How to cache AutoHtml output in a Rails model?

Override the attribute setter in your ActiveRecord model to call the AutoHtml pipeline and save the result to a separate column. The README provides an example with the Comment model using text and text_html columns for efficient storage.

AutoHtml or Redcarpet for Markdown in Ruby?

AutoHtml is better when you need to combine Markdown with other transformations like auto-linking or emoji conversion in a pipeline. Redcarpet is a dedicated Markdown parser with more formatting options but lacks AutoHtml's modularity for mixed-format processing.

Can I use AutoHtml to embed YouTube videos?

Not out of the box; AutoHtml's bundled filters don't include video embedding. You would need to create a custom filter to detect and convert video URLs into embed codes, leveraging the pipeline architecture.

How to add a new filter to AutoHtml?

Create a Ruby class with a #call method that takes a string and returns the transformed string. Then, integrate it into an AutoHtml::Pipeline instance, following the modular design pattern outlined in the abstract section of the README.

Is AutoHtml safe for user input?

It includes the HtmlEscape filter to prevent XSS by escaping HTML entities, but for robust sanitization against complex attacks, you may need to supplement it with additional libraries or custom filters tailored to your security needs.

How to change the emoji image source in AutoHtml?

The bundled Emoji filter uses default image paths; customization requires modifying the filter or creating a custom version, as it doesn't expose configuration options for altering image URLs directly in the provided examples.

auto_html — Ruby Text-to-HTML Pipeline

What is auto_html?

AutoHtml is a Ruby gem that transforms plain text into HTML using a collection of composable filters. It solves the problem of automating common text conversions—like turning URLs into links, parsing Markdown, or converting emoji codes—by providing a modular pipeline system. Developers can chain filters to create custom formatting rules without writing repetitive transformation logic.

Target Audience

Ruby and Rails developers who need to automate HTML generation from user-generated content, such as comments, posts, or documentation. It's particularly useful for applications where text requires multiple formatting steps (e.g., blogs, forums, or CMS platforms).

Value Proposition

AutoHtml offers a clean, extensible pipeline architecture that simplifies complex text transformations. Unlike monolithic libraries, its filter-based design allows precise control over formatting order and reuse across projects, with built-in performance optimizations like database caching for ActiveRecord.

Collection of filters that transform plain text into HTML code.

Use Cases

Best For

Converting plain-text user comments into formatted HTML with links and emojis
Processing Markdown content alongside custom transformations like auto-linking
Building reusable text-processing pipelines for Rails applications
Automating HTML generation from mixed-format content in CMS platforms
Caching formatted HTML in database columns to reduce runtime overhead
Adding emoji support to text-based content without manual image tagging

Not Ideal For

Real-time applications requiring client-side text processing without server-side Ruby execution
Projects needing comprehensive HTML sanitization beyond basic entity escaping
Teams seeking out-of-the-box formatting with no pipeline configuration

Pros & Cons

Pros

Modular Pipeline Architecture

Implements the Pipes and Filters pattern, allowing developers to chain and nest filters like Link and Markdown for customizable transformations, as shown in the README examples.

Built-in Common Filters

Includes ready-to-use filters for links, images, Markdown, and emojis, reducing the need to write boilerplate code for standard text conversions.

ActiveRecord Integration for Caching

Simplifies performance optimization by enabling formatted HTML to be stored in database columns, avoiding regeneration on each access, as demonstrated in the ActiveRecord example.

Cons

Limited Default Filter Set

Only provides a handful of bundled filters; advanced features like video embedding or custom sanitization require implementing additional filters from scratch.

Pipeline Order Complexity

Requires careful ordering of filters to avoid issues, such as placing Image before Link to prevent URL conflicts, which can lead to subtle bugs if mismanaged.

Ruby-Only Dependency

Tied to Ruby ecosystems, making it unsuitable for projects using other languages or requiring cross-platform text processing solutions.

What is auto_html?

Target Audience

Value Proposition

Use Cases

Best For

Converting plain-text user comments into formatted HTML with links and emojis
Processing Markdown content alongside custom transformations like auto-linking
Building reusable text-processing pipelines for Rails applications
Automating HTML generation from mixed-format content in CMS platforms
Caching formatted HTML in database columns to reduce runtime overhead
Adding emoji support to text-based content without manual image tagging

Not Ideal For

Real-time applications requiring client-side text processing without server-side Ruby execution
Projects needing comprehensive HTML sanitization beyond basic entity escaping
Teams seeking out-of-the-box formatting with no pipeline configuration

Pros & Cons

Pros

Modular Pipeline Architecture

Implements the Pipes and Filters pattern, allowing developers to chain and nest filters like Link and Markdown for customizable transformations, as shown in the README examples.

Built-in Common Filters

Includes ready-to-use filters for links, images, Markdown, and emojis, reducing the need to write boilerplate code for standard text conversions.

ActiveRecord Integration for Caching

Simplifies performance optimization by enabling formatted HTML to be stored in database columns, avoiding regeneration on each access, as demonstrated in the ActiveRecord example.

Cons

Limited Default Filter Set

Only provides a handful of bundled filters; advanced features like video embedding or custom sanitization require implementing additional filters from scratch.

Pipeline Order Complexity

Requires careful ordering of filters to avoid issues, such as placing Image before Link to prevent URL conflicts, which can lead to subtle bugs if mismanaged.

Ruby-Only Dependency

Tied to Ruby ecosystems, making it unsuitable for projects using other languages or requiring cross-platform text processing solutions.

auto_html

What is auto_html?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

auto_html

What is auto_html?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?