M4D Product Media

Custom WooCommerce product media handling for variable products, designed to replace WooCommerce’s default product image/gallery behavior with a more Shopify-like UX.

This plugin is actively under development and is intended to be worked on using Codex or similar AI-assisted coding tools. Please read this document fully before making changes.

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High-Level Goal

Replace WooCommerce’s default product image + gallery behavior with a stable, predictable, variation-aware media system that:

• Uses Swiper.js for the main image and thumbnails
• Supports variation-specific image galleries
• Avoids page reloads or DOM re-render loops
• Matches Shopify-style behavior as closely as possible

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Tech Stack

• WordPress
• WooCommerce (variable products)
• Custom WordPress plugin
• PHP (admin + frontend integration)
• JavaScript (jQuery)
• Swiper.js
• Elementor (frontend layouts)
• GitHub + Git Updater

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Core Functional Requirements

1. Initial Page Load (No Variation Selected)

• Main image:
  • Use the product featured image
• Thumbnail carousel:
  • Use the product’s main product gallery
• Swiper instances:
  • Initialized once
  • No DOM teardown
  • No reinitialization loops

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2. Variation Selected

When a variation is selected:

• Main image:
  • Switch to the variation’s main image
• Thumbnail carousel:
  • Replace contents with ONLY the variation’s gallery images
• Behavior:
  • No page reload
  • No Swiper reinitialization
  • No mutation that breaks Woo variation resolution

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3. Variation Gallery (Admin)

Each variation supports:

• A custom image gallery (in addition to the variation’s main image)
• Editable in the WooCommerce variation edit UI
• Images must:
  • Persist on save
  • Reappear on reload
  • Correctly trigger Woo’s “Save changes” state

This functionality replaces the need for paid WooCommerce extensions that add variation galleries.

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Explicit Non-Goals

• ❌ No reliance on image filename conventions
• ❌ No normalization of variation names (e.g. black-white vs white-black)
• ❌ No guessing or heuristic-based image matching
• ❌ No page reloads on variation changes
• ❌ No repeated Swiper initialization

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Critical Constraints / Lessons Learned

These are important — do not violate them.

Swiper + Woo Variations

• Swiper must be initialized once
• Rebuilding Swiper instances inside found_variation causes:
  • Infinite re-render loops
  • “Deferred DOM Node could not be resolved” errors
  • Page reload-like behavior

DOM Mutation Rules

• Do NOT:
  • Replace large DOM trees
  • Call location.reload()
  • Tear down Swiper containers
• DO:
  • Replace slide contents carefully
  • Preserve Swiper structure

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Known Past Issues (Avoid Reintroducing)

• Infinite frontend reload loop
• Backend “Connection lost” error in WP editor
• Variation gallery images not saving
• “Save changes” button not enabling for variations
• Frontend showing one variation image per Swiper “page”

These were caused by:

• Improper DOM manipulation
• Incorrect variation meta saving
• Swiper reinitialization
• Over-aggressive JS event handling

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Desired UX (Shopify-Style)

• One main image
• Thumbnail carousel below
• Arrows on main image
• Dots pagination under thumbnails
• Clean transitions
• Predictable behavior

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Development Rules

When modifying this plugin:

1. Prefer small, explicit changes
2. Avoid speculative refactors
3. Do not assume Woo behavior — verify it
4. Use full file replacements when providing code
5. Preserve existing structure unless explicitly changing it
6. Stability > cleverness

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How Codex Should Work With This Repo

Codex is expected to:

• Read existing files before modifying them
• Respect WooCommerce JS lifecycle events
• Avoid introducing reloads or re-renders
• Explain reasoning when making architectural changes
• Ask before removing or renaming existing behavior

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Versioning

Current version at time of writing: 0.2.5

Version bumps should:

• Reflect meaningful functional changes
• Be documented in commit messages

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Summary

This plugin exists because WooCommerce’s default product media handling is insufficient for complex, variation-heavy products.

The goal is correctness, stability, and UX parity with Shopify, not quick hacks.

If something seems fragile, it probably is — err on the side of robustness.