Ext.extend vs Ext.override?

Question

What is the difference between Ext.extend and Ext.override? In java, you extend a class and you override its methods. But looking at syntax, it seems in extjs, you can both extend a class and override a class

score 36 · Accepted Answer · answered Feb 04 '11 at 19:20

36

Ext.extend gives you a new class basing on existing one.

Ext.override modifies existing class without creating a new one.

It's not something specific to ExtJS. It's how JavaScript's prototype-based object model works. It's quite different from what you're used to in Java. ExtJS just adds these two utility methods to make it a bit easier to use.

answered Feb 04 '11 at 19:20

Mchl

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So Ext.override has no equivalent in java? – Victor Feb 04 '11 at 19:21
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this is not entirely true, you can override methods any existing class when you create an instance of it as an anonymous inner class. `ArrayList al = new ArrayList() { public void add(Object o) { // override }` for example. This is the same thing in spirit since it is still an `ArrayList` as far as any client is concerned. – Nov 11 '14 at 15:54
@JarrodRoberson: Interesting! I've very little experience with Java, so I didn't know this. Thanks! – Mchl Nov 12 '14 at 08:35

score 1 · Answer 2 · answered May 05 '14 at 10:18

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Mchl has already answered to your query.

I just want to add, for adding features to ExtJs involves these four ways:

Extend
Override
Plugin
Sequence/Intercept

Please refer to this link for detail information:

http://www.slideshare.net/VinylFox/four-ways-to-add-features-to-ext-js

answered May 05 '14 at 10:18

Kunal Goel

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In ExtJS 5 we have `Ext.Function.interceptBefore` instead Intercept and `Ext.Function.interceptAfter` instead Sequence. – rzymek Aug 27 '14 at 17:10
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Thanks for adding up the information, I didn't looked @ExtJs 5 that time. – Kunal Goel Nov 13 '14 at 12:24

Ext.extend vs Ext.override?

2 Answers2