Better auto initialization method for forms and resource displays

app/static/js/forms/index.js

@@ -3,15 +3,22 @@ var Forms = {};
 Forms.autoInit = () => {
   for (let propertyName in Forms) {
     let property = Forms[propertyName];
-    // Call the autoInit method of all properties that are subclasses of Forms.BaseForm
+    // Call autoInit of all properties that are subclasses of Forms.BaseForm.
+    // This does not include Forms.BaseForm itself.
     if (property.prototype instanceof Forms.BaseForm) {
-      property.autoInit();
+      // Check if the static htmlClass property is defined.
+      if (property.htmlClass === undefined) {return;}
+      // Gather all HTML elements that have the `this.htmlClass` class
+      // and do not have the no-autoinit class.
+      let formElements = document.querySelectorAll(`.${property.htmlClass}:not(.no-autoinit)`);
+      // Create an instance of this class for each form element.
+      for (let formElement of formElements) {new property(formElement);}
     }
   }
 };
 
 Forms.BaseForm = class BaseForm {
-  static autoInit() {throw 'Not implemented';}
+  static htmlClass;
 
   constructor(formElement) {
     this.formElement = formElement;