Why should I use GWT Deferred Binding Using Replacement

[chaitanya karthikk]

Hi all, I am new to GWT and am reading about GWT deferred binding. I understood about deferred binding a bit. It is used to generate javascript files at runtime for a browser based on the user agent.

I was reading this page. What I don't understand is why should I use GWT's "Deferred binding using replacement"?

The author says that for each specific browser an appropriate javascript file is generated. Again he says that when you are using PopupPanel you have to use GWT's <replace-with> element to generate browser specific implementations.

My question is will GWT not do it for me? Will it not identify the right implementation itself?

Or my understanding is wrong? Is the author trying to say that it is done automatically, it is already coded and he is only trying to explain deferred binding neatly by showing the code?

Thank you all in advance, have a good day.

[chaitanya karthikk]

I think my understanding is wrong. May be the author is trying to tell this is how GWT selects the specific implementation for PopupPanel at runtime based on the user agent.

[chaitanya karthikk]

What I don't understand is will GWT generate all javascript files for every browser while compiling the module or will it generate the javascript file when a request comes?

What do you say experts?