checkbox',
items: [{
boxLabel: 'Agree with TOS',
inputValue: 'true',
name: 'agreeTOS',
uncheckedValue: 'false'
}],
title: 'Terms of service agreement',
url: '/submitURL'
});
When leaving the checkbox unchecked it will submit “false”.