Massive restructure of plugin API

plug-api/lib/yaml_page.ts

@@ -0,0 +1,49 @@
+import { findNodeOfType, traverseTree } from "$sb/lib/tree.ts";
+import { markdown, space } from "$sb/silverbullet-syscall/mod.ts";
+import * as YAML from "yaml";
+
+export async function readYamlPage(
+  pageName: string,
+  allowedLanguages = ["yaml"],
+): Promise<any> {
+  const text = await space.readPage(pageName);
+  const tree = await markdown.parseMarkdown(text);
+  let data: any = {};
+
+  traverseTree(tree, (t): boolean => {
+    // Find a fenced code block
+    if (t.type !== "FencedCode") {
+      return false;
+    }
+    const codeInfoNode = findNodeOfType(t, "CodeInfo");
+    if (!codeInfoNode) {
+      return false;
+    }
+    if (!allowedLanguages.includes(codeInfoNode.children![0].text!)) {
+      return false;
+    }
+    const codeTextNode = findNodeOfType(t, "CodeText");
+    if (!codeTextNode) {
+      // Honestly, this shouldn't happen
+      return false;
+    }
+    const codeText = codeTextNode.children![0].text!;
+    try {
+      data = YAML.parse(codeText);
+    } catch (e: any) {
+      console.error("YAML Page parser error", e);
+      throw new Error(`YAML Error: ${e.message}`);
+    }
+    return true;
+  });
+
+  return data;
+}
+
+export async function writeYamlPage(
+  pageName: string,
+  data: any,
+): Promise<void> {
+  const text = YAML.stringify(data);
+  await space.writePage(pageName, "```yaml\n" + text + "\n```");
+}