@diplodoc/liquid

A small and fast implementation of basic Liquid syntax for processing YFM (Yandex Flavored Markdown) documents. Provides template processing capabilities including variable substitutions, conditions, cycles (loops), and frontmatter handling.

Features

• Variable substitutions — {{ variable }} syntax
• Conditional blocks — {% if condition %}...{% endif %}
• Cycle/loop blocks — {% for item in collection %}...{% endfor %}
• Frontmatter processing — YAML frontmatter extraction and processing
• Source map support — Optional source maps for debugging
• Custom filters — Extensible filter system
• Code block preservation — Handles code blocks without processing Liquid syntax inside

Installation

npm install @diplodoc/liquid

Usage

Basic Example

import {createContext, liquidDocument} from '@diplodoc/liquid';

// Create a context with logger and settings
const context = createContext({
  info: console.log,
  warn: console.warn,
  error: console.error,
});

// Process a document with variables
const template = `
---
title: {{ title }}
---

Hello, {{ name }}!

{% if showDetails %}
Details: {{ details }}
{% endif %}
`;

const vars = {
  title: 'My Document',
  name: 'World',
  showDetails: true,
  details: 'Some important information',
};

const result = liquidDocument.call(context, template, vars);
// Result:
// ---
// title: My Document
// ---
//
// Hello, World!
//
// Details: Some important information

Processing Snippets

import {liquidSnippet} from '@diplodoc/liquid';

const snippet = 'Hello, {{ name }}!';
const vars = {name: 'World'};

const result = liquidSnippet.call(context, snippet, vars);
// Result: "Hello, World!"

Processing JSON

import {liquidJson} from '@diplodoc/liquid';

const json = {
  title: '{{ title }}',
  items: ['{{ item1 }}', '{{ item2 }}'],
};

const vars = {
  title: 'My Title',
  item1: 'First',
  item2: 'Second',
};

const result = liquidJson.call(context, json, vars);
// Result: { title: 'My Title', items: ['First', 'Second'] }

API

Functions

• liquidDocument(input, vars, sourcemap?) — Processes a full YFM document with frontmatter
• liquidSnippet(input, vars, sourcemap?) — Processes a Liquid template snippet (without frontmatter)
• liquidJson(json, vars) — Recursively processes Liquid syntax in JSON objects
• createContext(logger, settings?) — Creates a Liquid context for processing

Types

• LiquidContext — Context object containing logger, settings, and optional path
• LiquidSettings — Configuration options for Liquid processing
• SourceMap — Source map for tracking transformations

See TypeScript definitions for detailed API documentation.

Configuration

You can configure Liquid processing behavior via LiquidSettings:

const context = createContext(logger, {
  conditions: true, // Enable/disable conditions
  cycles: true, // Enable/disable cycles
  substitutions: true, // Enable/disable substitutions
  conditionsInCode: false, // Process conditions in code blocks
  keepNotVar: false, // Keep {{ var }} if variable not found
});

License

MIT