Python Renderers and Resolvers

Add processing logic when templates alone are not enough.

Python Renderers and Resolvers

Templates are best for presentation. Python extension points are useful when a site format needs logic: normalizing resume entries, grouping publications, fetching page data, or turning a folder into a structured page.

Custom Renderers

from webifier.core.base import RendererModule


class ResumeRenderer(RendererModule):
    template = "renderers/resume.html"
    META_KEYS = frozenset({"kind", "template", "profile", "experience"})

Package the renderer inside an extension:

from webifier.core.extensions import Extension


class ResumeExtension(Extension):
    id = "my.resume"
    renderers = {
        "resume": "my_resume.renderers.ResumeRenderer",
    }
    template_dirs = ["/path/to/my_resume/templates"]

Expose it through package entry points:

[project.entry-points."webifier.extensions"]
"my.resume" = "my_resume.extension:ResumeExtension"

Then enable it in a site:

webifier:
  extensions:
    resume:
      uses: my.resume

profile:
  kind: resume

Custom Resolvers

Resolvers compute values inside YAML:

def year(value, ctx):
    return value[:4]

Register them through an extension:

from webifier.core.extensions import Extension


class DatesExtension(Extension):
    id = "my.dates"
    resolvers = {
        "year": "my_dates.resolvers.year",
    }

published: ${year:2026-06-13}

Extensions are configured before interpolation, so custom resolvers can be used in the same site file that enables them.

For full details, see Resolver System and Extension and Customization Guide.