ogc

OGC API

OGC APIs are constructed by different building blocks. These building blocks are composed of the different OGC API standards. Each OGC building block resides in its own Go package.

• package common represents OGC API Common.
• package features represents OGC API Features. It's the most extensive building block.
• package feature_search is NOT part of the OGC API standard, but build on top of OGC API Features. It's an API for geocoding and searching features across multiple collections. The need for this functionality is also expressed in an OGC feature request. This building block was previously known as gomagpie.
• package geovolumes represents OGC API 3D GeoVolumes / 3D Tiles.
• package processes represents OGC API Processes.
• package styles represents OGC API Styles.
• package tiles represents OGC API Tiles.

When coding, we try to use the naming convention as used by the OGC, so it is clear which specification or part is referred to in code.

Coding

Templates

We use templates to generate static/pre-defined API responses based on the given GoKoala configuration file. Lots of OGC API responses can be statically generated. Generation happens at startup and results are served from memory when an API request is received. Benefits of this approach are:

• Lightning fast responses to API calls since everything is served from memory
• Fail fast since validation is performed during startup

Duplication

We will have duplication between JSON and HTML templates: that's ok. They're different representations of the same data. Don't try to be clever and "optimize" it. The duplication is pretty obvious/visible since the files only differ by extension, so it's clear any changes need to be done in both representations. Having independent files keeps the templates simple and flexible.

IDE support

See README in the root.

Tip: handling JSON

When generating JSON arrays using templates you need to be aware of trailing commas. The last element in an array must not contain a comma. To prevent this, either:

• Add the comma in front of array items
• Use the index of a range to check array position and place the comma based on the index
• The most comprehensive solution is to use:

{{ $first := true }}
{{ range $_, $element := .}}
{{if not $first}}, {{else}} {{$first = false}} {{end}}
{{$element.Name}}
{{end}}