README

Image support for CKEditor for TYPO3

Version 13.0.x for TYPO3 13.4+ License: AGPL-3.0-or-later

This extension adds comprehensive image handling capabilities to CKEditor for TYPO3.
Add issues or explore the project on GitHub.

Features

TYPO3 FAL Integration: Native file browser with full File Abstraction Layer support
Magic Images: Same image processing as rtehtmlarea (cropping, scaling, TSConfig supported)
Image Dialog: Configure width, height, alt, and title (aspect ratio automatically maintained)
Custom Styles: Configurable image styles with CKEditor 5 style system
Lazy Loading: TYPO3 native browser lazyload support
Event-Driven: PSR-14 events for extensibility

Requirements

TYPO3: 13.4 or later
PHP: 8.2, 8.3, or 8.4
Extensions: cms-rte-ckeditor (included in TYPO3 core)

Critical Dependencies (v13.0.0+)

The CKEditor plugin requires these dependencies for style functionality:

# In your RTE YAML configuration
importModules:
  - '@ckeditor/ckeditor5-html-support'

Important: Missing GeneralHtmlSupport will disable the style dropdown for images. See Documentation for details.

Installation

Quick Start

Install the extension via composer:

composer req netresearch/rte-ckeditor-image

That's it! The extension works completely out-of-the-box with zero configuration:

✅ Backend RTE: Automatically registers the rteWithImages preset and configures the toolbar with insertimage button for all sites
✅ Frontend Rendering: Automatically loads TypoScript for proper image rendering via lib.parseFunc_RTE
✅ No Manual Steps: No template inclusion, no TSConfig setup, no YAML configuration required

Custom Configuration (Optional)

If you need to customize the RTE configuration or create your own preset:

Create a custom preset in your site extension:

<?php
// EXT:my_ext/ext_localconf.php
$GLOBALS['TYPO3_CONF_VARS']['RTE']['Presets']['my_custom_preset']
    = 'EXT:my_ext/Configuration/RTE/Default.yaml';

Import the image plugin configuration:

# EXT:my_ext/Configuration/RTE/Default.yaml
imports:
  - { resource: "EXT:rte_ckeditor/Configuration/RTE/Default.yaml" }
  - { resource: "EXT:rte_ckeditor_image/Configuration/RTE/Plugin.yaml" }

editor:
  config:
    toolbar:
      items:
        - heading
        - '|'
        - insertimage
        - link
        - '|'
        - bold
        - italic

Enable your custom preset via Page TSConfig:

# Page TSConfig
RTE.default.preset = my_custom_preset

Configuration

(optional) Configure the Extension Configuration for this extension:

fetchExternalImages: By default, if an img source is an external URL, this image will be fetched and uploaded to the current BE users uploads folder. The default behaviour can be turned off with this option.

Maximum width/height

The maximum dimensions relate to the configuration for magic images which have to be set in Page TSConfig:

# Page TSConfig
RTE.default.buttons.image.options.magic {
    # Default: 300
    maxWidth = 1020
    # Default: 1000
    maxHeight = 800
}

Current versions of TYPO3 won't render TSConfig settings correctly out of custom template extensions (see the corresponding T3 bug: https://forge.typo3.org/issues/87068). In this case just add the settings to root page config.

Usage as lightbox with fluid_styled_content

# Template Constants
styles.content.textmedia.linkWrap.lightboxEnabled = 1

Configure a default css class for every image

# TS Setup

lib.parseFunc_RTE {
    // default class for images in bodytext:
    nonTypoTagStdWrap.HTMLparser.tags.img.fixAttrib.class {
      default = my-custom-class
    }
}

Image lazyload support

The extension supports TYPO3 lazyload handling (fluid_styled_content) for native browser lazyload.

# Template Constants type=options[lazy,eager,auto]
styles.content.image.lazyLoading = lazy

Using original images without processing (noScale)

To use original images without processing (useful for newsletters, PDFs, or retina displays):

# TypoScript Setup - Enable globally for all RTE images
lib.parseFunc_RTE.tags.img.noScale = 1

# Or enable for linked images
lib.parseFunc_RTE.tags.a.noScale = 1

# Optional: Set file size threshold for auto-optimization
lib.parseFunc_RTE.tags.img {
    noScale = 1
    noScale {
        # Maximum file size in bytes for auto-optimization
        # Prevents serving very large original files
        maxFileSizeForAuto = 2000000  # 2MB
    }
}

When noScale = 1:

Original image files are used (no processed variants in typo3temp/)
Image quality is preserved at maximum resolution
Width and height attributes are still calculated and applied
Ideal for newsletters, PDFs, and high-resolution displays

Auto-Optimization: Even with noScale = 0 (default), the extension automatically skips processing when:

Requested dimensions match the original image dimensions
SVG files are detected (vector graphics always use original)

File Size Threshold: Control auto-optimization for large files using maxFileSizeForAuto (in bytes). When set, files exceeding this size will be processed even if dimensions match, preventing oversized originals from being served.

Allowed extensions

By default, the extensions from $TYPO3_CONF_VARS['GFX']['imagefile_ext'] are allowed. However, you can override this for CKEditor by adding the following to your YAML configuration:

editor:
  externalPlugins:
      typo3image:
        allowedExtensions: "jpg,jpeg,png"

Documentation

This project maintains three documentation tiers:

Official TYPO3 Documentation

Published Manual: https://docs.typo3.org/p/netresearch/rte-ckeditor-image/main/en-us/

For integrators, administrators, and end users. Covers installation, configuration, troubleshooting, and usage.

Source: Documentation/ (RST format, automatically built and published)

AI Development Context

AI Agents & Developers: claudedocs/INDEX.md

Comprehensive technical knowledge base including:

Architecture & Design - System design, components, security
API Reference - Complete PHP API documentation
Development Guide - Workflow, standards, testing
Security Analysis - Threat model, protections, best practices

Note: claudedocs/ is gitignored - generated per session for AI context only.

Project Essentials

AGENTS.md - AI development guide and build commands
CONTRIBUTING.md - Contribution guidelines
SECURITY.md - Security policy
Documentation/AGENTS.md - TYPO3 documentation system guide

Development

DDEV Environment (Complete Testing Setup)

# Quick start with DDEV (includes TYPO3 + Introduction package)
git clone https://github.com/netresearch/t3x-rte_ckeditor_image.git
cd t3x-rte_ckeditor_image
make up                      # Start DDEV + complete setup (ONE COMMAND!)

# Access your environment
# - Overview:       https://rte-ckeditor-image.ddev.site/
# - Documentation:  https://docs.rte-ckeditor-image.ddev.site/
# - TYPO3 Frontend: https://v13.rte-ckeditor-image.ddev.site/
# - TYPO3 Backend:  https://v13.rte-ckeditor-image.ddev.site/typo3/
# - Credentials:    admin / Password:joh316

# Individual commands
make start                   # Start DDEV environment
make setup                   # Complete setup (docs + install)
make docs                    # Render extension documentation

Local Development (No DDEV)

# Quick start
composer install
make help                    # See all available targets

# Development workflow
make lint                    # Run all linters
make format                  # Fix code style
make test                    # Run tests
make ci                      # Full CI check (pre-commit)

See AGENTS.md for complete development guide, code standards, and PR checklist.

Deployment

Developed on GitHub
Composer repository
TYPO3 Extension Repository
New versions automatically uploaded to TER via GitHub Action when creating a release

netresearch / rte-ckeditor-image

Maintainers

Details