$ListImg

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Revision as of 20:49, 5 June 2018 by JAL (talk | contribs) (misc cleanup)
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Associate an image with a $list

Note: Many $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $ListImg function is BindImage.

The $ListImg function accepts two arguments and returns a numeric result: a 0 (indicating that the image has been associated with the $list) or a negative number (indicating that an error has occurred). It is a callable $function.


Syntax

[%result =] $ListImg(list_identifier, image_id)

%result A string that contains a 0, or it contains a negative number if an error has occurred.
list_identifier A $list identifier. This is a required argument.
image_id A string containing the name of an image, or it can be any image item from the required image. This is a required argument.

Return codes

-5 - Required argument not specified -6 - $List identifier invalid -8 - Image not found

Usage notes

  • Suppose there is an image with the following description:

    IMAGE SALES ITEM IS STRING LEN 16 ID IS STRING LEN 8 PRICE IS BINARY LEN 4 END IMAGE

    One can associate this image with the $list %list with:

    %rc = $ListImg(%list, 'SALES')

    or

    %rc = $ListImg(%list, %SALES:ID)

    While the latter is syntactically inefficient (:ID is superfluous), it is more efficient because the image name hashing and lookup is done at compile time rather than evaluation time.

  • Functions that can use the association between an image and a $list are:
  • The association between an image and a $list is an association between the image and the particular $list identifier value. A $ListMove does not change the image association of the target $list, and the image association of a $list is not saved or restored with $ListSav and $ListRst.

Products authorizing $ListImg