MS RFC 47: Move IGNORE_MISSING_DATA to run-time configuration

Date

2008/10/09

Author

Paul Ramsey

Contact

pramsey at cleverelephant.ca

Last Edited

2008/10/15

Status

Adopted on 2008-10-15 - Completed

Version

MapServer 5.4

Overview

Making the options for ignoring missing data in tile-indexed layers and WMS client layers more flexible, and configurable at run-time via the map file.

Technical Solution

Currently MapServer has only compile-time (./configure –ignore-missing-data) control of behavior when files referenced in tile indexes are missing, via the IGNORE_MISSING_DATA define, and that behavior is applied globally.

Under this RFC, the missing data behavior will be defined:

  • at run time

  • globally for a map file

As well, the option to „fail on a missing layer“ will be added to the WMS client code, which currently defaults to „ignore on a missing layer“.

All changes will preserve the current default behavior in cases where new behavior is not requested by the user: missing data in tileindexes will continue to cause failure and missing WMS layers will continue to be ignored, unless MapServer is compiled with –ignore-missing-data.

A map-level configuration option will be added, CONFIG „ON_MISSING_DATA“ „[ACTION]“, with the following valid actions: „IGNORE“, „LOG“, „FAIL“. The default map-level behavior will be „FAIL“, unless MapServer is compiled with –ignore-missing-data, in which case it will be „LOG“. This will preserve the current behavior for all legacy mapfiles and compile set-ups.

In the case of „LOG“ behavior, the logging will only occur if the mapfile is set up for logging: DEBUG is set and MS_ERRORFILE is set. Documentation must note that DEBUG and MS_ERRORFILE need to be set.

At the same time, this ticket (#2722) can probably be tracked down and resolved.

Mapscript Implications

None.

Files Affected

mapshape.c
mapogr.c
mapraster.c
maprasterquery.c
  • Documentation will be updated to reflect the new feature

    • MapServer Mapfile Reference

Backwards Compatibility Issues

None. Legacy mapfiles and compile setups should retain existing behavior in the presence of this new code.

Voting History

N/A

References

N/A