Add HtmlParser_.ts

src/HtmlParser_.ts

@@ -0,0 +1,53 @@
+// NOTE: Below class will be private in Google Apps Script.
+class HtmlParser_ {
+  // eslint-disable-next-line camelcase
+  private readonly element: GoogleAppsScript.XML_Service.Element
+
+  // eslint-disable-next-line camelcase
+  constructor (element: GoogleAppsScript.XML_Service.Element) {
+    this.element = element
+  }
+
+  // eslint-disable-next-line camelcase
+  getElementById (id: string): GoogleAppsScript.XML_Service.Element {
+    const descendantElements = this.getDescendantElements()
+    return descendantElements.filter(element => {
+      const idAttribute = element.getAttribute('id')
+      if (idAttribute == null) {
+        return false
+      }
+      const idAttributeValue = idAttribute.getValue()
+      return idAttributeValue === id
+    })[0]
+  }
+
+  // eslint-disable-next-line camelcase
+  getElementsByClassName (className: string): GoogleAppsScript.XML_Service.Element[] {
+    const descendantElements = this.getDescendantElements()
+    descendantElements.push(this.element)
+    return descendantElements.filter(element => {
+      const classAttribute = element.getAttribute('class')
+      if (classAttribute == null) {
+        return false
+      }
+      const classAttributeValue = classAttribute.getValue()
+      return (classAttributeValue === className) || (classAttributeValue.split(' ').some(name => name === className))
+    })
+  }
+
+  // eslint-disable-next-line camelcase
+  getElementsByTagName (tagName: string): GoogleAppsScript.XML_Service.Element[] {
+    const descendantElements = this.getDescendantElements()
+    return descendantElements.filter(element => element.getName() === tagName)
+  }
+
+  // eslint-disable-next-line camelcase
+  private getDescendantElements (): GoogleAppsScript.XML_Service.Element[] {
+    return this.element.getDescendants()
+      .map(content => content.asElement())
+      .filter(element => element != null)
+  }
+}
+
+// NOTE: Below statement will be removed by clasp.
+export default HtmlParser_