MapGuide RFC 50 - Enhance expression engine concat function

This page contains a change request (RFC) for the MapGuide Open Source project. More MapGuide RFCs can be found on the RFCs page.

Status

RFC Template Version	(1.0)
Submission Date	June 25, 2008
Last Modified	Bruce Dechant Timestamp
Author	Bruce Dechant
RFC Status	draft
Implementation Status	draft
Proposed Milestone	2.1
Assigned PSC guide(s)	Bruce Dechant
Voting History
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+0
-0
-1

Overview

This RFC is for adding an additional syntax to the concat function of the expression engine.

Motivation

The existing concat function syntax is difficult to work with when multiple concatenations need to be done. It requires the concat functions be nested whenever a new item needs to be concatenated.

Proposed Solution

The proposed solution is to add support for an additional syntax to the concat function.

Old syntax:

concat('Parcel ID: ', concat( PID , concat('\nOwner Name: ', concat(NullValue (  OWNER_NAME , '' ) , concat('\nAddress: ',  SITE_ADDR )))))

New syntax:

concat('Parcel ID: ', PID , '\nOwner Name: ', NullValue (  OWNER_NAME , '' ) , '\nAddress: ', SITE_ADDR )

The new syntax will consist of a comma delimited list of concatenation items.

Implications

The existing concat function syntax will continue to be supported in addition to the new syntax.

Test Plan

Test that the existing and new concat function syntax work.

Funding/Resources

None at this time.