handlebars-lang/handlebars.js
Handlebars.js
Handlebars.js is a JavaScript templating engine and logic-less template library used to generate HTML or text by merging data objects with templates. It utilizes an abstract syntax tree parser to transform template strings into executable JavaScript functions.
The system separates data from presentation by restricting complex logic to external helper functions rather than the template itself. It features a precompiled template compiler that converts templates into functions before deployment to increase execution speed and reduce startup latency.
The engine covers a broad range of content generation capabilities, including object iteration, recursive partial templates, and whitespace management. It supports both client-side and server-side rendering while providing security measures such as prototype access restrictions and the prevention of remote code execution through property whitelisting.
Features
- HTML Template Renderers - Generates final HTML markup by merging data contexts with predefined templates.
- AST-Based Template Parsing - Converts template strings into an abstract syntax tree to analyze structure without immediate execution.
- Template Compilation - Transforms template strings into executable JavaScript functions to optimize rendering performance.
- Prototype Pollution Protections - Prevents unauthorized execution of internal methods by restricting access to object prototype properties via a whitelist.
- Remote Code Execution Mitigations - Hardens the system against exploits by blocking access to class constructors and internal functions within templates.
- Abstract Syntax Tree Parsers - Transforms template strings into an abstract syntax tree for structured analysis and manipulation.
- Template Helpers - Provides a system for extending template logic via external JavaScript helper functions.
- Logic-less Template Engines - Provides a logic-less templating system that separates data from presentation using an extended syntax.
- Collection Iterators - Iterates over data collections to generate repeated content within the rendered output.
- HTML Templating Engines - Processes structured templates to generate dynamic HTML for web pages and emails.
- Template Data Binding - Resolves template variables by traversing data object hierarchies using specified lookup paths.
- Template Logic - Provides custom helper functions and block expressions to implement specific logic and formatting during rendering.
- Template Partials - Allows the creation of reusable template fragments that can be dynamically embedded.
- Precompiled Template Execution - Executes precompiled templates as standalone functions to eliminate parsing overhead during runtime.
- Template Security Policies - Applies security constraints to prevent injection attacks and prototype pollution with untrusted data.
- Startup Optimizers - Reduces startup latency by converting templates into executable JavaScript code before runtime.
- Client-Side Template Rendering - Generates dynamic markup directly in the browser by executing precompiled template functions.
- Server-Side Template Engines - Renders dynamic application data into HTML templates on the server side.
- Partial Templates - Supports recursive nesting of reusable template fragments through named identifiers.
- Templating - Mustache-based templating with helper support.
- Templating Engines - An extension to the Mustache templating language.
