zotonic-elm-to-templates

name: zotonic-elm-to-templates description: Use when converting Elm-generated Zotonic pages to Zotonic template_compiler templates. Focuses on extracting Elm routes/views into templates, using resource page paths, category templates, catinclude, page headers, and avoiding language-specific dispatch.

Zotonic Elm To Templates

Goal

Convert Elm-rendered pages into Zotonic templates while preserving behavior and URLs through Zotonic resources, dispatch, and template inheritance.

Discovery

• Read the Elm files first, especially route definitions, page/view modules, navigation, footer, forms, and any hard-coded page paths.
• Create a path inventory in doc/ when migrating routes: list resource names and all language page paths found in Elm. Pad table columns for human review when requested.
• Use live or old-site HTML/CSS only as reference; implement the result in Zotonic templates.

Routing

• Zotonic handles language path prefixes. Do not add /en, /nl, etc. dispatch variants.
• Keep dispatch names language-neutral, for example activities_agenda, not activities_agenda_en.
• Keep English route names in dispatch for now unless the user asks for localized route names.
• If a URL points to a named page resource, use m.rsc.resource_name.page_url instead of adding a dispatch rule.
• Use {% url dispatch_name %} for non-resource controller/dispatch routes.

Template Structure

• Put templates in the app/site priv/templates.
• Use English as the source language for all static template text. Move Dutch or other old-site literals into PO translations instead of keeping them in templates.
• Wrap user-visible text with {_ ... _}. For translated include arguments, use title=_"Text".
• Translate Elm view structure into semantic HTML, not a one-to-one div tree. Prefer header, nav, main, section, article, and footer.
• Preserve accessibility while converting: keep useful image alt text, add missing aria-* attributes where controls need labels, and use lowercase HTML tags/attributes.
• Treat URL/query values from q as unsafe in templates unless escaped or sanitized. m.rsc values are sanitized; values from other models should be escaped or otherwise checked.
• Use:

{% extends "page.tpl" %}

for page variants, and let page.tpl extend base.tpl.

• Use category-specific filenames:
  • page.event.tpl for resources in category event
  • page.building_private.tpl for category building_private
  • page.name.home.tpl only for specific named resources when a normal home.tpl is not the intended template
• Remove one-use include templates by inlining their content.
• Move grouped partials into directories when useful, for example:
  • form/_form_*.tpl
  • icon/_icon_*.tpl
  • page-header/_page_header*.tpl
• If converted pages use images, check priv/templates/mediaclass.config for existing mediaclasses before inventing image sizes.

Category Selection

• Prefer {% catinclude %} where the page/header/body varies by resource category.
• Typical pattern:

{% catinclude "page-header/_page_header.tpl" id %}

• Implement category variants as files that match the category-aware catinclude pattern.
• Before creating category templates, inspect fixture categories and Elm page modules. If a category has a matching Elm page view, create the corresponding page.category.tpl.

Base And Standard Includes

• Use Zotonic standard includes:
  • {% all include "_html_head.tpl" %}
  • standard body all-includes such as _html_body as seen in local Zotonic 1.x sites
• Remove head/body tags already provided by Zotonic modules.
• Remove Google Tag Manager snippets when mod_seo provides them.
• Check comparable Zotonic 1.x sites in the workspace for html and body attributes used by Cotonic and Zotonic.

Navigation And Footer

• Translate all Elm navigation/footer elements, including ticket buttons, search, language switch, social links, and image/icon buttons.
• Preserve translations by converting Elm language-specific text into English source msgids plus PO entries.
• Avoid duplicating the language switch.
• Preserve visual affordances from the live site, such as image-based back-to-top/continue controls and arrow icons in footer buttons.
• Replace hard-coded internal links with {% url ... %} or m.rsc.name.page_url.

Translation Workflow

• After converting text from Elm to templates, run:

bin/zotonic pot sitename

• The command uses the running Zotonic server. If Zotonic is already running, do not start it separately.
• Merge existing language files with msgmerge --backup=none --update.
• Add missing languages with msginit, for example de.po.
• Fill translations for newly introduced English msgids, especially labels, email text, admin help text, and form copy.
• Validate with msgfmt --check --output-file=/dev/null.
• Scan templates for old Dutch/source strings after edits; keep frontend templates language-neutral and translatable.

CSS And Layout Checks

• After template/CSS changes, check for horizontal scrolling, logo alignment, missing icons, and duplicated UI.
• Prefer fixing layout at the source: oversized width, viewport-width elements, negative margins, or uncontained images.
• Avoid inline styles from Elm output unless they are truly dynamic; prefer existing SCSS/CSS patterns in priv/lib-src.