V4.0 Dynamic Action - Problem with implementing disabling/enabling button

Question

I'm having trouble implementing the following APEX V4.0 dynamic action:
The enabling/disabling of a button when a text field is not-null/null.
I'm following the example in Oracle's Advanced APEX course notes Pgs 5-13 to 5-16. I can get it working with no problems using two text fields. The example states that the "Select Type" for the button is a DOM object and you then have to enter it's name in "DOM Object" attribute. The example uses a "CREATE" button in a region position. Is "CREATE" just the Name attribute of the object? Is that what we are suppose to enter here? Also my FIND button is a "button among the region items" and not a "button in a region position" as in the example. The name of the button is P1_PAT_TBRN_SEARCH but when I use it as the Dom Object, nothing happens. Also I am using the "Key release" event for the text field that must be not-null.
I notice that Demitri Gielis on his blog couldn't get it working either (see last paragraph)
http://dgielis.blogspot.com/2010/01/apex-40-dynamic-actions-part-1.html
Any suggestions?
thanks in advance
Paul P
Edited by: PaulP on Jun 2, 2011 12:01 PM

Answer 1

Hi Paul
Two separate situtations here:
- html buttons
- template based buttons, typically comprising multiple html elements
HTML Buttons
These should be easy to enable/disable using dynamic actions, specifying an appropriate DOM selector.
Typically you would use the ID attribute of the button, so that's straight forward except for one catch..
APEX supports a #BUTTON_ID# template substitution tag , but performs substitutions only for buttons in Region positions and not for button items.
Use button attributes instead to assign a specific ID.
Template Buttons
Since these are made up of multiple elements, you need to treat them as a single object to be able to interact with them easily.
APEX provides the apex.widget.initPageItem method to integrate plugins with the dynamic actions framework:
apex.widget.initPageItem("P1_MY_ITEM", {
enable: function(){},
disable: function(){},
getValue: function(){},
setValue: function(){},
nullValue: "%null%"
});This provides you with a mechanism to over-ride one or all of these built-in methods with your own JS, to use custom code to enable/disable your template buttons.
For an example on how this works, look in the uncompressed apex_widget_4_0.js file, search for the shuttle widget.
You could just add code to initialize your template buttons manually, or better still create a plugin button to add the code automatically.
This is reasonably advanced work to do, but you really have to take your hat of to the APEX team for providing the mechanism to do it.
Regards
Mark
demo: http://apex.oracle.com/pls/otn/f?p=200801 |
blog: http://oracleinsights.blogspot.com |
book: Oracle Application Express 4.0 with Ext JS