ArcGIS Pro to GeoServer

Use Case

As part of the Open Data initiative, the swiss canton Aargau wishes to publish geodata as Open WMS by using GeoServer ¹. In the administration of this canton, geodata is managed decentrally, within the individual offices of the administration. For data entry and styling, ArcGIS Pro is a well established tool in these offices. As the data management and styling languages of ArcGIS Pro and GeoServer are quite different, this raises the question of how to publish the geodata in an automated pipeline and with a styling as close as possible to the data owner’s selection in ArcGIS Pro. In this context, Camptocamp is consulting canton Aargau and improving open source software for this purpose where needed. This article will focus on the styling aspect, where additional development of open source software was necessary. 

Converting ArcGIS Pro styling to GeoServer: 
the problem

The goal of the process is the conversion from ArcGIS Pro styling (native format: .lyrx) to SLD. Several existing open source software projects were evaluated. The tools SLYR², MapQonverter^3,4 and Geocat bridge⁵ work for the traditional ESRI ArcMap, but not for its successor ArcGIS Pro, they do not support the Lyrx format. The QGIS plugin qlyrx⁶ can process lyrx styles, and convert them to QGIS styling. This is promising for environments where QGIS is actively used, especially when migrating from ArcGIS Pro to QGIS is the goal. As canton Aargau has no plans of using QGIS, this approach is not the best suited in this case. An alternative could be to enhance the related library lyrxtoqml⁷, which outputs QGIS symbology exclusively, to be able to output other formats as well. The maturity of this library is unclear however, and the project has had no activity recently.

Converting ArcGIS Pro styling to GeoServer:
the solution

We enhanced the open source project “bridge-style”⁸ to cover more aspects of the lyrx format and of the use cases existing at canton Aargau. The bridge-style is a Python library which can interpret the ArcGIS Pro Lyrx format, convert it to GeoStyler⁹, and then, from this representation, can write as output format all formats supported by GeoStyler. Improvements done to the library were:

• be able to use the library as a command-line tool, so that it can be integrated in automated processing at canton Aargau
• add parameters to the tool, with options to convert layer names to lowercase (ArcGIS Pro is case insensitive, but GeoServer is not), and to convert elements using ESRI fonts to placeholders for development environments which do not have ESRI font libraries;
• support font family and font halo
• support non-ascii texts