marked.use

docs/USING_PRO.md

@@ -2,6 +2,16 @@
 
 To champion the single-responsibility and open/closed principles, we have tried to make it relatively painless to extend marked. If you are looking to add custom functionality, this is the place to start.
 
+<h2 id="use">marked.use()</h2>
+
+`marked.use(options)` is the recommended way to extend marked. The options object can contain any [option](#/USING_ADVANCED.md#options) available in marked.
+
+The `renderer` and `tokenizer` options can be an object with functions that will be merged into the `renderer` and `tokenizer` respectively.
+
+The `renderer` and `tokenizer` functions can return false to fallback to the previous function.
+
+All other options will overwrite previously set options.
+
 <h2 id="renderer">The renderer</h2>
 
 The renderer defines the output of the parser.
@@ -12,24 +22,25 @@ The renderer defines the output of the parser.
 // Create reference instance
 const marked = require('marked');
 
-// Get reference
-const renderer = new marked.Renderer();
-
 // Override function
-renderer.heading = function(text, level) {
-  const escapedText = text.toLowerCase().replace(/[^\w]+/g, '-');
-
-  return `
-          <h${level}>
-            <a name="${escapedText}" class="anchor" href="#${escapedText}">
-              <span class="header-link"></span>
-            </a>
-            ${text}
-          </h${level}>`;
+const renderer = {
+  heading(text, level) {
+    const escapedText = text.toLowerCase().replace(/[^\w]+/g, '-');
+
+    return `
+            <h${level}>
+              <a name="${escapedText}" class="anchor" href="#${escapedText}">
+                <span class="header-link"></span>
+              </a>
+              ${text}
+            </h${level}>`;
+  }
 };
 
+marked.use({ renderer });
+
 // Run marked
-console.log(marked('# heading+', { renderer }));
+console.log(marked('# heading+'));
 ```
 
 **Output:**
@@ -99,30 +110,34 @@ The tokenizer defines how to turn markdown text into tokens.
 // Create reference instance
 const marked = require('marked');
 
-// Get reference
-const tokenizer = new marked.Tokenizer();
-const originalCodespan = tokenizer.codespan;
 // Override function
-tokenizer.codespan = function(src) {
-  const match = src.match(/\$+([^\$\n]+?)\$+/);
-  if (match) {
-    return {
-      type: 'codespan',
-      raw: match[0],
-      text: match[1].trim()
-    };
+const tokenizer = {
+  codespan(src) {
+    const match = src.match(/\$+([^\$\n]+?)\$+/);
+    if (match) {
+      return {
+        type: 'codespan',
+        raw: match[0],
+        text: match[1].trim()
+      };
+    }
+
+    // return false to use original codespan tokenizer
+    return false;
   }
-  return originalCodespan.apply(this, arguments);
 };
 
+marked.use({ tokenizer });
+
 // Run marked
-console.log(marked('$ latex code $', { tokenizer }));
+console.log(marked('$ latex code $\n\n` other code `'));
 ```
 
 **Output:**
 
 ```html
-<p><code>latext code</code></p>
+<p><code>latex code</code></p>
+<p><code>other code</code></p>
 ```
 
 ### Block level tokenizer methods

docs/index.html

@@ -154,6 +154,7 @@ <h1>Marked.js Documentation</h1>
                     <li>
                         <a href="#/USING_PRO.md">Extensibility</a>
                         <ul>
+                            <li><a href="#/USING_PRO.md#use">marked.use()</a></li>
                             <li><a href="#/USING_PRO.md#renderer">Renderer</a></li>
                             <li><a href="#/USING_PRO.md#tokenizer">Tokenizer</a></li>
                             <li><a href="#/USING_PRO.md#lexer">Lexer</a></li>

src/marked.js

@@ -127,6 +127,43 @@ marked.getDefaults = getDefaults;
 
 marked.defaults = defaults;
 
+/**
+ * Use Extension
+ */
+
+marked.use = function(extension) {
+  const opts = merge({}, extension);
+  if (extension.renderer) {
+    const renderer = marked.defaults.renderer || new Renderer();
+    for (const prop in extension.renderer) {
+      const prevRenderer = renderer[prop];
+      renderer[prop] = (...args) => {
+        let ret = extension.renderer[prop].apply(renderer, args);
+        if (ret === false) {
+          ret = prevRenderer.apply(renderer, args);
+        }
+        return ret;
+      };
+    }
+    opts.renderer = renderer;
+  }
+  if (extension.tokenizer) {
+    const tokenizer = marked.defaults.tokenizer || new Tokenizer();
+    for (const prop in extension.tokenizer) {
+      const prevTokenizer = tokenizer[prop];
+      tokenizer[prop] = (...args) => {
+        let ret = extension.tokenizer[prop].apply(tokenizer, args);
+        if (ret === false) {
+          ret = prevTokenizer.apply(tokenizer, args);
+        }
+        return ret;
+      };
+    }
+    opts.tokenizer = tokenizer;
+  }
+  marked.setOptions(opts);
+};
+
 /**
  * Expose
  */

test/unit/marked-spec.js

@@ -96,3 +96,136 @@ describe('inlineLexer', () => {
     expect(renderer.html).toHaveBeenCalledWith('<img alt="MY IMAGE" src="example.png" />');
   });
 });
+
+describe('use extension', () => {
+  it('should use renderer', () => {
+    const extension = {
+      renderer: {
+        paragraph(text) {
+          return 'extension';
+        }
+      }
+    };
+    spyOn(extension.renderer, 'paragraph').and.callThrough();
+    marked.use(extension);
+    const html = marked('text');
+    expect(extension.renderer.paragraph).toHaveBeenCalledWith('text');
+    expect(html).toBe('extension');
+  });
+
+  it('should use tokenizer', () => {
+    const extension = {
+      tokenizer: {
+        paragraph(text) {
+          return {
+            type: 'paragraph',
+            raw: text,
+            text: 'extension'
+          };
+        }
+      }
+    };
+    spyOn(extension.tokenizer, 'paragraph').and.callThrough();
+    marked.use(extension);
+    const html = marked('text');
+    expect(extension.tokenizer.paragraph).toHaveBeenCalledWith('text');
+    expect(html).toBe('<p>extension</p>\n');
+  });
+
+  it('should use options from extension', () => {
+    const extension = {
+      headerIds: false
+    };
+    marked.use(extension);
+    const html = marked('# heading');
+    expect(html).toBe('<h1>heading</h1>\n');
+  });
+
+  it('should use last extension function and not override others', () => {
+    const extension1 = {
+      renderer: {
+        paragraph(text) {
+          return 'extension1 paragraph\n';
+        },
+        html(html) {
+          return 'extension1 html\n';
+        }
+      }
+    };
+    const extension2 = {
+      renderer: {
+        paragraph(text) {
+          return 'extension2 paragraph\n';
+        }
+      }
+    };
+    marked.use(extension1);
+    marked.use(extension2);
+    const html = marked(`
+paragraph
+
+<html />
+
+# heading
+`);
+    expect(html).toBe('extension2 paragraph\nextension1 html\n<h1 id="heading">heading</h1>\n');
+  });
+
+  it('should use previous extension when returning false', () => {
+    const extension1 = {
+      renderer: {
+        paragraph(text) {
+          if (text !== 'original') {
+            return 'extension1 paragraph\n';
+          }
+          return false;
+        }
+      }
+    };
+    const extension2 = {
+      renderer: {
+        paragraph(text) {
+          if (text !== 'extension1' && text !== 'original') {
+            return 'extension2 paragraph\n';
+          }
+          return false;
+        }
+      }
+    };
+    marked.use(extension1);
+    marked.use(extension2);
+    const html = marked(`
+paragraph
+
+extension1
+
+original
+`);
+    expect(html).toBe('extension2 paragraph\nextension1 paragraph\n<p>original</p>\n');
+  });
+
+  it('should get options with this.options', () => {
+    const extension = {
+      renderer: {
+        heading: () => {
+          return this.options ? 'arrow options\n' : 'arrow no options\n';
+        },
+        html: function() {
+          return this.options ? 'function options\n' : 'function no options\n';
+        },
+        paragraph() {
+          return this.options ? 'shorthand options\n' : 'shorthand no options\n';
+        }
+      }
+    };
+    marked.use(extension);
+    const html = marked(`
+# heading
+
+<html />
+
+paragraph
+`);
+    expect(html).toBe('arrow no options\nfunction options\nshorthand options\n');
+  });
+});