Monday, September 22, 2008

SysMultiTableLoookup - dynamic lookups based on multiple tables

Wow! MSDN for Microsoft Dynamics AX is getting better every day. This is terrific news!! I still remember the days, when all the information was extremely hard to find. It had its own charm though :)
Anyway, this topic is really not about MSDN. It is about lookup forms.

First of all, for the record: I (and the Best Practices document as well) recommend creating custom lookup forms in AOT instead of dynamically coding them in the overridden lookup methods on controls/datasource fields.
But, in reality, this is true only for lookup forms with very large complexity. I won't go into a discussion of why that is the way it is here. :)

Now, back to what I was planning to write about:
In order to build a lookup form from code, developers use the SysTableLookup class.
You can go to MSDN (mentioned above) to read a How-to article on creating a run-time lookup form, as well as take a quick look at the SysTableLookup method descriptions.

SysTableLookup class has evolved over the multiple releases, providing more and more flexibility and control to the application developers.
I would like to publish another extension to this class, SysMultiTableLookup, which I hope will prove useful to members of the AX community.

Short list of features:
- Backward compatible, should cover everything that is present in AX 2009 version of SysTableLookup class
- Allows including multiple tables into lookups with different join types
- Completely based on the Query that you build, no extra parameters (except for the control) are needed to initialize the class
- Allows adding aggregated fields to the lookup
- Displays fields based on Boolean Enum as check boxes
- Allows to specify alternative labels when adding fields to the lookup

New download link, as Axaptapedia seemed to mess up the file

You can download the project from axaptapedia.com.


It has (to some extent) been tested on Axapta 3.0 SP3, AX 4.0 and AX 2009.

Also included in the project is a tutorial form, showing 4 examples of dynamic lookups using the new class. After importing the project, make sure to try out the form, and use it for future reference for code examples and other inspiration.