Allow joining external data using tag-transform

[fwiesweg]

Overview

In order to join per-postal-code data from a CSV file, I extended tag-transform to be able to read a row of data from a generic DataSource object and insert this data into the output tag using the new data and source elements along with two new attributes on the tag element in the output section.

Functionality

• A tag matches a regex pattern, yielding a series of matches
• A row is selected from the data source (in this case, a CSV file, but it's extendable) according to the matches
• The cells of this row are now accessible from the templates in the output tag's template

For an example, please refer to the test below: The postal_code field is matched and looked up in the CSV file (column 0). From this, a tag is generated, with its value set to "5000".

Current state

It's basically functional and does not appear to noticeably degrade performance on smaller data sets (tested on[1]) and does nothing if not configured explicitly.

If you're interested in merging this work, I'd appreciate some feedback! I'm not quite sure about formatting/indentation, ./gradlew checkstyleMain checkstyleTest does not seem to catch all issues for some reason. Docs are still missing, too.

[1] https://download.openstreetmap.fr/extracts/europe/germany/nordrhein_westfalen/munster.osm.pbf

[fwiesweg]

Seems as if my test fails on travis:

org.openstreetmap.osmosis.tagtransform.v0_6.TagTransformTest > testDataSourceTransform FAILED java.lang.AssertionError at TagTransformTest.java:100

It's green on my machine, so I guess it's some encoding issue. If someone could pass me the output files, I'll gladly fix that.

[migurski]

Hi @fwiesweg, I’d be happy to help. I’m new to helping Brett with this project. What output files would you need, and are these something you can retrieve by running Travis on a fork of this repo?

[fwiesweg]

Hi @migurski ! Thanks for the hint, didn't know it was that easy to run travis by myself. The test's green now, turned out I only had to put a version placeholder in the XML ;)

[migurski]

Thanks so much! When you have a chance, can you extend the TagTransform documentation on the wiki to reflect this new 0.48 version functionality?

[fwiesweg]

Hi, yes it's on my todo list, might take a week or two but I'll do it ;)