AX 2012: FormRun.createRecord Method with example

AX 2012: FormRun.createRecord Method with example

This post provides a tutorial about the FormRun.createRecord Method which is override able at form level for custom implementation

AudienceDynamics AX 2012 (FP, R2 R3) X++ Developers, Functional and Technical consultants and advanced users

Background

Recently I came through a scenario where I had to use a base table (supporting inheritance) as a Form data source. I needed to ensure which child table's instance is being created. Due to not being totally aware of the table inheritance implementation (and sorry for Microsoft documentation, such things are not specified anywhere) I was relying on my intelligent (or semi intelligent perhaps :D ) guesses. 

Question: Where is the InstanceRelationType field set to identify the record belonging to a child table.

Thanks to Nasheet Siddiqui | blog a close friend of mine, who guided me in the right direction. As per him, such a thing should be decided by the system at record creation method. And that is the FormRun class method: createRecord().

Example

One of the example is the PurchAgreement form, where the system decides at runtime if the agreement line is quantity based or volume based (depending on Comitment type field inrespective helper class instance). This is implemented in PurchAgreementr Form's CreateRecord method. 

createRecord() implementation at PurchAgreement form

There they have used the FormDataSource's method createType to specify exactly which child table is to be instantiated. Evaluating the commitment type member, a map is instantiated with a value pair of data source name and child table id are set. The map is then sent as parameter to 

FormDataSource > createTypes() method which takes a map in params. This method internally decides the fate of the record i.e which child table the record will belong too. Setting the instancerelationtype members are probably internal to this method.

For even better understanding of concepts, I am attaching this valuable excerpt

An excerpt from Inside Dynamics AX 2012

Traditionally, to create a record in X++ code you only had to call the FormDataSource.create method. However, that method does not let you specify the type. To support the polymorphic creation scenario, use the following method: FormRun.createRecord(str _formDataSourceName [, boolean _append = false]) All create actions performed by the kernel are routed through this method. You should use this method as well instead of the create method. The first parameter specifies the name of the form data source in which to create the record, and the second parameter contains the same append value that is passed to the create method. You can override this to put in conditional code that depends on the type being created. The call to the super of the method executes the correct logic depending on the type.

Links

• FormRun.createRecord Method [AX 2012] 
• FormDataSource.createTypes Method [AX 2012]