Add JSON and YAML C library dependency

[cwhite911]

Discussed in #3019

^{Originally posted by cwhite911 June 5, 2023}
In an effort add additional output data formats to modules (e.g., r.report, r.info, etc..) we are discussing adding new library dependencies to aid in JSON and YAML encoding.

Please share your feedback on the following candidate dependencies.

JSON

parson
https://github.com/kgabis/parson/
Current release: 1.5.2 (2023)

Parson is a lightweight json library written in C.

• Linux
• Windows
• Mac OSX

YAML

libyaml
https://github.com/yaml/libyaml
Current release: 1.2.2 (2021-10-01)

LibYAML is a YAML parser and emitter library.

• Linux
• Windows
• Mac OSX

Related Issues and PRs

• r.kappa: Add JSON output option #2666
• g.mapsets: Add JSON output #2542
• modules: Add JSON output for db.univar and v.db.univar #2386
• t.rast.list: Add CSV, JSON, YAML outputs #2258
• v.db.select: Add -e flag (escape newlines and backslashes) and -j flag (JSON output) #476
• r.report: JSON output #3033

Candidate Modules

Which modules should have JSON & YAML output support?

General

• g.mapsets g.mapsets: Add JSON output #2542
• g.region (GSoC) g.region: add JSON support #3941
• g.proj (GSoC) g.proj: add JSON support #4104
• g.mapset
• g.list
• g.version
• etc..

Raster

• r.univar (GSoC) r.univar: add JSON support #3783
• r.report r.report: JSON output #3033
• r.info (GSoC) r.info: Add JSON output #3744
• r.kappa r.kappa: Add JSON output option #2666
• r.horizon r.horizon: always include distance output in JSON output #3768
• r.what (GSoc) r.what: Add JSON output #3528
• r.profile (GSoC) r.profile: add JSON support #3872
• r.category (GSoC) r.category: add JSON support #4018
• r.object.geometry (GSoC) r.object.geometry: add json support #4105
• r.stats (GSoC) r.stats: add JSON output #3884
• r.colors.out r.colors.out: Add JSON support #4555
• r.describe (GSoC)
• r.coin
• r.volume
• etc..

3d Raster

• etc..

Vector

• v.info (GSoC) v.info: add JSON support #3755
• v.univar (GSoC) v.univar: add JSON support #3784
• v.db.select v.db.select: Add -e flag (escape newlines and backslashes) and -j flag (JSON output) #476
• v.db.univar modules: Add JSON output for db.univar and v.db.univar #2386
• v.to.db (GSoC) v.to.db: add JSON support #4036
• v.distance (GSoC) v.distance: add JSON support #3942
• v.category (GSoC) v.category: add JSON support #4020
• v.report (GSoC)
• v.colors.out
• etc..

Database

• db.univar modules: Add JSON output for db.univar and v.db.univar #2386
• db.describe (GSoC) db.describe: fix illegal memory access report #4202
• etc..

JSON output support without a library

• v.db.select v.db.select: Add -e flag (escape newlines and backslashes) and -j flag (JSON output) #476
• r.kappa r.kappa: Add JSON output option #2666
• g.mapsets g.mapsets: Add JSON output #2542
• r.geomorphon
• [ ]

[florisvdh]

Adding here that the preferred JSON encoding for g.proj output would be the PROJJSON specification: https://proj.org/en/latest/specifications/projjson.html. It's a JSON encoding of WKT2:2019.

[nilason]

@cwhite911 could this be closed?

[cwhite911]

@cwhite911 could this be closed?

@nilason I'm still using this issue to track all the work getting done implementing json outputs. I'm happy to close this issue and move this somewhere else if you have a good suggestion.

[wenzeslaus]

The original issue was solved. Let's create a new issue or I can create a project.

[cwhite911]

A project would be nice to keep track of this.

[NishantBansal2003]

Hey @cwhite911 @wenzeslaus , has JSON support been added to all the required modules, or are there still some modules left that need JSON support? If so, please let me know—I would love to contribute in this area!

[wenzeslaus]

Project to track it created a couple days ago: https://github.com/orgs/OSGeo/projects/10

[cwhite911]

@NishantBansal2003 any of the above tools that do not have an associated PR would be good to include. I also have some schema improvements in mind for some of the existing json enabled modules that I can make issues for.

[NishantBansal2003]

@NishantBansal2003 any of the above tools that do not have an associated PR would be good to include. I also have some schema improvements in mind for some of the existing json enabled modules that I can make issues for.

Sure, I’ll look into this. Meanwhile, could you create issues for some schema improvements in the existing JSON-enabled modules? I’ll review them and work on the fixes. Thanks

[wenzeslaus]

I don't have the analysis for the schema. I wish. From my perspective, that's up for grabs if you feel like it. I noticed that r.univar always outputs a list of objects, but for one input, it seems to me it should output a single object. That's a one clear issue I noticed.

[echoix]

I don't have the analysis for the schema. I wish. From my perspective, that's up for grabs if you feel like it. I noticed that r.univar always outputs a list of objects, but for one input, it seems to me it should output a single object. That's a one clear issue I noticed.

From a data parsing point of view, as json would be targeted around tool usage, it would be a nightmare to use if the schema/outputted format changed shape depending on the number of inputs. If it can be one or more, the. It should always be a list, and even empty if there is nothing.

[NishantBansal2003]

Hi @wenzeslaus and @cwhite911! It looks like v.colors.out currently doesn’t support JSON output. Do we want the JSON output format to match the format used in the JSON output of r.colors.out?

Would you prefer that I open an issue for discussion first, or should I go ahead and create a PR?

[petrasovaa]

Hi @wenzeslaus and @cwhite911! It looks like v.colors.out currently doesn’t support JSON output. Do we want the JSON output format to match the format used in the JSON output of r.colors.out?

Would you prefer that I open an issue for discussion first, or should I go ahead and create a PR?

Sounds like discussing it in an issue might be better.