Added to/from xml helpers

src/xml.ts

@@ -0,0 +1,132 @@
+export function fromXml(xml: string) {
+	xml = xml.trim();
+	let pos = 0;
+
+	function parseNode(): any {
+		skipWhitespace();
+		if(xml[pos] !== '<') return parseText();
+		pos++; // skip <
+
+		if(xml[pos] === '?') {
+			parseDeclaration();
+			return parseNode();
+		}
+
+		if(xml[pos] === '!') {
+			parseComment();
+			return parseNode();
+		}
+
+		const tagName = parseTagName();
+		const attributes = parseAttributes();
+		skipWhitespace();
+
+		if(xml[pos] === '/' && xml[pos + 1] === '>') {
+			pos += 2; // skip />
+			return { tag: tagName, attributes, children: [] };
+		}
+
+		pos++; // skip >
+		const children = [];
+		while(pos < xml.length) {
+			skipWhitespace();
+			if(xml[pos] === '<' && xml[pos + 1] === '/') {
+				pos += 2; // skip </
+				parseTagName(); // skip closing tag name
+				skipWhitespace();
+				pos++; // skip >
+				break;
+			}
+			const child = parseNode();
+			if(child) children.push(child);
+		}
+		return { tag: tagName, attributes, children };
+	}
+
+	function parseTagName() {
+		let name = '';
+		while (pos < xml.length && /[a-zA-Z0-9_:-]/.test(xml[pos])) name += xml[pos++];
+		return name;
+	}
+
+	function parseAttributes() {
+		const attrs: any = {};
+		while (pos < xml.length) {
+			skipWhitespace();
+			if (xml[pos] === '>' || xml[pos] === '/') break;
+			const name = parseTagName();
+			skipWhitespace();
+			if (xml[pos] === '=') {
+				pos++;
+				skipWhitespace();
+				const quote = xml[pos++];
+				let value = '';
+				while (xml[pos] !== quote) value += xml[pos++];
+				pos++; // skip closing quote
+				attrs[name] = escapeXml(value, true);
+			}
+		}
+		return attrs;
+	}
+
+	function parseText() {
+		let text = '';
+		while (pos < xml.length && xml[pos] !== '<') text += xml[pos++];
+		text = text.trim();
+		return text ? escapeXml(text, true) : null;
+	}
+
+	function parseDeclaration() {
+		while (xml[pos] !== '>') pos++;
+		pos++;
+	}
+
+	function parseComment() {
+		while (!(xml[pos] === '-' && xml[pos + 1] === '-' && xml[pos + 2] === '>')) pos++;
+		pos += 3;
+	}
+
+	function skipWhitespace() {
+		while (pos < xml.length && /\s/.test(xml[pos])) pos++;
+	}
+
+	return parseNode();
+}
+
+export function toXml(obj: any, indent = '') {
+	if(typeof obj === 'string') return escapeXml(obj);
+	const { tag, attributes = {}, children = [] } = obj;
+	let xml = `${indent}<${tag}`;
+	for (const [key, value] of Object.entries(attributes))
+		xml += ` ${key}="${escapeXml(<any>value)}"`;
+	if (children.length === 0) {
+		xml += ' />';
+		return xml;
+	}
+	xml += '>';
+	const hasComplexChildren = children.some((c: any) => typeof c === 'object');
+	for (const child of children) {
+		if (hasComplexChildren) xml += '\n';
+		xml += toXml(child, hasComplexChildren ? indent + '  ' : '');
+	}
+	if(hasComplexChildren) xml += `\n${indent}`;
+	xml += `</${tag}>`;
+	return xml;
+}
+
+export function escapeXml(str: string, decode = false) {
+	if(decode) {
+		return str
+			.replace(/&lt;/g, '<')
+			.replace(/&gt;/g, '>')
+			.replace(/&quot;/g, '"')
+			.replace(/&apos;/g, "'")
+			.replace(/&amp;/g, '&');
+	}
+	return str
+		.replace(/&/g, '&amp;')
+		.replace(/</g, '&lt;')
+		.replace(/>/g, '&gt;')
+		.replace(/"/g, '&quot;')
+		.replace(/'/g, '&apos;');
+}