ExtJS Interview Questions and Answers
Freshers / Beginner level questions & answers
Ques 1. Why do we need javascript Library?
Javascript is an awesome, super flexible language. Browsers are the modern UI paradigm.
The javascript Libraries now must provide a rich set of UI Widgets.
javascript libraries:
* JQuery
* Qooxdoo
* Dojo
* Prototype.js
* Mootools
* ExtJS
Ques 2. Why did you choose Ext JS?
The overall design of ExtJS is exemplary.One can learn a lot from it’s unified architecture – no matter which language one is programming in.
Extjs requires you to start with one of their base classes – ensuring a consitent model. Consistency is extremely important for the library to be reusable.
a.Extjs documentation seems to be very comprehensive and well maintained.
b.key aspect of the EXTJS Library is the cross-browser support.
c.Build rich Internet applications with Ext JS
d. Ext JS framework is the multitude of rich UI elements provided. These elements include forms, dialog boxes, tabs, trees, and grids.
e.The Ext JS framework includes support for Ajax implementations.
f.Ext JS integration with other Web server frameworks.
g.Ext JS framework development into several popular integrated development environments (IDEs), including Eclipse, Aptana, and Komodo.
h.Ext JS provides excellent performance.The framework is fully object oriented and extensible. Because it's written in the JavaScript language
Ques 3. Integration of Web development server-side frameworks with Ext JS?
You can use Ext JS with other common Web development server-side frameworks, including PHP, the Java™ language, Microsoft® .NET, Ruby on Rails, and ColdFusion.
Ques 4. How to access DOM element using EXTJS?
The Element API is fundamental to the entire Ext library.
Using traditional Javascript, selecting a DOM node by ID is done like this:
var myDiv = document.getElementById('myDiv');
Using Extjs:
Ext.onReady(function() {
var myDiv = Ext.get('myDiv');
});
Ques 5. What is syntax for Extjs Button click event?
Ext.onReady(function() {
Ext.get('myButton').on('click', function(){
alert("You clicked the button");
});
});
Ques 6. What is use of Ext.onReady() function ?
Ext.onReady is probably the first method that you’ll use on every page. This method is automatically called once the DOM is fully loaded, guaranteeing that any page elements that you may want to reference will be available when the script runs.
syntax:
Ext.onReady(function() {
alert(“Congratulations! You have Ext configured correctly!”);
});
Ques 7. List out the extjs library files to include in JSP page?
ext-base.js
ext-all-debug.js or ext-all.js
ext-all.css
base.css or examples.css
Ques 8. List out the css file required to apply Extjs Theme property?
xtheme-gray.css
ext-all.css
Ques 9. What is purpose of MessageBox?
MessageBox is asynchronous.
MessageBox call, which demonstrates the readable message to user.
MessageBox used for multiple purpose like
Ext.Msg.alert()
Ext.Msg.prompt()
Ext.Msg.show({});
Ext.Msg.wait();
Ques 10. Write syntax for MessageBox show() method?
Ext.MessageBox.show({
title: 'Paragraph Clicked',
msg: 'User clicked on Paragraph',
width:400,
buttons: Ext.MessageBox.OK,
animEl: paragraph
});
Ques 11. What is method to Update the message box body text for MessageBox?
updateText( [String text] ) : Ext.MessageBox
Ques 12. What is a widget?
A widget is a tiny piece or component of functionality.
Ques 13. How to find no of records in a store?
Using
store.getTotalCount() : Gets the total number of records in the dataset as returned by the server.
Ques 14. How to handle updates for store changes?
Use store.commitChanges()
Ques 15. How to get record using id?
store.getById( String id ) : Get the Record with the specified id.
Ques 16. What is the purpose of load() in store?
store.load() : returns boolean
Loads the Record cache from the configured Proxy using the configured Reader.
For remote data sources, loading is asynchronous, and this call will return before the new data has been loaded.
store.load({callback: fnCheckData, scope: this});
Ques 17. How many types of layout managers exist in extjs?what are they?
Layouts fall under this package Ext.layout.*
Types of layouts:
Absolute Layout:
This is a simple layout style that allows you to position items within a container using CSS-style absolute positioning via XY coordinates.
Accordion Layout:
Displays one panel at a time in a stacked layout. No special config properties are required other than the layout.
All panels added to the container will be converted to accordion panels.
AnchorLayout:
This type of layout is most commonly seen within FormPanels (or any container with a FormLayout) where fields are sized relative to the container without hard-coding their dimensions.
BorderLayout:
Border layouts can be nested with just about any level of complexity that you might need.
Every border layout must at least have a center region. All other regions are optional.
CardLayout (TabPanel):
The TabPanel component is an excellent example of a sophisticated card layout. Each tab is just a panel managed by the card layout such that only one is visible at a time
CardLayout (Wizard):
You can use a CardLayout to create your own custom wizard-style screen.
FitLayout:
A very simple layout that simply fills the container with a single panel.
FormLayout:
FormLayout has specific logic to deal with form fields, labels, etc.FormLayout in a standard panel,
ColumnLayout:
This is a useful layout style when you need multiple columns that can have varying content height.Any fixed-width column widths are calculated first, then any percentage-width columns specified using the columnWidth config
TableLayout:
Outputs a standard HTML table as the layout container.you want to allow the contents to flow naturally based on standard browser table layout rules.
Ques 18. What is xtype?
The xtype will be looked up at render time up to determine what type of child Component like TextField, NumberField etc to create. i,e
xtype = Class
----------------------
button = Ext.Button
textfield = Ext.form.TextField
radio - Ext.form.Radio
grid = Ext.grid.GridPanel
combo = Ext.form.Combobox
toolbar = Ext.Toolbar
Ques 19. How to get record object from store?
var record = grid.getStore().getAt(rowIndex);
Ques 20. How to stop editing a record?
newRecord.endEdit();
Ques 21. How to start editing a record?
newRecord.beginEdit();
Ques 22. How to commit a record modification?
newRecord.commit();
Ques 23. How to get a value of textfield or combo box?
using getvalue();
var selectedValue = mytextfield.getValue();
Ques 24. How to apply css on select of combo box?
Using config option as
emptyClass : 'emptycss', where emptycss is a css classname
Ques 25. What are components required for grid panel?
store, columnmodel, id, width,height
46. how to disable menu option for header in columnModel?
using menuDisabled: true
Ques 26. How to hide the column in grid panel?
using hidden : true
Ques 27. How to write extjs decode()?
var json = Ext.decode(response.responseText);
Ext.Msg.alert('Error', json.error);
Most helpful rated by users:
- Why did you choose Ext JS?
- Why do we need javascript Library?
- What is syntax for Extjs Button click event?
- How to access DOM element using EXTJS?
- Integration of Web development server-side frameworks with Ext JS?
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