MapGuide RFC 181 - OpenLayers preview for WMS layers and development HTTP server
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 | Jul 28 2020 |
| Last Modified | 4 Aug 2020 |
| Author | Jackie Ng |
| RFC Status | adopted |
| Implementation Status | implemented |
| Proposed Milestone | 4.0 |
| Assigned PSC guide(s) | (when determined) |
| Voting History | (vote date) |
| +1 | Jackie,Reno,Gordon,Martin |
| +0 | |
| -0 | |
| -1 | |
| no vote |
Overview
This RFC proposes to add a new OpenLayers HTML viewer representation for WMS responses and a new developmental HTTP server to simplify dev/testing of the MapGuide Web Tier.
Motivation
Currently, there is no built-in previewing mechanism for WMS layers in MapGuide. Right now, to preview a WMS layer from MapGuide requires an external WMS client like QGIS or Gaia to connect to the MapGuide WMS Service.
Another tangential problem is that the development/testing of mapagent C++ code in the MapGuide Web Tier is severely hampered by the need to stand up a full-blown instance of Apache httpd or IIS in front of the mapagent binaries. Having a simple http server that integrates the mapagent handling code can rapidly improve development and iteration of mapagent functionality.
Proposed Solution
Add cpp-httplib to Oem. This is a MIT-licensed header-only C++11 library for easily implementing a HTTP web server.
Add a new MgDevHttpServer project to the WebTier solution. This project is a simple console application using cpp-httplib that sets up a mapagent for testing/development purposes. This http server should not be used as a production or public-facing http server.
Update our WMS templates to include a HTML template for WMS GetMap previews with OpenLayers.
Update our WMS implementation to support a new FORMAT of application/openlayers. If this parameter value is supplied, an OpenLayers HTML preview of the given WMS layer is rendered instead of a map image.
Add a new MgWebTestRunner project to the WebTier solution. This is a skeleton catch2-based test runner that we can expand in the future with more test cases relating to the Web Tier.
This is already implemented and ready-to-merge in the ogc_viewer_representation sandbox. Upon adoption of this RFC, it will be merged into trunk.
Implications
None. This is a new output format for an existing operation.
Test Plan
Verify GetMap requests produce an OpenLayers preview of the WMS layers if a FORMAT of application/openlayers is provided
Funding / Resources
Community
