Work on $share

2022-11-24 12:04:00 +01:00
parent c5c6cd3af0
commit 5b1ec14891
20 changed files with 528 additions and 163 deletions
@@ -0,0 +1,155 @@
+import * as YAML from "yaml";
+
+import {
+  addParentPointers,
+  findNodeOfType,
+  ParseTree,
+  renderToText,
+  replaceNodesMatching,
+  traverseTree,
+} from "$sb/lib/tree.ts";
+
+// Extracts front matter (or legacy "meta" code blocks) from a markdown document
+// optionally removes certain keys from the front matter
+export function extractFrontmatter(
+  tree: ParseTree,
+  removeKeys: string[] = [],
+): any {
+  let data: any = {};
+  addParentPointers(tree);
+
+  replaceNodesMatching(tree, (t) => {
+    // Find top-level hash tags
+    if (t.type === "Hashtag") {
+      // Check if if nested directly into a Paragraph
+      if (t.parent && t.parent.type === "Paragraph") {
+        const tagname = t.children![0].text!.substring(1);
+        if (!data.tags) {
+          data.tags = [];
+        }
+        if (!data.tags.includes(tagname)) {
+          data.tags.push(tagname);
+        }
+      }
+      return;
+    }
+    // Find FrontMatter and parse it
+    if (t.type === "FrontMatter") {
+      const yamlText = renderToText(t.children![1].children![0]);
+      try {
+        const parsedData: any = YAML.parse(yamlText);
+        const newData = { ...parsedData };
+        data = { ...data, ...parsedData };
+        if (removeKeys.length > 0) {
+          let removedOne = false;
+
+          for (const key of removeKeys) {
+            if (key in newData) {
+              delete newData[key];
+              removedOne = true;
+            }
+          }
+          if (removedOne) {
+            t.children![0].text = YAML.stringify(newData);
+          }
+        }
+        // If nothing is left, let's just delete this whole block
+        if (Object.keys(newData).length === 0) {
+          return null;
+        }
+      } catch (e: any) {
+        console.error("Could not parse frontmatter", e);
+      }
+    }
+
+    // Find a fenced code block with `meta` as the language type
+    if (t.type !== "FencedCode") {
+      return;
+    }
+    const codeInfoNode = findNodeOfType(t, "CodeInfo");
+    if (!codeInfoNode) {
+      return;
+    }
+    if (codeInfoNode.children![0].text !== "meta") {
+      return;
+    }
+    const codeTextNode = findNodeOfType(t, "CodeText");
+    if (!codeTextNode) {
+      // Honestly, this shouldn't happen
+      return;
+    }
+    const codeText = codeTextNode.children![0].text!;
+    const parsedData: any = YAML.parse(codeText);
+    const newData = { ...parsedData };
+    data = { ...data, ...parsedData };
+    if (removeKeys.length > 0) {
+      let removedOne = false;
+      for (const key of removeKeys) {
+        if (key in newData) {
+          delete newData[key];
+          removedOne = true;
+        }
+      }
+      if (removedOne) {
+        codeTextNode.children![0].text = YAML.stringify(newData).trim();
+      }
+    }
+    // If nothing is left, let's just delete this whole block
+    if (Object.keys(newData).length === 0) {
+      return null;
+    }
+
+    return undefined;
+  });
+
+  if (data.name) {
+    data.displayName = data.name;
+    delete data.name;
+  }
+
+  return data;
+}
+
+// Updates the front matter of a markdown document and returns the text as a rendered string
+export function prepareFrontmatterDispatch(
+  tree: ParseTree,
+  data: Record<string, any>,
+): any {
+  let dispatchData: any = null;
+  traverseTree(tree, (t) => {
+    // Find FrontMatter and parse it
+    if (t.type === "FrontMatter") {
+      const bodyNode = t.children![1].children![0];
+      const yamlText = renderToText(bodyNode);
+
+      try {
+        const parsedYaml = YAML.parse(yamlText) as any;
+        const newData = { ...parsedYaml, ...data };
+        // Patch inline
+        dispatchData = {
+          changes: {
+            from: bodyNode.from,
+            to: bodyNode.to,
+            insert: YAML.stringify(newData, { noArrayIndent: true }),
+          },
+        };
+      } catch (e: any) {
+        console.error("Error parsing YAML", e);
+      }
+      return true;
+    }
+    return false;
+  });
+  if (!dispatchData) {
+    // If we didn't find frontmatter, let's add it
+    dispatchData = {
+      changes: {
+        from: 0,
+        to: 0,
+        insert: "---\n" + YAML.stringify(data, { noArrayIndent: true }) +
+          "---\n",
+      },
+    };
+  }
+  return dispatchData;
+}