Initial

resources/app/common/prosemirror/input-rules.mjs

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+import {ellipsis, InputRule, inputRules, textblockTypeInputRule, wrappingInputRule} from "prosemirror-inputrules";
+import ProseMirrorPlugin from "./plugin.mjs";
+
+/**
+ * A class responsible for building the input rules for the ProseMirror editor.
+ * @extends {ProseMirrorPlugin}
+ */
+export default class ProseMirrorInputRules extends ProseMirrorPlugin {
+  /**
+   * Build the plugin.
+   * @param {Schema} schema     The ProseMirror schema to build the plugin against.
+   * @param {object} [options]  Additional options to pass to the plugin.
+   * @param {number} [options.minHeadingLevel=0]  The minimum heading level to start from when generating heading input
+   *                                              rules. The resulting heading level for a heading rule is equal to the
+   *                                              number of leading hashes minus this number.
+   * */
+  static build(schema, {minHeadingLevel=0}={}) {
+    const rules = new this(schema, {minHeadingLevel});
+    return inputRules({rules: rules.buildRules()});
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Build input rules for node types present in the schema.
+   * @returns {InputRule[]}
+   */
+  buildRules() {
+    const rules = [ellipsis, ProseMirrorInputRules.#emDashRule()];
+    if ( "blockquote" in this.schema.nodes ) rules.push(this.#blockQuoteRule());
+    if ( "ordered_list" in this.schema.nodes ) rules.push(this.#orderedListRule());
+    if ( "bullet_list" in this.schema.nodes ) rules.push(this.#bulletListRule());
+    if ( "code_block" in this.schema.nodes ) rules.push(this.#codeBlockRule());
+    if ( "heading" in this.schema.nodes ) rules.push(this.#headingRule(1, 6));
+    if ( "horizontal_rule" in this.schema.nodes ) rules.push(this.#hrRule());
+    return rules;
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Turn a ">" at the start of a textblock into a blockquote.
+   * @returns {InputRule}
+   * @private
+   */
+  #blockQuoteRule() {
+    return wrappingInputRule(/^\s*>\s$/, this.schema.nodes.blockquote);
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Turn a number followed by a dot at the start of a textblock into an ordered list.
+   * @returns {InputRule}
+   * @private
+   */
+  #orderedListRule() {
+    return wrappingInputRule(
+      /^(\d+)\.\s$/, this.schema.nodes.ordered_list,
+      match => ({order: Number(match[1])}),
+      (match, node) => (node.childCount + node.attrs.order) === Number(match[1])
+    );
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Turn a -, +, or * at the start of a textblock into a bulleted list.
+   * @returns {InputRule}
+   * @private
+   */
+  #bulletListRule() {
+    return wrappingInputRule(/^\s*[-+*]\s$/, this.schema.nodes.bullet_list);
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Turn three backticks at the start of a textblock into a code block.
+   * @returns {InputRule}
+   * @private
+   */
+  #codeBlockRule() {
+    return textblockTypeInputRule(/^```$/, this.schema.nodes.code_block);
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Turns a double dash anywhere into an em-dash. Does not match at the start of the line to avoid conflict with the
+   * HR rule.
+   * @returns {InputRule}
+   * @private
+   */
+  static #emDashRule() {
+    return new InputRule(/[^-]+(--)/, "—");
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Turns a number of # characters followed by a space at the start of a textblock into a heading up to a maximum
+   * level.
+   * @param {number} minLevel  The minimum heading level to start generating input rules for.
+   * @param {number} maxLevel  The maximum number of heading levels.
+   * @returns {InputRule}
+   * @private
+   */
+  #headingRule(minLevel, maxLevel) {
+    const range = maxLevel - minLevel + 1;
+    return textblockTypeInputRule(
+      new RegExp(`^(#{1,${range}})\\s$`), this.schema.nodes.heading,
+      match => {
+        const level = match[1].length;
+        return {level: level + minLevel - 1};
+      }
+    );
+  }
+
+  /* -------------------------------------------- */
+
+  /**
+   * Turns three hyphens at the start of a line into a horizontal rule.
+   * @returns {InputRule}
+   * @private
+   */
+  #hrRule() {
+    const hr = this.schema.nodes.horizontal_rule;
+    return new InputRule(/^---$/, (state, match, start, end) => {
+      return state.tr.replaceRangeWith(start, end, hr.create()).scrollIntoView();
+    });
+  }
+}