feat: Page Templates.

[amiller-gh]

Began implementing https://github.com/vapid/vapid/issues/158 here so we can play with it and get a feel for the new data model features 🙂

Data Model Updates

• [x] Rename sections table to templates
• [x] Add a type column in the templates table of type ENUM(setting, form, page, collection).
• [x] Set all multiple=1 templates to type collection
• [x] Set all form=1 templates to type form
• [x] Set all other template types to setting
• [x] Drop form and multiple columns from templates
• [x] Rename the records.section_id column to records.template_id
• [x] Generate type=page template entries for each discovered /[^_]*.html file.
• [x] Generate a default page record instance for each template entry

Template Parser Updates

• [x] Use the Handlebars parser ASTs for improved template parsing, hash validation, template rewrites, partials support, and page rendering
• [x] Discover all data paths that start with this. inside of page templates and add them to the page's template entry as fields.
• [x] Discover all data paths with no context prefix and log a deprecation warning. Automatically insert general. as the path context to avoid this. conflicts.
• [x] Discover all data paths with the _ pseudo-private prefix and log a deprecation warning. Automatically rewrite _ paths to @ for proper Handlebars data attribute rendering support.
• [x] Add the {{#collection name as |value|}} block helper to the runtime and analyzer.
• [x] Update the {{#section name multiple=true}} helper to analyze a type=collection
• [x] Deprecate and the {{#section name multiple=true}}
• [ ] Rewrite the {{#section name multiple=true}} to {{#collection name as |value|}} (this is hard and requires children path rewrites... may not be reasonably possible.)

Dashboard Updates

• [x] Display Pages in the admin dashboard as single records.
• [x] Allow users to create new Pages, selecting from the project Page templates as data structure options.
• [x] Allow users to delete Pages (including the default created ones)
• [ ] Allow users to create new Collection instances, selecting from the available templates.
• [ ] Allow users to delete Collection instances – including the default Collection created.
• [ ] Add collection directive for the dashboard – users may select from a list of collections that use the same template.

Came up with an idea as I was working here: What if we allow {{#collection this.name as |value|}} (note: this.name instead of name). This would make a page-specific collection. It won't be shared between other pages and will show up as a direct child of the page in the dashboard. Essentially, each page instance will get a private collection to reference.

Also:

• Updated runtime to use Handlebars AST.
• Updated analyzer to user Handlebars AST.
• Navigation data property.
• Use native @ data props for private values.
• Full partials support.
• Custom page slug support.
• Site nav UI in dashboard.

[amiller-gh]

Experimental pages side menu, site navigation config, and "create new page" button visuals:

Global site navigation can be referenced in-template like:

<nav class="nav" id="sidebar">
  <ul class="nav__links">
    {{#collection @navigation as |page|}}
      <li>
        <a href="{{page.permalink}}" class="{{if page.isActive "active"}}">
          {{page.title}}
        </a>
      </li>
    {{/collection}}
  </ul>
</nav>

[amiller-gh]

Merging into master to open a PR in the main repo – this is in a decent draft state :)