Initial

resources/app/common/prosemirror/schema/schema-definition.mjs

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+/**
+ * An abstract interface for a ProseMirror schema definition.
+ * @abstract
+ */
+export default class SchemaDefinition {
+  /* -------------------------------------------- */
+  /*  Properties                                  */
+  /* -------------------------------------------- */
+
+  /**
+   * The HTML tag selector this node is associated with.
+   * @type {string}
+   */
+  static tag = "";
+
+  /* -------------------------------------------- */
+  /*  Methods                                     */
+  /* -------------------------------------------- */
+
+  /**
+   * Schema attributes.
+   * @returns {Record<string, AttributeSpec>}
+   * @abstract
+   */
+  static get attrs() {
+    throw new Error("SchemaDefinition subclasses must implement the attrs getter.");
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Check if an HTML element is appropriate to represent as this node, and if so, extract its schema attributes.
+   * @param {HTMLElement} el    The HTML element.
+   * @returns {object|boolean}  Returns false if the HTML element is not appropriate for this schema node, otherwise
+   *                            returns its attributes.
+   * @abstract
+   */
+  static getAttrs(el) {
+    throw new Error("SchemaDefinition subclasses must implement the getAttrs method.");
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Convert a ProseMirror Node back into an HTML element.
+   * @param {Node} node  The ProseMirror node.
+   * @returns {[string, any]}
+   * @abstract
+   */
+  static toDOM(node) {
+    throw new Error("SchemaDefinition subclasses must implement the toDOM method.");
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Create the ProseMirror schema specification.
+   * @returns {NodeSpec|MarkSpec}
+   * @abstract
+   */
+  static make() {
+    return {
+      attrs: this.attrs,
+      parseDOM: [{tag: this.tag, getAttrs: this.getAttrs.bind(this)}],
+      toDOM: this.toDOM.bind(this)
+    };
+  }
+}