src/root.js
"use strict";
module.exports = Root;
// extends Namespace
var Namespace = require("./namespace");
((Root.prototype = Object.create(Namespace.prototype)).constructor = Root).className = "Root";
var Field = require("./field"),
Enum = require("./enum"),
OneOf = require("./oneof"),
util = require("./util");
var Type, // cyclic
parse, // might be excluded
common; // "
/**
* Constructs a new root namespace instance.
* @classdesc Root namespace wrapping all types, enums, services, sub-namespaces etc. that belong together.
* @extends NamespaceBase
* @constructor
* @param {Object.<string,*>} [options] Top level options
*/
function Root(options) {
Namespace.call(this, "", options);
/**
* Deferred extension fields.
* @type {Field[]}
*/
this.deferred = [];
/**
* Resolved file names of loaded files.
* @type {string[]}
*/
this.files = [];
}
/**
* Loads a namespace descriptor into a root namespace.
* @param {INamespace} json Nameespace descriptor
* @param {Root} [root] Root namespace, defaults to create a new one if omitted
* @returns {Root} Root namespace
*/
Root.fromJSON = function fromJSON(json, root) {
if (!root)
root = new Root();
if (json.options)
root.setOptions(json.options);
return root.addJSON(json.nested);
};
/**
* Resolves the path of an imported file, relative to the importing origin.
* This method exists so you can override it with your own logic in case your imports are scattered over multiple directories.
* @function
* @param {string} origin The file name of the importing file
* @param {string} target The file name being imported
* @returns {string|null} Resolved path to `target` or `null` to skip the file
*/
Root.prototype.resolvePath = util.path.resolve;
/**
* Fetch content from file path or url
* This method exists so you can override it with your own logic.
* @function
* @param {string} path File path or url
* @param {FetchCallback} callback Callback function
* @returns {undefined}
*/
Root.prototype.fetch = util.fetch;
// A symbol-like function to safely signal synchronous loading
/* istanbul ignore next */
function SYNC() {} // eslint-disable-line no-empty-function
/**
* Loads one or multiple .proto or preprocessed .json files into this root namespace and calls the callback.
* @param {string|string[]} filename Names of one or multiple files to load
* @param {IParseOptions} options Parse options
* @param {LoadCallback} callback Callback function
* @returns {undefined}
*/
Root.prototype.load = function load(filename, options, callback) {
if (typeof options === "function") {
callback = options;
options = undefined;
}
var self = this;
if (!callback)
return util.asPromise(load, self, filename, options);
var sync = callback === SYNC; // undocumented
// Finishes loading by calling the callback (exactly once)
function finish(err, root) {
/* istanbul ignore if */
if (!callback)
return;
if (sync)
throw err;
var cb = callback;
callback = null;
cb(err, root);
}
// Bundled definition existence checking
function getBundledFileName(filename) {
var idx = filename.lastIndexOf("google/protobuf/");
if (idx > -1) {
var altname = filename.substring(idx);
if (altname in common) return altname;
}
return null;
}
// Processes a single file
function process(filename, source) {
try {
if (util.isString(source) && source.charAt(0) === "{")
source = JSON.parse(source);
if (!util.isString(source))
self.setOptions(source.options).addJSON(source.nested);
else {
parse.filename = filename;
var parsed = parse(source, self, options),
resolved,
i = 0;
if (parsed.imports)
for (; i < parsed.imports.length; ++i)
if (resolved = getBundledFileName(parsed.imports[i]) || self.resolvePath(filename, parsed.imports[i]))
fetch(resolved);
if (parsed.weakImports)
for (i = 0; i < parsed.weakImports.length; ++i)
if (resolved = getBundledFileName(parsed.weakImports[i]) || self.resolvePath(filename, parsed.weakImports[i]))
fetch(resolved, true);
}
} catch (err) {
finish(err);
}
if (!sync && !queued)
finish(null, self); // only once anyway
}
// Fetches a single file
function fetch(filename, weak) {
filename = getBundledFileName(filename) || filename;
// Skip if already loaded / attempted
if (self.files.indexOf(filename) > -1)
return;
self.files.push(filename);
// Shortcut bundled definitions
if (filename in common) {
if (sync)
process(filename, common[filename]);
else {
++queued;
setTimeout(function() {
--queued;
process(filename, common[filename]);
});
}
return;
}
// Otherwise fetch from disk or network
if (sync) {
var source;
try {
source = util.fs.readFileSync(filename).toString("utf8");
} catch (err) {
if (!weak)
finish(err);
return;
}
process(filename, source);
} else {
++queued;
self.fetch(filename, function(err, source) {
--queued;
/* istanbul ignore if */
if (!callback)
return; // terminated meanwhile
if (err) {
/* istanbul ignore else */
if (!weak)
finish(err);
else if (!queued) // can't be covered reliably
finish(null, self);
return;
}
process(filename, source);
});
}
}
var queued = 0;
// Assembling the root namespace doesn't require working type
// references anymore, so we can load everything in parallel
if (util.isString(filename))
filename = [ filename ];
for (var i = 0, resolved; i < filename.length; ++i)
if (resolved = self.resolvePath("", filename[i]))
fetch(resolved);
if (sync)
return self;
if (!queued)
finish(null, self);
return undefined;
};
// function load(filename:string, options:IParseOptions, callback:LoadCallback):undefined
/**
* Loads one or multiple .proto or preprocessed .json files into this root namespace and calls the callback.
* @function Root#load
* @param {string|string[]} filename Names of one or multiple files to load
* @param {LoadCallback} callback Callback function
* @returns {undefined}
* @variation 2
*/
// function load(filename:string, callback:LoadCallback):undefined
/**
* Loads one or multiple .proto or preprocessed .json files into this root namespace and returns a promise.
* @function Root#load
* @param {string|string[]} filename Names of one or multiple files to load
* @param {IParseOptions} [options] Parse options. Defaults to {@link parse.defaults} when omitted.
* @returns {Promise<Root>} Promise
* @variation 3
*/
// function load(filename:string, [options:IParseOptions]):Promise<Root>
/**
* Synchronously loads one or multiple .proto or preprocessed .json files into this root namespace (node only).
* @function Root#loadSync
* @param {string|string[]} filename Names of one or multiple files to load
* @param {IParseOptions} [options] Parse options. Defaults to {@link parse.defaults} when omitted.
* @returns {Root} Root namespace
* @throws {Error} If synchronous fetching is not supported (i.e. in browsers) or if a file's syntax is invalid
*/
Root.prototype.loadSync = function loadSync(filename, options) {
if (!util.isNode)
throw Error("not supported");
return this.load(filename, options, SYNC);
};
/**
* @override
*/
Root.prototype.resolveAll = function resolveAll() {
if (this.deferred.length)
throw Error("unresolvable extensions: " + this.deferred.map(function(field) {
return "'extend " + field.extend + "' in " + field.parent.fullName;
}).join(", "));
return Namespace.prototype.resolveAll.call(this);
};
// only uppercased (and thus conflict-free) children are exposed, see below
var exposeRe = /^[A-Z]/;
/**
* Handles a deferred declaring extension field by creating a sister field to represent it within its extended type.
* @param {Root} root Root instance
* @param {Field} field Declaring extension field witin the declaring type
* @returns {boolean} `true` if successfully added to the extended type, `false` otherwise
* @inner
* @ignore
*/
function tryHandleExtension(root, field) {
var extendedType = field.parent.lookup(field.extend);
if (extendedType) {
var sisterField = new Field(field.fullName, field.id, field.type, field.rule, undefined, field.options);
//do not allow to extend same field twice to prevent the error
if (extendedType.get(sisterField.name)) {
return true;
}
sisterField.declaringField = field;
field.extensionField = sisterField;
extendedType.add(sisterField);
return true;
}
return false;
}
/**
* Called when any object is added to this root or its sub-namespaces.
* @param {ReflectionObject} object Object added
* @returns {undefined}
* @private
*/
Root.prototype._handleAdd = function _handleAdd(object) {
if (object instanceof Field) {
if (/* an extension field (implies not part of a oneof) */ object.extend !== undefined && /* not already handled */ !object.extensionField)
if (!tryHandleExtension(this, object))
this.deferred.push(object);
} else if (object instanceof Enum) {
if (exposeRe.test(object.name))
object.parent[object.name] = object.values; // expose enum values as property of its parent
} else if (!(object instanceof OneOf)) /* everything else is a namespace */ {
if (object instanceof Type) // Try to handle any deferred extensions
for (var i = 0; i < this.deferred.length;)
if (tryHandleExtension(this, this.deferred[i]))
this.deferred.splice(i, 1);
else
++i;
for (var j = 0; j < /* initializes */ object.nestedArray.length; ++j) // recurse into the namespace
this._handleAdd(object._nestedArray[j]);
if (exposeRe.test(object.name))
object.parent[object.name] = object; // expose namespace as property of its parent
}
// The above also adds uppercased (and thus conflict-free) nested types, services and enums as
// properties of namespaces just like static code does. This allows using a .d.ts generated for
// a static module with reflection-based solutions where the condition is met.
};
/**
* Called when any object is removed from this root or its sub-namespaces.
* @param {ReflectionObject} object Object removed
* @returns {undefined}
* @private
*/
Root.prototype._handleRemove = function _handleRemove(object) {
if (object instanceof Field) {
if (/* an extension field */ object.extend !== undefined) {
if (/* already handled */ object.extensionField) { // remove its sister field
object.extensionField.parent.remove(object.extensionField);
object.extensionField = null;
} else { // cancel the extension
var index = this.deferred.indexOf(object);
/* istanbul ignore else */
if (index > -1)
this.deferred.splice(index, 1);
}
}
} else if (object instanceof Enum) {
if (exposeRe.test(object.name))
delete object.parent[object.name]; // unexpose enum values
} else if (object instanceof Namespace) {
for (var i = 0; i < /* initializes */ object.nestedArray.length; ++i) // recurse into the namespace
this._handleRemove(object._nestedArray[i]);
if (exposeRe.test(object.name))
delete object.parent[object.name]; // unexpose namespaces
}
};
// Sets up cyclic dependencies (called in index-light)
Root._configure = function(Type_, parse_, common_) {
Type = Type_;
parse = parse_;
common = common_;
};