src/field.js
"use strict";
module.exports = Field;
// extends ReflectionObject
var ReflectionObject = require("./object");
((Field.prototype = Object.create(ReflectionObject.prototype)).constructor = Field).className = "Field";
var Enum = require("./enum"),
types = require("./types"),
util = require("./util");
var Type; // cyclic
var ruleRe = /^required|optional|repeated$/;
/**
* Constructs a new message field instance. Note that {@link MapField|map fields} have their own class.
* @name Field
* @classdesc Reflected message field.
* @extends FieldBase
* @constructor
* @param {string} name Unique name within its namespace
* @param {number} id Unique id within its namespace
* @param {string} type Value type
* @param {string|Object.<string,*>} [rule="optional"] Field rule
* @param {string|Object.<string,*>} [extend] Extended type if different from parent
* @param {Object.<string,*>} [options] Declared options
*/
/**
* Constructs a field from a field descriptor.
* @param {string} name Field name
* @param {IField} json Field descriptor
* @returns {Field} Created field
* @throws {TypeError} If arguments are invalid
*/
Field.fromJSON = function fromJSON(name, json) {
return new Field(name, json.id, json.type, json.rule, json.extend, json.options, json.comment);
};
/**
* Not an actual constructor. Use {@link Field} instead.
* @classdesc Base class of all reflected message fields. This is not an actual class but here for the sake of having consistent type definitions.
* @exports FieldBase
* @extends ReflectionObject
* @constructor
* @param {string} name Unique name within its namespace
* @param {number} id Unique id within its namespace
* @param {string} type Value type
* @param {string|Object.<string,*>} [rule="optional"] Field rule
* @param {string|Object.<string,*>} [extend] Extended type if different from parent
* @param {Object.<string,*>} [options] Declared options
* @param {string} [comment] Comment associated with this field
*/
function Field(name, id, type, rule, extend, options, comment) {
if (util.isObject(rule)) {
comment = extend;
options = rule;
rule = extend = undefined;
} else if (util.isObject(extend)) {
comment = options;
options = extend;
extend = undefined;
}
ReflectionObject.call(this, name, options);
if (!util.isInteger(id) || id < 0)
throw TypeError("id must be a non-negative integer");
if (!util.isString(type))
throw TypeError("type must be a string");
if (rule !== undefined && !ruleRe.test(rule = rule.toString().toLowerCase()))
throw TypeError("rule must be a string rule");
if (extend !== undefined && !util.isString(extend))
throw TypeError("extend must be a string");
/**
* Field rule, if any.
* @type {string|undefined}
*/
if (rule === "proto3_optional") {
rule = "optional";
}
this.rule = rule && rule !== "optional" ? rule : undefined; // toJSON
/**
* Field type.
* @type {string}
*/
this.type = type; // toJSON
/**
* Unique field id.
* @type {number}
*/
this.id = id; // toJSON, marker
/**
* Extended type if different from parent.
* @type {string|undefined}
*/
this.extend = extend || undefined; // toJSON
/**
* Whether this field is required.
* @type {boolean}
*/
this.required = rule === "required";
/**
* Whether this field is optional.
* @type {boolean}
*/
this.optional = !this.required;
/**
* Whether this field is repeated.
* @type {boolean}
*/
this.repeated = rule === "repeated";
/**
* Whether this field is a map or not.
* @type {boolean}
*/
this.map = false;
/**
* Message this field belongs to.
* @type {Type|null}
*/
this.message = null;
/**
* OneOf this field belongs to, if any,
* @type {OneOf|null}
*/
this.partOf = null;
/**
* The field type's default value.
* @type {*}
*/
this.typeDefault = null;
/**
* The field's default value on prototypes.
* @type {*}
*/
this.defaultValue = null;
/**
* Whether this field's value should be treated as a long.
* @type {boolean}
*/
this.long = util.Long ? types.long[type] !== undefined : /* istanbul ignore next */ false;
/**
* Whether this field's value is a buffer.
* @type {boolean}
*/
this.bytes = type === "bytes";
/**
* Resolved type if not a basic type.
* @type {Type|Enum|null}
*/
this.resolvedType = null;
/**
* Sister-field within the extended type if a declaring extension field.
* @type {Field|null}
*/
this.extensionField = null;
/**
* Sister-field within the declaring namespace if an extended field.
* @type {Field|null}
*/
this.declaringField = null;
/**
* Internally remembers whether this field is packed.
* @type {boolean|null}
* @private
*/
this._packed = null;
/**
* Comment for this field.
* @type {string|null}
*/
this.comment = comment;
}
/**
* Determines whether this field is packed. Only relevant when repeated and working with proto2.
* @name Field#packed
* @type {boolean}
* @readonly
*/
Object.defineProperty(Field.prototype, "packed", {
get: function() {
// defaults to packed=true if not explicity set to false
if (this._packed === null)
this._packed = this.getOption("packed") !== false;
return this._packed;
}
});
/**
* @override
*/
Field.prototype.setOption = function setOption(name, value, ifNotSet) {
if (name === "packed") // clear cached before setting
this._packed = null;
return ReflectionObject.prototype.setOption.call(this, name, value, ifNotSet);
};
/**
* Field descriptor.
* @interface IField
* @property {string} [rule="optional"] Field rule
* @property {string} type Field type
* @property {number} id Field id
* @property {Object.<string,*>} [options] Field options
*/
/**
* Extension field descriptor.
* @interface IExtensionField
* @extends IField
* @property {string} extend Extended type
*/
/**
* Converts this field to a field descriptor.
* @param {IToJSONOptions} [toJSONOptions] JSON conversion options
* @returns {IField} Field descriptor
*/
Field.prototype.toJSON = function toJSON(toJSONOptions) {
var keepComments = toJSONOptions ? Boolean(toJSONOptions.keepComments) : false;
return util.toObject([
"rule" , this.rule !== "optional" && this.rule || undefined,
"type" , this.type,
"id" , this.id,
"extend" , this.extend,
"options" , this.options,
"comment" , keepComments ? this.comment : undefined
]);
};
/**
* Resolves this field's type references.
* @returns {Field} `this`
* @throws {Error} If any reference cannot be resolved
*/
Field.prototype.resolve = function resolve() {
if (this.resolved)
return this;
if ((this.typeDefault = types.defaults[this.type]) === undefined) { // if not a basic type, resolve it
this.resolvedType = (this.declaringField ? this.declaringField.parent : this.parent).lookupTypeOrEnum(this.type);
if (this.resolvedType instanceof Type)
this.typeDefault = null;
else // instanceof Enum
this.typeDefault = this.resolvedType.values[Object.keys(this.resolvedType.values)[0]]; // first defined
} else if (this.options && this.options.proto3_optional) {
// proto3 scalar value marked optional; should default to null
this.typeDefault = null;
}
// use explicitly set default value if present
if (this.options && this.options["default"] != null) {
this.typeDefault = this.options["default"];
if (this.resolvedType instanceof Enum && typeof this.typeDefault === "string")
this.typeDefault = this.resolvedType.values[this.typeDefault];
}
// remove unnecessary options
if (this.options) {
if (this.options.packed === true || this.options.packed !== undefined && this.resolvedType && !(this.resolvedType instanceof Enum))
delete this.options.packed;
if (!Object.keys(this.options).length)
this.options = undefined;
}
// convert to internal data type if necesssary
if (this.long) {
this.typeDefault = util.Long.fromNumber(this.typeDefault, this.type.charAt(0) === "u");
/* istanbul ignore else */
if (Object.freeze)
Object.freeze(this.typeDefault); // long instances are meant to be immutable anyway (i.e. use small int cache that even requires it)
} else if (this.bytes && typeof this.typeDefault === "string") {
var buf;
if (util.base64.test(this.typeDefault))
util.base64.decode(this.typeDefault, buf = util.newBuffer(util.base64.length(this.typeDefault)), 0);
else
util.utf8.write(this.typeDefault, buf = util.newBuffer(util.utf8.length(this.typeDefault)), 0);
this.typeDefault = buf;
}
// take special care of maps and repeated fields
if (this.map)
this.defaultValue = util.emptyObject;
else if (this.repeated)
this.defaultValue = util.emptyArray;
else
this.defaultValue = this.typeDefault;
// ensure proper value on prototype
if (this.parent instanceof Type)
this.parent.ctor.prototype[this.name] = this.defaultValue;
return ReflectionObject.prototype.resolve.call(this);
};
/**
* Decorator function as returned by {@link Field.d} and {@link MapField.d} (TypeScript).
* @typedef FieldDecorator
* @type {function}
* @param {Object} prototype Target prototype
* @param {string} fieldName Field name
* @returns {undefined}
*/
/**
* Field decorator (TypeScript).
* @name Field.d
* @function
* @param {number} fieldId Field id
* @param {"double"|"float"|"int32"|"uint32"|"sint32"|"fixed32"|"sfixed32"|"int64"|"uint64"|"sint64"|"fixed64"|"sfixed64"|"string"|"bool"|"bytes"|Object} fieldType Field type
* @param {"optional"|"required"|"repeated"} [fieldRule="optional"] Field rule
* @param {T} [defaultValue] Default value
* @returns {FieldDecorator} Decorator function
* @template T extends number | number[] | Long | Long[] | string | string[] | boolean | boolean[] | Uint8Array | Uint8Array[] | Buffer | Buffer[]
*/
Field.d = function decorateField(fieldId, fieldType, fieldRule, defaultValue) {
// submessage: decorate the submessage and use its name as the type
if (typeof fieldType === "function")
fieldType = util.decorateType(fieldType).name;
// enum reference: create a reflected copy of the enum and keep reuseing it
else if (fieldType && typeof fieldType === "object")
fieldType = util.decorateEnum(fieldType).name;
return function fieldDecorator(prototype, fieldName) {
util.decorateType(prototype.constructor)
.add(new Field(fieldName, fieldId, fieldType, fieldRule, { "default": defaultValue }));
};
};
/**
* Field decorator (TypeScript).
* @name Field.d
* @function
* @param {number} fieldId Field id
* @param {Constructor<T>|string} fieldType Field type
* @param {"optional"|"required"|"repeated"} [fieldRule="optional"] Field rule
* @returns {FieldDecorator} Decorator function
* @template T extends Message<T>
* @variation 2
*/
// like Field.d but without a default value
// Sets up cyclic dependencies (called in index-light)
Field._configure = function configure(Type_) {
Type = Type_;
};