haml/haml
Haml
Haml is a Ruby HTML template engine and server-side rendering library. It functions as an HTML markup preprocessor that transforms a concise, indentation-based shorthand syntax into standard HTML and XHTML markup.
The system uses hierarchical whitespace instead of explicit closing tags to define the structure of documents, reducing boilerplate during markup authoring. It integrates Ruby logic directly into templates to evaluate conditional statements, process dynamic data, and interpolate values.
The engine provides tools for managing element attributes through hashes, controlling output whitespace, and generating document doctypes. It also supports text filters for processing blocks of content and provides integration as a middleware module for web frameworks or as a command-line utility.
Features
- HTML Markup Generators - Transforms a concise, indentation-based shorthand syntax into standard HTML tags and nested structures.
- Indentation-Based Parsers - Uses hierarchical whitespace to determine element nesting and automatically generate closing tags.
- Concise Markup Syntax - Provides a streamlined, indentation-based syntax for creating HTML structures with minimal boilerplate.
- HTML Generation Engines - Compiles a concise, indentation-based shorthand syntax into standard HTML documents.
- Dynamic Markup Rendering - Integrates backend Ruby logic into markup to render web pages based on variables and conditional data.
- Markup To HTML Converters - Transforms shorthand, indentation-based markup into standard HTML output.
- Indentation-Based Nesting - Uses indentation to define element hierarchy and automatically generate corresponding opening and closing tags.
- String-to-Code Execution - Integrates logic into templates by executing Ruby code to output results or run control statements.
- HTML Compilation - Transforms shorthand, indentation-based syntax into standard HTML via a compiler.
- Template Logic - Provides control structures within templates to conditionally render HTML elements based on Ruby logic.
- Silent Logic Execution - Allows backend Ruby code to process data within a template without rendering output to the final document.
- Indentation-Based Template Languages - Uses a hierarchical whitespace system instead of explicit closing tags to define the structure of HTML documents.
- Text Interpolations - Embeds variables and Ruby expressions directly into text literals using shorthand interpolation syntax.
- Server-Side Template Engines - Renders dynamic web responses on the server by injecting application data into HTML templates.
- Dynamic Content Insertion - Injects dynamic calculated values and Ruby expression results into the output text stream.
- Ruby - Injects and evaluates Ruby expressions directly within templates to produce dynamic content.
- HTML Preprocessing - Transforms a simplified, indentation-based markup language into valid HTML or XHTML.
- Ruby Template Engines - Implements a template system designed for the Ruby ecosystem that generates markup using embedded logic.
- Server-Side Rendering Frameworks - Provides a framework for rendering web pages on the server by interpolating dynamic data before sending HTML to the client.
- Shorthand Element Definitions - Creates HTML tags using a simple prefix to automatically generate matching opening and closing tags.
- Template Logic - Provides syntax and control structures within templates to conditionally render content or output dynamic values.
- Template Whitespace Control - Provides syntax markers to strip unnecessary blank lines and spaces from rendered templates.
- External Filter Integrations - Integrates external processing engines to filter and transform text blocks before final markup injection.
- Text Processing Filters - Enables the definition of custom filter classes to process text blocks before they are rendered.
- Preprocessing Filters - Processes text blocks through external engines like Markdown or Sass before inserting them into the document.
- Template Whitespace Control - Provides tools to control the surrounding or internal whitespace of tags for precise HTML formatting.
- Shorthand Attribute Assignments - Uses hashes and CSS shortcuts to rapidly assign common HTML attributes and classes to elements.
- Hash-to-Attribute Mapping - Provides a shorthand syntax for converting Ruby hashes into HTML attribute-value pairs.
- Attribute Mapping - Enables the definition of HTML attributes using Ruby hashes with support for boolean values and recursive expansion.
- Whitespace Preservation - Replace newlines with HTML entities in specific tags to prevent automatic indentation from altering output.
- Web Framework Integrations - Offers middleware and adapters that connect the templating engine to various web frameworks.
- Whitespace Control Systems - Prevent reformatting of indentation for whitespace-sensitive elements like pre and textarea.
- Template Engines - HTML abstraction markup language.
