How to write an inverse routine for an info object at field level.

Question

Hi All,
Our requirement is as follows:
Need to populate 0MAT_PLANT in a virtual provider. But during query performance it is like -
If someone were to add a filter to the BW query on 0MAT_PLANT, it would take the system awhile to search the APO database for that 18 CHAR material number because the data in APO is stored differently (40 CHARs).  The point of the  inverse routine is to convert the 18 CHAR to be 40 CHAR for those times when someone selects on 0MAT_PLANT.  That way, the field types match and finding the data in APO is much quicker.
Hence if we need selection on the selection scree of the query for 0MAT_PLANT, we are trying for inverse routine which will convert 18 chars to 40 chars in the query level and the performance will be quicker.
See, 0MAT_PLANT is of 18 Char length. We are mapping it from ZMATNR in source which is of 40 chars. Thus initially in the field routine we will write a code to convert 0MAT_PLANT to 18 from 40.
Below is the code and the place we now we also need to write inverse routine to convert it to 40 from 18 chars.
*****Code to convert from 40 chars to 18******
*In APO if the material contains all integers values the material will
* come over as a 40 byte field.  It needs to be shortened.
  IF SOURCE_FIELDS-/BIC/ZMATNR CO '0123456789'.
    short_material = SOURCE_FIELDS-/BIC/ZMATNR+22(18).
*In APO if the material contains any character fields the material will
* not be zero filled and will be left alligned. Take the 1st 18 bytes.
  ELSE.
    short_material = SOURCE_FIELDS-/BIC/ZMATNR(18).
  ENDIF.
*add leading zeros to numeric only value
  IF short_material CO '0123456789 '.
     w_num18 = short_material.
     short_material = w_num18.
  ENDIF.
  RESULT = short_material.
*$*$ end of routine -
***********here the iverse routine need to write************
*       Method invert_0MATERIAL
*       This subroutine needs to be implemented only for direct access
*       (for better performance) and for the Report/Report Interface
*       (drill through).
*       The inverse routine should transform a projection and
*       a selection for the target to a projection and a selection
*       for the source, respectively.
*       If the implementation remains empty all fields are filled and
*       all values are selected.
  METHOD invert_0MATERIAL.
*$*$ begin of inverse routine - insert your code only below this line*-*... "insert your code here
Here you would write logic in 0MAT_PLANT to do the opposite of the above,
convert 18 back to 40 characters.
*$*$ end of inverse routine - insert your code only before this line *-*
  The articulated form above in RED says that the subroutine i.e. the inverse routine is implemented for direct access and report to report interface.
Could anybody please help me or let me know any idea related to this.

Answer 1

Hi All,
Our requirement is as follows:
Need to populate 0MAT_PLANT in a virtual provider. But during query performance it is like -
If someone were to add a filter to the BW query on 0MAT_PLANT, it would take the system awhile to search the APO database for that 18 CHAR material number because the data in APO is stored differently (40 CHARs).  The point of the  inverse routine is to convert the 18 CHAR to be 40 CHAR for those times when someone selects on 0MAT_PLANT.  That way, the field types match and finding the data in APO is much quicker.
Hence if we need selection on the selection scree of the query for 0MAT_PLANT, we are trying for inverse routine which will convert 18 chars to 40 chars in the query level and the performance will be quicker.
See, 0MAT_PLANT is of 18 Char length. We are mapping it from ZMATNR in source which is of 40 chars. Thus initially in the field routine we will write a code to convert 0MAT_PLANT to 18 from 40.
Below is the code and the place we now we also need to write inverse routine to convert it to 40 from 18 chars.
*****Code to convert from 40 chars to 18******
*In APO if the material contains all integers values the material will
* come over as a 40 byte field.  It needs to be shortened.
  IF SOURCE_FIELDS-/BIC/ZMATNR CO '0123456789'.
    short_material = SOURCE_FIELDS-/BIC/ZMATNR+22(18).
*In APO if the material contains any character fields the material will
* not be zero filled and will be left alligned. Take the 1st 18 bytes.
  ELSE.
    short_material = SOURCE_FIELDS-/BIC/ZMATNR(18).
  ENDIF.
*add leading zeros to numeric only value
  IF short_material CO '0123456789 '.
     w_num18 = short_material.
     short_material = w_num18.
  ENDIF.
  RESULT = short_material.
*$*$ end of routine -
***********here the iverse routine need to write************
*       Method invert_0MATERIAL
*       This subroutine needs to be implemented only for direct access
*       (for better performance) and for the Report/Report Interface
*       (drill through).
*       The inverse routine should transform a projection and
*       a selection for the target to a projection and a selection
*       for the source, respectively.
*       If the implementation remains empty all fields are filled and
*       all values are selected.
  METHOD invert_0MATERIAL.
*$*$ begin of inverse routine - insert your code only below this line*-*... "insert your code here
Here you would write logic in 0MAT_PLANT to do the opposite of the above,
convert 18 back to 40 characters.
*$*$ end of inverse routine - insert your code only before this line *-*
  The articulated form above in RED says that the subroutine i.e. the inverse routine is implemented for direct access and report to report interface.
Could anybody please help me or let me know any idea related to this.