Custom Lookup using lookupReference method in AX2012

In this article, giving an example for defining the lookup using lookupReference  method in simple way.

step 1 .

Override the lookupReference method on a required filed node in forms datasourse .


public Common lookupReference(FormReferenceControl _formReferenceControl)
{
  
    return MytableToGetLookup::getlookup(_formReferenceControl );
}

Step 2 .
Define method on table from where you have to get the values in the lookup

public static Common lookupReceiptLayout(FormReferenceControl  _ctl, SomeFilter  _someFilter)
{
    SysReferenceTableLookup sysTableLookup = SysReferenceTableLookup::newParameters(tablenum(RRPRReceiptLayout), _ctl, true);
    Query                   query = new Query();
    QueryBuildDataSource    queryBDS;
    MytableToGetLookup     _mytableToGetLookup
    ;
   
    // add the fields to show in the looup
    sysTableLookup.addLookupfield(fieldNum(MytableToGetLookup     , field1));
    sysTableLookup.addLookupfield(fieldNum(MytableToGetLookup     , field2));
   
    queryBDS = query.addDataSource(tablenum(MytableToGetLookup     )); //add datasourse
   
    queryBDS.addRange(fieldnum(MytableToGetLookup  , fieldToAddFilter)).value(_someFilter); // add filter
   
    sysTableLookup.parmQuery(query);
     _mytableToGetLookup = sysTableLookup.performFormLookup();

    return   _mytableToGetLookup ;
}

Dynamics AX will display the results of the query, based on the filter we've created. So the user will only be able to see what we want him to see, and so he'll only be able to select what we want. The problem is that if he types in an existing record in the control, even if does not get shown in our lookup, Dynamics AX will accept that.

To avoid that the user does in fact type in something we don't want, we'll have to override the validate method .