parser.md

Parser API

The wiremd parser converts markdown with wiremd syntax into an Abstract Syntax Tree (AST) that can be rendered or manipulated programmatically.

parse()

Parse markdown with wiremd syntax into an AST.

Signature

function parse(input: string, options?: ParseOptions): DocumentNode

Parameters

`input: string`

The markdown string to parse. Can include standard markdown syntax plus wiremd extensions for UI components.

`options?: ParseOptions`

Optional configuration for the parser:

interface ParseOptions {
  // Include position information in AST nodes (default: false)
  position?: boolean;

  // Validate the AST during parsing (default: false)
  validate?: boolean;

  // Enable strict mode (stricter syntax rules) (default: false)
  strict?: boolean;

  // Custom icon mappings for icon syntax
  icons?: Record<string, string>;
}

Note: ParseOptions fields are defined in the type but are not yet implemented in the current version. Passing any of these options has no effect — parse() ignores them. In particular:

{ validate: true } does not cause parse() to throw on invalid input.

{ position: true } does not add position data to AST nodes.

To validate an AST, call validate(ast) separately after parse(). See the validate() section below.

Return Value

Returns a DocumentNode representing the parsed wiremd document:

interface DocumentNode {
  type: 'document';
  version: string;
  meta: DocumentMeta;
  children: WiremdNode[];
  position?: Location;
}

Examples

Basic Usage

import { parse } from 'wiremd';

const ast = parse(`
## Contact Form

Name
[_____________________________]{required}

Email
[_____________________________]{type:email required}

[Submit]{.primary} [Cancel]
`);

console.log(ast.type); // 'document'
console.log(ast.children.length); // Number of top-level nodes

With Position Information

Note: The position option is not yet implemented. Passing { position: true } currently has no effect and nodes will not include position data.

Position information would be useful for error reporting and source mapping once implemented:

import { parse } from 'wiremd';

const ast = parse(`
## Login Form
[Button]
`);

// Position data is not yet populated by the parser
ast.children.forEach(node => {
  if (node.position) {
    console.log(`${node.type} at line ${node.position.start.line}`);
  }
});

With Validation

To validate an AST for structural errors, call validate() separately after parse(). The validate option on ParseOptions is not yet implemented and has no effect.

import { parse, validate } from 'wiremd';

const ast = parse(`
## My Wireframe
[Button]
`);

const errors = validate(ast);
if (errors.length > 0) {
  errors.forEach(error => console.error('Validation error:', error.message));
} else {
  console.log('AST is valid');
}

With Custom Icons

Note: The icons option is not yet implemented and has no effect.

import { parse } from 'wiremd';

const ast = parse(`
## Header
[home-icon] Home
[user-icon] Profile
`);

Strict Mode

Note: The strict option is not yet implemented and has no effect.

import { parse } from 'wiremd';

const ast = parse(`
## Title
[Button]
`);

Advanced Examples

Processing Multiple Files

import { parse } from 'wiremd';
import { readFileSync, readdirSync } from 'fs';
import { join } from 'path';

const wireframesDir = './wireframes';
const files = readdirSync(wireframesDir).filter(f => f.endsWith('.md'));

const asts = files.map(file => {
  const content = readFileSync(join(wireframesDir, file), 'utf-8');
  return {
    filename: file,
    ast: parse(content)
  };
});

console.log(`Parsed ${asts.length} wireframe files`);

Extract Metadata

import { parse } from 'wiremd';

const ast = parse(`
## My Wireframe
This is a description
`);

// Access document metadata
console.log('Title:', ast.meta.title);
console.log('Description:', ast.meta.description);
console.log('Theme:', ast.meta.theme);
console.log('Viewport:', ast.meta.viewport);

Parse and Analyze

import { parse } from 'wiremd';

const ast = parse(`
## Dashboard

[Search...]{type:search}

> Grid(3)
[Card 1]
[Card 2]
[Card 3]
`);

// Count different node types
function countNodeTypes(nodes: WiremdNode[]): Record<string, number> {
  const counts: Record<string, number> = {};

  function traverse(node: WiremdNode) {
    counts[node.type] = (counts[node.type] || 0) + 1;

    if ('children' in node && Array.isArray(node.children)) {
      node.children.forEach(traverse);
    }
  }

  nodes.forEach(traverse);
  return counts;
}

const counts = countNodeTypes(ast.children);
console.log('Node type counts:', counts);
// Output: { heading: 1, input: 1, grid: 1, container: 3, ... }

resolveIncludes()

Resolve ![[file.md]] include references in a Markdown string before parsing.

Signature

function resolveIncludes(markdown: string, basePath: string): string

Parameters

`markdown: string`

The Markdown source string, which may contain ![[relative/path.md]] include syntax.

`basePath: string`

The base path used to resolve relative include paths. Pass the directory of the file being processed (e.g. path.dirname(filePath)).

Return Value

Returns the Markdown string with every ![[relative/path.md]] reference replaced by the contents of the referenced file. Include patterns inside fenced code blocks or inline code spans are left untouched. If a referenced file cannot be found or read, the include is replaced with a blockquote warning comment.

When You Need It

If your input Markdown uses ![[file.md]] include syntax and you are calling parse() directly (not via the CLI), you must call resolveIncludes() first. The CLI runs resolveIncludes() automatically; the parse() library function does not.

Example

import { resolveIncludes, parse, renderToHTML } from 'wiremd';
import { readFileSync } from 'fs';
import path from 'path';

const filePath = './wireframes/dashboard.md';
const markdown = readFileSync(filePath, 'utf-8');

// Resolve includes before parsing
const resolved = resolveIncludes(markdown, path.dirname(filePath));
const ast = parse(resolved);
const html = renderToHTML(ast);

validate()

Validate a wiremd AST for structural correctness.

Signature

function validate(ast: DocumentNode): ValidationError[]

Parameters

`ast: DocumentNode`

The wiremd AST to validate.

Return Value

Returns an array of ValidationError objects. An empty array indicates the AST is valid.

interface ValidationError {
  message: string;
  path?: string[];
  code?: string;
}

Examples

Basic Validation

import { parse, validate } from 'wiremd';

const ast = parse(`
## Contact Form
[Submit]
`);

const errors = validate(ast);

if (errors.length === 0) {
  console.log('AST is valid');
} else {
  errors.forEach(error => {
    console.error(`Error: ${error.message}`);
    if (error.code) {
      console.error(`  Code: ${error.code}`);
    }
    if (error.path) {
      console.error(`  Path: ${error.path.join(' > ')}`);
    }
  });
}

Pre-render Validation

import { parse, validate, renderToHTML } from 'wiremd';

const markdown = `
## My Wireframe
[Button]
`;

const ast = parse(markdown);
const errors = validate(ast);

if (errors.length > 0) {
  throw new Error(`Cannot render invalid AST: ${errors[0].message}`);
}

const html = renderToHTML(ast);

Custom Validation Rules

import { parse, validate } from 'wiremd';

function validateCustomRules(ast: DocumentNode): string[] {
  const warnings: string[] = [];

  // First run standard validation
  const errors = validate(ast);
  if (errors.length > 0) {
    return errors.map(e => e.message);
  }

  // Add custom validation rules
  function traverse(node: WiremdNode, depth: number = 0) {
    // Example: Warn about deeply nested structures
    if (depth > 5) {
      warnings.push(`Deep nesting detected at ${node.type} (depth: ${depth})`);
    }

    // Example: Warn about missing button labels
    if (node.type === 'button' && !node.content && !node.children) {
      warnings.push('Button without label detected');
    }

    if ('children' in node && Array.isArray(node.children)) {
      node.children.forEach(child => traverse(child, depth + 1));
    }
  }

  ast.children.forEach(child => traverse(child));
  return warnings;
}

const ast = parse(`## Form\n[Button]`);
const warnings = validateCustomRules(ast);
warnings.forEach(w => console.warn(w));

Error Handling

parse() is resilient and does not throw on most malformed input — it parses what it can and returns an AST. To check whether the result is structurally valid, call validate(ast) after parsing. The validate option on ParseOptions is not yet implemented and has no effect.

import { parse, validate } from 'wiremd';

function parseUserInput(input: string): DocumentNode | null {
  // parse() itself rarely throws; validate() checks structural correctness
  const ast = parse(input);

  const errors = validate(ast);
  if (errors.length > 0) {
    console.error('Validation errors:');
    errors.forEach(error => console.error(`  - ${error.message}`));
    return null;
  }

  return ast;
}

const ast = parseUserInput('## My Wireframe\n[Button]');

Performance Considerations

Caching Parsed ASTs

For frequently used wireframes, consider caching parsed ASTs:

import { parse } from 'wiremd';

const astCache = new Map<string, DocumentNode>();

function getCachedAST(markdown: string): DocumentNode {
  const cacheKey = markdown; // Or use a hash for large documents

  if (!astCache.has(cacheKey)) {
    astCache.set(cacheKey, parse(markdown));
  }

  return astCache.get(cacheKey)!;
}

// First call parses
const ast1 = getCachedAST('## Form\n[Button]');

// Second call returns cached result
const ast2 = getCachedAST('## Form\n[Button]');

console.log(ast1 === ast2); // true

Incremental Parsing

For large documents, consider splitting into sections:

import { parse } from 'wiremd';

function parseInSections(markdown: string): DocumentNode[] {
  // Split by top-level headings
  const sections = markdown.split(/(?=^## )/gm).filter(s => s.trim());

  return sections.map(section => parse(section));
}

const largeMd = `
## Section 1
Content...

## Section 2
More content...
`;

const sectionASTs = parseInSections(largeMd);
console.log(`Parsed ${sectionASTs.length} sections`);

Interactive Examples

Try these examples in your browser:

Parse and Render Example - Parse markdown and render to HTML
AST Manipulation - Modify the AST programmatically
Validation Example - Validate wiremd documents

::: tip You can fork these examples and experiment with your own wiremd syntax! :::

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Parser API

parse()

Signature

Parameters

input: string

options?: ParseOptions

Return Value

Examples

Basic Usage

With Position Information

With Validation

With Custom Icons

Strict Mode

Advanced Examples

Processing Multiple Files

Extract Metadata

Parse and Analyze

resolveIncludes()

Signature

Parameters

markdown: string

basePath: string

Return Value

When You Need It

Example

validate()

Signature

Parameters

ast: DocumentNode

Return Value

Examples

Basic Validation

Pre-render Validation

Custom Validation Rules

Error Handling

Performance Considerations

Caching Parsed ASTs

Incremental Parsing

Interactive Examples

See Also

`input: string`

`options?: ParseOptions`

`markdown: string`

`basePath: string`

`ast: DocumentNode`