Some time ago I've published an article How to set programmatically
TextboxWatermark AJAX Extender
control from the Ajax Control Toolkit library. The technique described in the article has proven useful for a number of developers so when the
new release of the Ajax Control Toolkit has recently been announced
I've decided to update the article to cover some of the braking changes in Ajax Control Toolkit components.
AJAX Control Toolkit changes
One of the most significant changes in the recent Ajax Control Toolkit release that affected everything is renaming namespaces
Correspondingly the AjaxControlToolkitTextboxWrapper class that is crucial for the technique described in this article
is now called Sys.Extended.UI.TextBoxWrapper and this is a breaking change. Most if its methods haven't been renamed and
this is a good news however the new way of using the wrapper has been introduced.
Below are the code examples demonstrating how to write the code correctly with the new version of the ACT.
First we need to acquire an instance of the Sys.Extended.UI.TextBoxWrapper class for our textbox control
and this is the newly introduced technique compared to the previous version of the ACT:
var textBox = $get(textBoxId);
var wrapper = Sys.Extended.UI.TextBoxWrapper.get_Wrapper(textBox);
In the code above first I assume that the ACT is present so I don't have to check that Sys.Extended.UI
namespace is defined. Secondly the code above is safe even if the textbox is not watermarked: the get_Wrapper
static method will always return the instance of the TextBoxWrapper; the new instance will be created if the textbox is not watermarked.
Now we can set or get a value of the textbox using the instance of the TextBoxWrapper:
var oldValue = wrapper.get_Value();
In a nutshell there are two major changes introduced in the new ACT release that affect the coding technique described
here: the name of the textbox wrapper class has been changed; and now it's not required to check whether the textbox is watermarked
to use the technique above.