initial commit (it all starts here...)

2020-05-25 22:36:20 -07:00 · 2020-05-25 22:36:20 -07:00 · 9e9842dc8c
commit 9e9842dc8c
36 changed files with 4550 additions and 0 deletions
--- a/src/render.ts
+++ b/src/render.ts
@ -0,0 +1,85 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import { Element, HTMLElement } from "./component";
+
+const HTML_ESCAPES: { [char: string]: string } = {
+    "&": "&amp;",
+    "<": "&lt;",
+    ">": "&gt;",
+};
+
+const escapeHtml = (text: string): string =>
+    text.replace(/[&<>]/g, (t) => HTML_ESCAPES[t]);
+
+const escapeAttr = (text: string): string => text.replace(/"/g, "&quot;");
+
+const renderElement = (elem: Element): string => {
+    // Ignore null and true/false to support nicer JSX conditional syntax with
+    // &&, ||, !! operators.
+    if (elem == null || typeof elem === "boolean") {
+        return "";
+    }
+    if (typeof elem === "string") {
+        return escapeHtml(elem);
+    }
+
+    let output = "";
+    output += startTag(elem);
+    for (const child of elem.children) {
+        output += renderElement(child);
+    }
+    output += endTag(elem);
+    return output;
+};
+
+const startTag = (elem: HTMLElement): string => {
+    let output = `<${escapeHtml(elem.tag)}`;
+
+    for (const [attrName, attrValue] of Object.entries(elem.attributes)) {
+        // Handle boolean attributes with a false value by not outputting the
+        // attribute at all.
+        if (attrValue === false) {
+            continue;
+        }
+
+        let normalizedAttrName = escapeHtml(attrName.toLowerCase());
+        if (normalizedAttrName === "classname") {
+            normalizedAttrName = "class";
+        }
+        if (attrValue === true) {
+            output += ` ${normalizedAttrName}=""`;
+        } else {
+            output += ` ${normalizedAttrName}="${escapeAttr(
+                attrValue.toString()
+            )}"`;
+        }
+    }
+
+    output += ">";
+    return output;
+};
+
+const endTag = (elem: HTMLElement): string => `</${escapeHtml(elem.tag)}>`;
+
+/**
+ * Render a complete HTML page from an HTMLElement. Note that the root element
+ * must represent a valid HTML tag.
+ *
+ * @param rootElem HTML element representing the root of the document.
+ *
+ * @return Fully rendered HTML document as a string.
+ */
+export const renderPage = (rootElem: HTMLElement): string => {
+    if (rootElem.tag.toLowerCase() !== "html") {
+        throw new Error(
+            `attempted to render page with non-HTML root element ${rootElem.tag}`
+        );
+    }
+
+    let output = "<!DOCTYPE html>";
+    output += renderElement(rootElem);
+    return output;
+};