wip: add markdown-it-figcaption

2025-05-02 21:31:28 -05:00 · 2025-05-02 21:31:28 -05:00 · 26ddcbfa89
parent bcf0092dd8
commit 26ddcbfa89
1 changed files with 83 additions and 0 deletions
--- a/markdown-it-figcaption.js
+++ b/markdown-it-figcaption.js
@ -0,0 +1,83 @@
+export default function figcaptionPlugin(md) {
+  // Rule to identify images followed by italicized text for figcaption
+  function figcaptionRule(state) {
+    const tokens = state.tokens;
+    let figcaptionStartIndex = -1;
+
+    for (let i = 0; i < tokens.length; i++) {
+      // Check for paragraph containing only an image
+      if (
+        tokens[i].type === 'paragraph_open' &&
+        i + 2 < tokens.length &&
+        tokens[i + 1].type === 'inline' &&
+        tokens[i + 1].children &&
+        tokens[i + 1].children.length === 1 &&
+        tokens[i + 1].children[0].type === 'image' &&
+        tokens[i + 2].type === 'paragraph_close'
+      ) {
+        // Check if the next token is a paragraph starting with emphasis
+        if (
+          i + 5 < tokens.length &&
+          tokens[i + 3].type === 'paragraph_open' &&
+          tokens[i + 4].type === 'inline' &&
+          tokens[i + 4].children &&
+          tokens[i + 4].children.length > 0 &&
+          tokens[i + 4].children[0].type === 'em_open' &&
+          tokens[i + 5].type === 'paragraph_close'
+        ) {
+          figcaptionStartIndex = i + 3; // Start index of the caption paragraph
+
+          // --- Replace tokens ---
+
+          // 1. Change paragraph_open to figure_open
+          const figureOpen = new state.Token('figure_open', 'figure', 1);
+          tokens[i] = figureOpen; // Replace paragraph_open
+
+          // 2. Keep the inline token with the image as is (tokens[i+1])
+
+          // 3. Change paragraph_close to figcaption_open
+          const figcaptionOpen = new state.Token('figcaption_open', 'figcaption', 1);
+          tokens[i + 2] = figcaptionOpen; // Replace paragraph_close
+
+          // 4. Remove the caption's paragraph_open
+          tokens.splice(figcaptionStartIndex, 1); // Remove paragraph_open at i+3
+
+          // 5. Modify the caption's inline content: remove outer <em> tags
+          const captionInlineToken = tokens[figcaptionStartIndex]; // Now at index i+3 after splice
+          if (
+            captionInlineToken.children[0].type === 'em_open' &&
+            captionInlineToken.children[captionInlineToken.children.length - 1].type === 'em_close'
+          ) {
+            captionInlineToken.children.shift(); // Remove em_open
+            captionInlineToken.children.pop(); // Remove em_close
+          }
+          // Adjust level for caption content
+          captionInlineToken.level += 1;
+          captionInlineToken.children.forEach(child => { child.level += 1; });
+
+
+          // 6. Change the caption's paragraph_close to figcaption_close
+          const figcaptionClose = new state.Token('figcaption_close', 'figcaption', -1);
+          tokens[figcaptionStartIndex + 1] = figcaptionClose; // Replace paragraph_close (now at i+4)
+
+          // 7. Add figure_close after figcaption_close
+          const figureClose = new state.Token('figure_close', 'figure', -1);
+          tokens.splice(figcaptionStartIndex + 2, 0, figureClose); // Insert figure_close (at i+5)
+
+          // Adjust token index to skip the newly inserted/modified tokens
+          i += 6; // Move past the figure structure
+        }
+      }
+    }
+  }
+
+  md.core.ruler.after('inline', 'figcaption', figcaptionRule);
+
+  // Add renderer rules if they don't exist
+  md.renderer.rules.figure_open = md.renderer.rules.figure_open || function () { return '<figure>\n'; };
+  md.renderer.rules.figure_close = md.renderer.rules.figure_close || function () { return '</figure>\n'; };
+  md.renderer.rules.figcaption_open = md.renderer.rules.figcaption_open || function () { return '<figcaption>'; };
+  md.renderer.rules.figcaption_close = md.renderer.rules.figcaption_close || function () { return '</figcaption>\n'; };
+}
+
+