extension_field_info.js

// Protocol Buffers - Google's data interchange format
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// https://protobuf.dev/
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/**
 * @fileoverview Definition of jspb.ExtensionFieldInfo.
 */

goog.module('jspb.ExtensionFieldInfo');
goog.module.declareLegacyNamespace();

// We need to reference jspb.Message for type annotations, but we want to avoid
// a circular dependency that would cause a runtime error.
goog.forwardDeclare('jspb.Message');

/**
 * Stores information for a single extension field.
 *
 * For example, an extension field defined like so:
 *
 *     extend BaseMessage {
 *       optional MyMessage my_field = 123;
 *     }
 *
 * will result in an ExtensionFieldInfo object with these properties:
 *
 *     {
 *       fieldIndex: 123,
 *       fieldName: {my_field_renamed: 0},
 *       ctor: proto.example.MyMessage,
 *       toObjectFn: proto.example.MyMessage.toObject,
 *       isRepeated: 0
 *     }
 *
 * We include `toObjectFn` to allow the JSCompiler to perform dead-code removal
 * on unused toObject() methods.
 *
 * If an extension field is primitive, ctor and toObjectFn will be null.
 * isRepeated should be 0 or 1.
 *
 * binary{Reader,Writer}Fn and (if message type) binaryMessageSerializeFn are
 * always provided. binaryReaderFn and binaryWriterFn are references to the
 * appropriate methods on BinaryReader/BinaryWriter to read/write the value of
 * this extension, and binaryMessageSerializeFn is a reference to the message
 * class's .serializeBinary method, if available.
 *
 * @param {number} fieldNumber
 * @param {Object} fieldName This has the extension field name as a property.
 * @param {?function(new: jspb.Message, Array=)} ctor
 * @param {?function((boolean|undefined),!jspb.Message):!Object} toObjectFn
 * @param {number} isRepeated
 * @constructor
 * @struct
 * @template T
 */
const ExtensionFieldInfo = function (
  fieldNumber, fieldName, ctor, toObjectFn, isRepeated) {
  /** @const */
  this.fieldIndex = fieldNumber;
  /** @const */
  this.fieldName = fieldName;
  /** @const */
  this.ctor = ctor;
  /** @const */
  this.toObjectFn = toObjectFn;
  /** @const */
  this.isRepeated = isRepeated;
};

/**
 * @return {boolean} Does this field represent a sub Message?
 * @export
 */
ExtensionFieldInfo.prototype.isMessageType = function () {
  return !!this.ctor;
};

exports = ExtensionFieldInfo;