update at 2025-09-22 13:55:41

src/markdown/footnote.ts

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2024-2025 Sun Booshi
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+import { Tokens, MarkedExtension } from "marked";
+import { Extension } from "./extension";
+
+const refRule = /^\[\^([^\]]+)\]/; // 匹配 [^label]
+const defRule = /^ *\[\^([^\]]+)\]:/; // 匹配 [^label]: 
+
+export class FootnoteRenderer extends Extension {
+  allDefs: any[] = [];
+  defCounter = 0;
+  async prepare() {
+    this.allDefs = [];
+    this.defCounter = 0;
+  }
+
+  async postprocess(html: string) {
+    if (this.allDefs.length == 0) {
+      return html;
+    }
+
+    let body  = '';
+    for (const def of this.allDefs) {
+      const {label, content} = def;
+      const html = await this.marked.parse(content);
+      const id = `fn-${label}`;
+      body += `<li id="${id}">${html}</li>`;
+    }
+    return html + `<section class="footnotes"><hr><ol>${body}</ol></section>`;
+  }
+
+  markedExtension(): MarkedExtension {
+    return {
+      extensions: [
+        {
+          name: 'FootnoteRef',
+          level: 'inline',
+          start(src) {
+            const index = src.indexOf('[^');
+            return index > 0 ? index : -1;
+          },
+          tokenizer: (src) => {
+            const match = src.match(refRule);
+            if (match) {
+              return {
+                type: 'FootnoteRef',
+                raw: match[0],
+                text: match[1],
+              };
+            }
+          },
+          renderer: (token: Tokens.Generic) => {
+            this.defCounter += 1;
+            const id = `fnref-${this.defCounter}`;
+            return `<sup id="${id}">${this.defCounter}</sup>`;
+          }
+        },
+        {
+          name: 'FootnoteDef',
+          level: 'block',
+          tokenizer: (src) => {
+            const match = src.match(defRule);
+            if (match) {
+              const label = match[1].trim();
+              const end = src.indexOf('\n');
+              const raw = end === -1 ? src: src.substring(0, end + 1);
+              const content = raw.substring(match[0].length);
+              this.allDefs.push({label, content});
+
+              return {
+                type: 'FootnoteDef',
+                raw: raw,
+                text: content,
+              };
+            }
+          },
+          renderer: (token: Tokens.Generic) => {
+            return '';
+          }
+        }
+      ]
+    }
+  }
+}