bblocks-jinja2-transform-plugin

Adds a jinja2 transform type to the OGC Building Blocks postprocessor.

The transform renders a Jinja2 template against JSON input data, producing any text-based output (HTML, XML, plain text, etc.).

Usage

Declare the plugin in transform-plugins.yml at the root of your building blocks repository:

plugins:
  - pip: git+https://github.com/ogcincubator/bblocks-jinja2-transform-plugin.git
    modules:
      - bbplugin_jinja2

Then declare a jinja2 transform in your transforms.yaml:

transforms:
  - id: html-summary
    type: jinja2
    inputs:
      mediaTypes: [application/json]
    outputs:
      mediaTypes:
        - mimeType: text/html
          defaultExtension: html
    code: |
      <dl>
      {% for key, value in data.items() %}
        <dt>{{ key }}</dt><dd>{{ value }}</dd>
      {% endfor %}
      </dl>

Template context

The JSON input is parsed and made available in two ways:

• data — the full parsed value (works for objects, arrays, and primitives)
• top-level keys — if the input is a JSON object, its keys are also injected directly as template variables

So given input {"name": "Alice", "role": "Engineer"}, both {{ data.name }} and {{ name }} resolve to "Alice".

Undefined variables raise an error (Jinja2 StrictUndefined).

Requirements

• Python ≥ 3.10
• Jinja2 (installed automatically by the postprocessor)