semantic-html

name	semantic-html
description	Build semantic, accessible, framework-driven frontend interfaces in Builderius. Use when building pages, sections, layouts, components, or any visual design task in the Builderius builder. Covers landmark planning, heading hierarchy, proper tag selection, list patterns, forms, tables, and Collection loops.

Builderius Semantic HTML

Write meaningful HTML through Builderius modules that serves all users and respects the web platform.

When to Use This Skill

• Creating new sections or page layouts in the Builderius builder
• Reviewing existing module trees for semantic correctness
• Deciding which tag value to set on an HtmlElement module
• Structuring documents with proper heading hierarchy
• Building forms with SmartForm and proper labelling
• Creating data loops with Collection/Template modules
• Adding ARIA attributes to improve accessibility

Before You Start

1. Call builderius_builder_get_css_framework to discover available classes and variables
2. Read builderius://design-guidelines for full methodology, CSS patterns, and data patterns
3. Read builderius://modules-reference for available module types

Framework classes → entity CSS → module CSS (cascade order).

Builderius Module-to-HTML Mapping

Every HtmlElement module renders as the HTML tag defined in its tag setting. Choose the tag for semantic meaning, not visual appearance.

Module Type	Renders As	Key Settings
HtmlElement (tag=section)	<section>	tag, tagClass, htmlAttribute, content
HtmlElement (tag=article)	<article>	Same as above
HtmlElement (tag=nav)	<nav>	Same — always add aria-label
HtmlElement (tag=header)	<header>	Same
HtmlElement (tag=footer)	<footer>	Same
HtmlElement (tag=main)	<main>	Same — only one per page
HtmlElement (tag=aside)	<aside>	Same
HtmlElement (tag=h1–h6)	<h1>–<h6>	content for heading text
HtmlElement (tag=img)	<img>	mediaUrl for src, void — no children
HtmlElement (tag=a)	<a>	href for link destination, content for text
HtmlElement (tag=button)	<button>	content for button text
Collection	<div has="collection">	data-b-context via htmlAttribute
Template	<template>	Loop wrapper — use {{field}} syntax inside
SmartForm	<builderius-smart-form>	data-method, data-action via htmlAttribute
HtmlCode	raw HTML injection	contentHtml — for SVG icons, embeds
SvgCode	raw SVG injection	contentSvg — for inline SVGs
Component	transparent wrapper	componentName — renders component content

Void Tags — Cannot Have Children

These tags are self-closing. Never nest child modules inside them:

img, input, br, hr, textarea, embed, source, track, wbr, col, area, base, link, meta, param

Core Principles

1. Landmarks First

Before building individual components, plan the full page structure. This allows you to:

• Identify key landmarks for assistive technology users
• Plan heading hierarchy across the entire document
• Avoid overusing landmarks (which diminishes their usefulness)

Standard Builderius page template structure:

root
  HtmlElement tag=a          → Skip navigation link (class: skip-navigation)
  Component                  → Site Header (contains <header> and <nav>)
  HtmlElement tag=main       → Main content (id="content")
    HtmlElement tag=section  → Section 1 (aria-labelledby=heading-id)
    HtmlElement tag=section  → Section 2
    ...
  Component                  → Site Footer (contains <footer>)

Landmark element guide:

Tag	Use When	Builderius Notes
main	Primary page content	Only one per template. Add id="content" via add_html_attribute.
header	Page or section intro	Use for section intro areas, not just the site header.
footer	Page or section closing	Contact info, copyright, related links.
nav	Navigation sections	Must have aria-label. Never include "navigation" in the label.
section	Thematic grouping	Only becomes a landmark when labelled via aria-labelledby.
article	Self-contained content	Blog posts, movie cards, comments, product cards.
aside	Tangentially related	Sidebars, pull quotes, advertising.
search	Search functionality	Contains the search form, not the results.

2. Native Over ARIA

If a native HTML tag provides the semantics you need, use it. Do not add ARIA to a generic <div> when a proper element exists.

Red flags in a Builderius module tree:

• Multiple HtmlElement modules with tag=div that should be section, article, header, nav, or footer
• role attributes on elements that already have native roles (e.g., role="button" on a <button>)
• High ARIA attribute count on non-complex components

Decision tree:

Need a section wrapper?
  → Does it have a heading? → tag=section + aria-labelledby
  → No heading? → tag=div (section without label = div semantically)

Need a card/post container?
  → Would it make sense standalone? → tag=article
  → Just grouping? → tag=div

Need a clickable element?
  → Navigates to URL? → tag=a with href
  → Performs action? → tag=button
  → NEVER tag=div with onclick behavior

3. Separation of Visual and Semantic Hierarchy

CSS classes control appearance. HTML tags control meaning. In Builderius:

• Set the tag based on document structure and meaning
• Set tagClass (via add_module_class) for visual styling
• Use framework CSS variables for consistent visual treatment
• Create entity-scoped CSS classes for section-specific layout

Example: A heading that needs to look small but is semantically h2:

Module: HtmlElement
  tag: h2                    → semantic level (correct for document outline)
  tagClass: [font-size-1]   → visual size (framework class for smaller text)
  content: Section Title

4. Content Realism

Design content is idealized. Real content is messy. When building modules:

• Account for long titles that wrap to multiple lines
• Handle missing optional fields (e.g., no featured image, empty excerpt)
• Support dynamic content from Collections that varies in length
• Test with real data via get_dynamic_data before finalizing layout

Headings

Heading Hierarchy Rules

1. One h1 per template — typically the page/archive title
2. Never skip levels — h1 → h3 is invalid; use h1 → h2 → h3
3. Every <section> should start with a heading that matches its aria-labelledby
4. In Collection loops, headings inside the Template inherit the context of their parent section

Common Builderius heading structure:

main
  section (aria-labelledby="movies-heading")
    h2#movies-heading "Latest Movies"         → section heading
    Collection (loop)
      Template
        article
          h3 "{{post_title}}"                 → item heading (one level below section)
  section (aria-labelledby="team-heading")
    h2#team-heading "Our Team"                → next section, same level
    ul
      li
        h3 "Person Name"                      → item heading

Headings in Components

Builderius components are reusable. A component that contains a heading should:

1. Use a configurable heading tag — The component property can control which h level renders
2. Document the expected context — State what heading level the component assumes
3. Default to a safe level — h3 is a common default for card-level components

Visual Heading Without Semantic Heading

Sometimes text should look like a heading but not be one semantically. In Builderius:

Module: HtmlElement
  tag: p                     → NOT a heading semantically
  tagClass: [movies-title]   → CSS class provides heading-like appearance
  content: "Sale ends tomorrow!"

Use this pattern for eyebrow labels, promotional text, and decorative typography that don't introduce content sections.

Lists

When to Use Lists

Use lists when knowing the count of items helps the user:

• Navigation menus → <ul> (how many options?)
• Search results → <ul> (how many matches?)
• Steps in a process → <ol> (what order?)
• Glossary/metadata → <dl> (term-description pairs)

Builderius List Patterns

Static list:

HtmlElement tag=ul (tagClass: [team-list], htmlAttribute: [role=list])
  HtmlElement tag=li (tagClass: [team-person])
    ...
  HtmlElement tag=li
    ...

Dynamic list via Collection:

Collection tag=ul (tagClass: [movies-grid], data-b-context="[[movies.posts_query.posts]]")
  Template
    HtmlElement tag=li
      HtmlElement tag=article
        ...

Note: When CSS list-style: none is applied, add role="list" via add_html_attribute to preserve list semantics in Safari/VoiceOver.

Definition Lists

Use <dl> for metadata, key-value pairs, and glossaries:

HtmlElement tag=dl
  HtmlElement tag=dt — content: "Director"
  HtmlElement tag=dd — content: "Steven Spielberg"
  HtmlElement tag=dt — content: "Year"
  HtmlElement tag=dd — content: "1993"

Interactive Elements

Buttons vs Links

Interaction	Use	Builderius Tag
Navigate to a URL	Link	tag=a with href
Perform an action (submit, toggle, delete)	Button	tag=button
Navigate to a URL that also has a JS action	Link	tag=a with href (progressive enhancement)
Card that links to a detail page	Link wrapping content	tag=a wrapping the card, or tag=article with a link inside

Never use tag=div with a click handler for actions. Use tag=button or tag=a.

The Details/Summary Pattern

For progressive disclosure (FAQ, expandable sections):

HtmlElement tag=details
  HtmlElement tag=summary — content: "How do I cancel my subscription?"
  HtmlElement tag=p — content: "You can cancel anytime from your account settings..."

Forms

SmartForm Module

For forms in Builderius, use the SmartForm module:

SmartForm (data-method="post", data-action="/contact", aria-label="Contact form")
  HtmlElement tag=div (tagClass: [field-group])
    HtmlElement tag=label — content: "Email", htmlAttribute: [for=email-input]
    HtmlElement tag=input — htmlAttribute: [type=email, id=email-input, name=email, required, aria-required=true]
  HtmlElement tag=button — content: "Submit"

Label Rules

1. Always use a <label> element. No exceptions.
2. Never rely on placeholder text as a label. Placeholders disappear on input.
3. Never use aria-label when a proper <label> element works.
4. Visually hidden labels are acceptable when design requires it — use a CSS class that hides visually but remains accessible.

Error Messages

HtmlElement tag=label — content: "Email", htmlAttribute: [for=email]
HtmlElement tag=input — htmlAttribute: [
  type=email,
  id=email,
  aria-invalid=true,
  aria-describedby=email-error
]
HtmlElement tag=p — content: "Enter a valid email address", htmlAttribute: [id=email-error, role=alert]

Fieldset/Legend for Grouping

Use for thematic groups of fields:

HtmlElement tag=fieldset
  HtmlElement tag=legend — content: "Shipping Address"
  (form fields...)

Tables

When to Use Tables

Use a table when data has meaningful relationships in both dimensions — each row has the same columns, and data within each column is of the same type.

Do NOT use tables for:

• Simple lists (one dimension) → use <ul>
• Key-value pairs → use <dl>
• Form layouts → use proper form elements
• Visual grids of cards → use CSS grid with <ul> or <div>

Table Semantic Baseline

HtmlElement tag=table
  HtmlElement tag=caption — content: "Quarterly Sales Report"
  HtmlElement tag=thead
    HtmlElement tag=tr
      HtmlElement tag=th — content: "Product", htmlAttribute: [scope=col]
      HtmlElement tag=th — content: "Q1", htmlAttribute: [scope=col]
  HtmlElement tag=tbody
    HtmlElement tag=tr
      HtmlElement tag=th — content: "Widget A", htmlAttribute: [scope=row]
      HtmlElement tag=td — content: "$10,000"

Always include: <caption>, <thead>/<tbody>, and <th> with scope attribute.

Collection Loops

Standard Loop Pattern

Collection (data-b-context="[[movies.posts_query.posts]]", tagClass: [movies-grid])
  Template
    HtmlElement tag=article (tagClass: [movie-card])
      HtmlElement tag=img — htmlAttribute: [src={{{featured_image.file_url}}}, alt={{post_title}}]
      HtmlElement tag=h3
        HtmlElement tag=a — href: {{{permalink}}}, content: {{post_title}}
      HtmlElement tag=p — content: {{post_excerpt}}

Variable Syntax

Syntax	Scope	Escaping
[[var]]	Template-level data variable	HTML-escaped
[[[var]]]	Template-level data variable	Unescaped (for URLs, HTML)
{{field}}	Loop-local field (inside Collection/Template)	HTML-escaped
{{{field}}}	Loop-local field	Unescaped (for URLs, HTML, image sources)

Rules:

• Use {{{...}}} (unescaped) for URLs in href and src attributes
• Use {{...}} (escaped) for visible text content
• Template-level [[...]] is accessible everywhere; loop-local {{...}} only inside a Template

Nested Loops (SubCollection)

For nested arrays (e.g., categories within a post):

Collection (data-b-context="[[posts]]")
  Template
    HtmlElement tag=article
      HtmlElement tag=h3 — content: {{title}}
      SubCollection (data-source={{categories}})
        Template
          HtmlElement tag=span — content: {{name}}

HtmlCode and SvgCode

Use these for raw code injection when Builderius modules are insufficient:

• HtmlCode: For complex HTML that can't be built with modules (e.g., icon SVGs inside links)
• SvgCode: For inline SVGs

Critical: These are leaf modules — no children, no htmlAttribute setting. All content goes in contentHtml or contentSvg.

When using HtmlCode for icons inside links:

• Add aria-hidden="true" to decorative SVGs within the contentHtml
• Add aria-label to the parent link/button module to provide an accessible name
• Include a visually hidden text span if the icon conveys meaning

Module Review Checklist

Positive Signals

• Landmark elements used for page structure (main, header, footer, nav, section, article)
• Logical heading hierarchy (h1 → h2 → h3, no skips)
• Sections have aria-labelledby pointing to their heading's id
• Images have meaningful alt text (not just the filename)
• Links have descriptive text (not "click here" or "read more" alone)
• Lists use <ul>/<ol> with <li> (not divs)
• Forms have proper <label> elements
• Collection loops use semantic wrappers (article, li)
• Framework CSS classes used before custom CSS
• CSS variables used for all visual tokens

Warning Signs

• High div count where semantic elements should be used
• Heading levels chosen for visual size rather than structure
• Images without alt attributes
• Links with no accessible text (icon-only without aria-label)
• Forms using placeholder text as labels
• role attributes on elements that already have native semantics
• Per-module css setting used as primary styling method
• Hardcoded color/spacing values instead of CSS variables

References

• HTML Living Standard: Sections
• MDN: ARIA
• Builderius Modules Reference
• See references/heading-patterns.md for component heading strategies