@wordpress/interactivity/build/proxies/signals.js

Package that provides a standard and simple way to handle the frontend interactivity of Gutenberg blocks.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.PropSignal = void 0;
var _signals = require("@preact/signals");
var _registry = require("./registry");
var _scopes = require("../scopes");
var _namespaces = require("../namespaces");
var _utils = require("../utils");
/**
 * External dependencies
 */

/**
 * Internal dependencies
 */

/**
 * Identifier for property computeds not associated to any scope.
 */
const NO_SCOPE = {};

/**
 * Structure that manages reactivity for a property in a state object. It uses
 * signals to keep track of property value or getter modifications.
 */
class PropSignal {
  /**
   * Proxy that holds the property this PropSignal is associated with.
   */

  /**
   * Relation of computeds by scope. These computeds are read-only signals
   * that depend on whether the property is a value or a getter and,
   * therefore, can return different values depending on the scope in which
   * the getter is accessed.
   */

  /**
   * Signal with the value assigned to the related property.
   */

  /**
   * Signal with the getter assigned to the related property.
   */

  /**
   * Structure that manages reactivity for a property in a state object, using
   * signals to keep track of property value or getter modifications.
   *
   * @param owner Proxy that holds the property this instance is associated
   *              with.
   */
  constructor(owner) {
    this.owner = owner;
    this.computedsByScope = new WeakMap();
  }

  /**
   * Changes the internal value. If a getter was set before, it is set to
   * `undefined`.
   *
   * @param value New value.
   */
  setValue(value) {
    this.update({
      value
    });
  }

  /**
   * Changes the internal getter. If a value was set before, it is set to
   * `undefined`.
   *
   * @param getter New getter.
   */
  setGetter(getter) {
    this.update({
      get: getter
    });
  }

  /**
   * Returns the computed that holds the result of evaluating the prop in the
   * current scope.
   *
   * These computeds are read-only signals that depend on whether the property
   * is a value or a getter and, therefore, can return different values
   * depending on the scope in which the getter is accessed.
   *
   * @return Computed that depends on the scope.
   */
  getComputed() {
    const scope = (0, _scopes.getScope)() || NO_SCOPE;
    if (!this.valueSignal && !this.getterSignal) {
      this.update({});
    }
    if (!this.computedsByScope.has(scope)) {
      const callback = () => {
        const getter = this.getterSignal?.value;
        return getter ? getter.call(this.owner) : this.valueSignal?.value;
      };
      (0, _namespaces.setNamespace)((0, _registry.getNamespaceFromProxy)(this.owner));
      this.computedsByScope.set(scope, (0, _signals.computed)((0, _utils.withScope)(callback)));
      (0, _namespaces.resetNamespace)();
    }
    return this.computedsByScope.get(scope);
  }

  /**
   *  Updates the internal signals for the value and the getter of the
   *  corresponding prop.
   *
   * @param param0
   * @param param0.get   New getter.
   * @param param0.value New value.
   */
  update({
    get,
    value
  }) {
    if (!this.valueSignal) {
      this.valueSignal = (0, _signals.signal)(value);
      this.getterSignal = (0, _signals.signal)(get);
    } else if (value !== this.valueSignal.peek() || get !== this.getterSignal.peek()) {
      (0, _signals.batch)(() => {
        this.valueSignal.value = value;
        this.getterSignal.value = get;
      });
    }
  }
}
exports.PropSignal = PropSignal;
//# sourceMappingURL=signals.js.map