AsciiDoc to DocBook

1 files changed, 275 insertions, 0 deletions

diff --git a/nuldoc-src/docbook/to_html.ts b/nuldoc-src/docbook/to_html.ts
new file mode 100644
index 0000000..31c419d
--- /dev/null
+++ b/nuldoc-src/docbook/to_html.ts
@@ -0,0 +1,275 @@
+import { Document } from "./document.ts";
+import { DocBookError } from "../errors.ts";
+import {
+  Element,
+  findFirstChildElement,
+  forEachChild,
+  forEachChildRecursively,
+  Node,
+  removeChildElements,
+} from "../dom.ts";
+
+export default function toHtml(doc: Document): Document {
+  removeArticleInfo(doc);
+  removeArticleAttributes(doc);
+  removeUnnecessaryTextNode(doc);
+  transformElementNames(doc, "emphasis", "em");
+  transformElementNames(doc, "informaltable", "table");
+  transformElementNames(doc, "itemizedlist", "ul");
+  transformElementNames(doc, "link", "a");
+  transformElementNames(doc, "listitem", "li");
+  transformElementNames(doc, "literal", "code");
+  transformElementNames(doc, "orderedlist", "ol");
+  transformElementNames(doc, "simpara", "p");
+  transformAttributeNames(doc, "xml:id", "id");
+  transformSectionIdAttribute(doc);
+  setSectionTitleAnchor(doc);
+  transformSectionTitleElement(doc);
+  transformProgramListingElement(doc);
+  transformLiteralLayoutElement(doc);
+  transformNoteElement(doc);
+  setDefaultLangAttribute(doc);
+  traverseFootnotes(doc);
+  return doc;
+}
+
+function removeArticleInfo(doc: Document) {
+  const article = findFirstChildElement(doc.root, "article");
+  if (!article) {
+    throw new DocBookError(
+      `[docbook.tohtml] <article> element not found`,
+    );
+  }
+  removeChildElements(article, "info");
+}
+
+function removeArticleAttributes(doc: Document) {
+  const article = findFirstChildElement(doc.root, "article");
+  if (!article) {
+    throw new DocBookError(
+      `[docbook.tohtml] <article> element not found`,
+    );
+  }
+  article.attributes.delete("xmlns");
+  article.attributes.delete("xmlns:xl");
+  article.attributes.delete("version");
+}
+
+function removeUnnecessaryTextNode(doc: Document) {
+  const g = (n: Node) => {
+    if (n.kind !== "element") {
+      return;
+    }
+
+    let changed = true;
+    while (changed) {
+      changed = false;
+      if (n.children.length === 0) {
+        break;
+      }
+      const firstChild = n.children[0];
+      if (firstChild.kind === "text" && firstChild.content.trim() === "") {
+        n.children.shift();
+        changed = true;
+      }
+      if (n.children.length === 0) {
+        break;
+      }
+      const lastChild = n.children[n.children.length - 1];
+      if (lastChild.kind === "text" && lastChild.content.trim() === "") {
+        n.children.pop();
+        changed = true;
+      }
+    }
+
+    forEachChild(n, g);
+  };
+  forEachChild(doc.root, g);
+}
+
+function transformElementNames(
+  doc: Document,
+  from: string,
+  to: string,
+) {
+  forEachChildRecursively(doc.root, (n) => {
+    if (n.kind === "element" && n.name === from) {
+      n.name = to;
+    }
+  });
+}
+
+function transformAttributeNames(
+  doc: Document,
+  from: string,
+  to: string,
+) {
+  forEachChildRecursively(doc.root, (n) => {
+    if (n.kind !== "element") {
+      return;
+    }
+    const value = n.attributes.get(from) as string;
+    if (value !== undefined) {
+      n.attributes.delete(from);
+      n.attributes.set(to, value);
+    }
+  });
+}
+
+function transformSectionIdAttribute(doc: Document) {
+  forEachChildRecursively(doc.root, (n) => {
+    if (n.kind !== "element" || n.name !== "section") {
+      return;
+    }
+
+    const idAttr = n.attributes.get("id");
+    n.attributes.set("id", `section--${idAttr}`);
+  });
+}
+
+function setSectionTitleAnchor(doc: Document) {
+  const sectionStack: Element[] = [];
+  const g = (c: Node) => {
+    if (c.kind !== "element") {
+      return;
+    }
+
+    if (c.name === "section") {
+      sectionStack.push(c);
+    }
+    forEachChild(c, g);
+    if (c.name === "section") {
+      sectionStack.pop();
+    }
+    if (c.name === "title") {
+      const currentSection = sectionStack[sectionStack.length - 1];
+      if (!currentSection) {
+        throw new DocBookError(
+          "[docbook.tohtml] <title> element must be inside <section>",
+        );
+      }
+      const sectionId = currentSection.attributes.get("id");
+      const aElement: Element = {
+        kind: "element",
+        name: "a",
+        attributes: new Map(),
+        children: c.children,
+      };
+      aElement.attributes.set("href", `#${sectionId}`);
+      c.children = [aElement];
+    }
+  };
+  forEachChild(doc.root, g);
+}
+
+function transformSectionTitleElement(doc: Document) {
+  let sectionLevel = 1;
+  const g = (c: Node) => {
+    if (c.kind !== "element") {
+      return;
+    }
+
+    if (c.name === "section") {
+      sectionLevel += 1;
+      c.attributes.set("--section-level", sectionLevel.toString());
+    }
+    forEachChild(c, g);
+    if (c.name === "section") {
+      sectionLevel -= 1;
+    }
+    if (c.name === "title") {
+      c.name = `h${sectionLevel}`;
+    }
+  };
+  forEachChild(doc.root, g);
+}
+
+function transformProgramListingElement(doc: Document) {
+  forEachChildRecursively(doc.root, (n) => {
+    if (n.kind !== "element" || n.name !== "programlisting") {
+      return;
+    }
+
+    n.name = "pre";
+    const codeElement: Element = {
+      kind: "element",
+      name: "code",
+      attributes: new Map(),
+      children: n.children,
+    };
+    n.children = [codeElement];
+  });
+}
+
+function transformLiteralLayoutElement(doc: Document) {
+  forEachChildRecursively(doc.root, (n) => {
+    if (n.kind !== "element" || n.name !== "literallayout") {
+      return;
+    }
+
+    n.name = "pre";
+    const children = n.children;
+    const codeElement: Element = {
+      kind: "element",
+      name: "code",
+      attributes: new Map(),
+      children: children,
+    };
+    n.children = [codeElement];
+  });
+}
+
+function transformNoteElement(doc: Document) {
+  forEachChildRecursively(doc.root, (n) => {
+    if (n.kind !== "element" || n.name !== "note") {
+      return;
+    }
+
+    const labelElement: Element = {
+      kind: "element",
+      name: "div",
+      attributes: new Map(),
+      children: [{
+        kind: "text",
+        content: "Note",
+      }],
+    };
+    const contentElement: Element = {
+      kind: "element",
+      name: "div",
+      attributes: new Map(),
+      children: n.children,
+    };
+    n.name = "div";
+    n.children = [
+      labelElement,
+      contentElement,
+    ];
+  });
+}
+
+function setDefaultLangAttribute(_doc: Document) {
+  // TODO
+  // if (!e.attributes.has("lang")) {
+  //   e.attributes.set("lang", "ja-JP");
+  // }
+}
+
+function traverseFootnotes(doc: Document) {
+  forEachChildRecursively(doc.root, (n) => {
+    if (n.kind !== "element" || n.name !== "footnote") {
+      return;
+    }
+
+    // TODO
+    // <footnote>x</footnote>
+    //
+    // <sup class="footnote">[<a id="_footnoteref_1" class="footnote" href="#_footnotedef_1">1</a>]</sup>
+    //
+    // <div class="footnote" id="_footnotedef_1">
+    //   <a href="#_footnoteref_1">1</a>. RAS syndrome
+    // </div>
+    n.name = "span";
+    n.children = [];
+  });
+}