Data wrapper class

src/data.js

@@ -0,0 +1,79 @@
+import xml2js from 'xml2js';
+
+class Data {
+	#obj;
+	#expression;
+
+	constructor(obj, expression) {
+		this.#obj = typeof obj === 'string' ? { _: obj } : obj;
+		this.#expression = expression;
+	}
+
+	get value() {
+		const value = this.#obj._;
+		if (value === undefined) {
+			throw new Error(`Could not get value from ${this.#expression}.`);
+		}
+
+		return value;
+	}
+
+	#buildExpression(propName, index) {
+		let expression = `${this.#expression}.${propName}`;
+		if (index !== undefined) {
+			expression += `[${index}]`;
+		}
+
+		return expression;
+	}
+
+	#getPropArray(propName, isRequired) {
+		const propArray = this.#obj[propName];
+		if (propArray === undefined && isRequired) {
+			throw new Error(`Could not find ${this.#buildExpression(propName)}.`);
+		}
+
+		return propArray;
+	}
+
+	getAll(propName, isRequired = true) {
+		const propArray = this.#getPropArray(propName, isRequired);
+		return propArray !== undefined ? propArray.map((value, index) => new Data(value, this.#buildExpression(propName, index))) : undefined;
+	}
+
+	getSingle(propName, index, isRequired = true) {
+		const prop = (this.#getPropArray(propName, isRequired) ?? [])[index];
+
+		if (prop === undefined && isRequired) {
+			throw new Error(`Could not find ${this.#buildExpression(propName, index)}.`)
+		}
+
+		return prop !== undefined ? new Data(prop, this.#buildExpression(propName, index)) : undefined;
+	}
+
+	getAttribute(attrName) {
+		const attribute = this.#obj.$?.[attrName];
+		if (attribute === undefined) {
+			throw new Error(`Could not get attribute ${attrName} from ${this.#expression}.`);
+		}
+
+		return attribute;
+	}
+}
+
+export async function load(content) {
+	const rootData = await xml2js.parseStringPromise(content, {
+		tagNameProcessors: [xml2js.processors.stripPrefix],
+		trim: true
+	}).catch((ex) => {
+		ex.message = 'Could not parse XML. This likely means your import file is malformed.\n\n' + ex.message;
+		throw ex;
+	});
+
+	const rssData = rootData.rss;
+	if (rssData === undefined) {
+		throw new Error('Could not find <rss> root node. This likely means your import file is malformed.')
+	}
+
+	return new Data(rssData, 'rss');
+}