loopback/lib/models/model.js

373 lines
9.3 KiB
JavaScript

/*!
* Module Dependencies.
*/
var registry = require('../registry');
var assert = require('assert');
var SharedClass = require('strong-remoting').SharedClass;
/**
* The base class for **all models**.
*
* **Inheriting from `Model`**
*
* ```js
* var properties = {...};
* var options = {...};
* var MyModel = loopback.Model.extend('MyModel', properties, options);
* ```
*
* **Options**
*
* - `trackChanges` - If true, changes to the model will be tracked. **Required
* for replication.**
*
* **Events**
*
* #### Event: `changed`
*
* Emitted after a model has been successfully created, saved, or updated.
*
* ```js
* MyModel.on('changed', function(inst) {
* console.log('model with id %s has been changed', inst.id);
* // => model with id 1 has been changed
* });
* ```
*
* #### Event: `deleted`
*
* Emitted after an individual model has been deleted.
*
* ```js
* MyModel.on('deleted', function(inst) {
* console.log('model with id %s has been deleted', inst.id);
* // => model with id 1 has been deleted
* });
* ```
*
* #### Event: `deletedAll`
*
* Emitted after an individual model has been deleted.
*
* ```js
* MyModel.on('deletedAll', function(where) {
* if(where) {
* console.log('all models where', where, 'have been deleted');
* // => all models where
* // => {price: {gt: 100}}
* // => have been deleted
* }
* });
* ```
*
* #### Event: `attached`
*
* Emitted after a `Model` has been attached to an `app`.
*
* #### Event: `dataSourceAttached`
*
* Emitted after a `Model` has been attached to a `DataSource`.
*
* @class
* @param {Object} data
* @property {String} modelName The name of the model
* @property {DataSource} dataSource
*/
var Model = module.exports = registry.modelBuilder.define('Model');
/*!
* Called when a model is extended.
*/
Model.setup = function () {
var ModelCtor = this;
var options = this.settings;
// create a sharedClass
var sharedClass = ModelCtor.sharedClass = new SharedClass(
ModelCtor.modelName,
ModelCtor,
options.remoting
);
// support remoting prototype methods
ModelCtor.sharedCtor = function (data, id, fn) {
var ModelCtor = this;
if(typeof data === 'function') {
fn = data;
data = null;
id = null;
} else if (typeof id === 'function') {
fn = id;
if(typeof data !== 'object') {
id = data;
data = null;
} else {
id = null;
}
}
if(id && data) {
var model = new ModelCtor(data);
model.id = id;
fn(null, model);
} else if(data) {
fn(null, new ModelCtor(data));
} else if(id) {
ModelCtor.findById(id, function (err, model) {
if(err) {
fn(err);
} else if(model) {
fn(null, model);
} else {
err = new Error('could not find a model with id ' + id);
err.statusCode = 404;
fn(err);
}
});
} else {
fn(new Error('must specify an id or data'));
}
}
var idDesc = ModelCtor.modelName + ' id';
ModelCtor.sharedCtor.accepts = [
{arg: 'id', type: 'any', http: {source: 'path'}, description: idDesc}
// {arg: 'instance', type: 'object', http: {source: 'body'}}
];
ModelCtor.sharedCtor.http = [
{path: '/:id'}
];
ModelCtor.sharedCtor.returns = {root: true};
// before remote hook
ModelCtor.beforeRemote = function (name, fn) {
var self = this;
if(this.app) {
var remotes = this.app.remotes();
var className = self.modelName;
remotes.before(className + '.' + name, function (ctx, next) {
fn(ctx, ctx.result, next);
});
} else {
var args = arguments;
this.once('attached', function () {
self.beforeRemote.apply(self, args);
});
}
};
// after remote hook
ModelCtor.afterRemote = function (name, fn) {
var self = this;
if(this.app) {
var remotes = this.app.remotes();
var className = self.modelName;
remotes.after(className + '.' + name, function (ctx, next) {
fn(ctx, ctx.result, next);
});
} else {
var args = arguments;
this.once('attached', function () {
self.afterRemote.apply(self, args);
});
}
};
// resolve relation functions
sharedClass.resolve(function resolver(define) {
var relations = ModelCtor.relations;
if(!relations) return;
// get the relations
for(var relationName in relations) {
var relation = relations[relationName];
if(relation.type === 'belongsTo') {
ModelCtor.belongsToRemoting(relationName, relation, define)
} else {
ModelCtor.scopeRemoting(relationName, relation, define);
}
}
});
return ModelCtor;
};
/*!
* Get the reference to ACL in a lazy fashion to avoid race condition in require
*/
var _aclModel = null;
Model._ACL = function getACL(ACL) {
if(ACL !== undefined) {
// The function is used as a setter
_aclModel = ACL;
}
if(_aclModel) {
return _aclModel;
}
var aclModel = require('./acl').ACL;
_aclModel = registry.getModelByType(aclModel);
return _aclModel;
};
/**
* Check if the given access token can invoke the method
*
* @param {AccessToken} token The access token
* @param {*} modelId The model ID.
* @param {SharedMethod} sharedMethod The method in question
* @callback {Function} callback The callback function
* @param {String|Error} err The error object
* @param {Boolean} allowed True if the request is allowed; false otherwise.
*/
Model.checkAccess = function(token, modelId, sharedMethod, callback) {
var ANONYMOUS = require('./access-token').ANONYMOUS;
token = token || ANONYMOUS;
var aclModel = Model._ACL();
aclModel.checkAccessForContext({
accessToken: token,
model: this,
property: sharedMethod.name,
method: sharedMethod.name,
sharedMethod: sharedMethod,
modelId: modelId,
accessType: this._getAccessTypeForMethod(sharedMethod)
}, function(err, accessRequest) {
if(err) return callback(err);
callback(null, accessRequest.isAllowed());
});
};
/*!
* Determine the access type for the given `RemoteMethod`.
*
* @api private
* @param {RemoteMethod} method
*/
Model._getAccessTypeForMethod = function(method) {
if(typeof method === 'string') {
method = {name: method};
}
assert(
typeof method === 'object',
'method is a required argument and must be a RemoteMethod object'
);
var ACL = Model._ACL();
switch(method.name) {
case'create':
return ACL.WRITE;
case 'updateOrCreate':
return ACL.WRITE;
case 'upsert':
return ACL.WRITE;
case 'exists':
return ACL.READ;
case 'findById':
return ACL.READ;
case 'find':
return ACL.READ;
case 'findOne':
return ACL.READ;
case 'destroyById':
return ACL.WRITE;
case 'deleteById':
return ACL.WRITE;
case 'removeById':
return ACL.WRITE;
case 'count':
return ACL.READ;
default:
return ACL.EXECUTE;
}
}
/**
* Get the `Application` the Model is attached to.
*
* @callback {Function} callback
* @param {Error} err
* @param {Application} app
* @end
*/
Model.getApp = function(callback) {
var Model = this;
if(this.app) {
callback(null, this.app);
} else {
Model.once('attached', function() {
assert(Model.app);
callback(null, Model.app);
});
}
}
/**
* Enable remote invocation for the method with the given name.
*
* @param {String} name The name of the method.
* ```js
* // static method example (eg. Model.myMethod())
* Model.remoteMethod('myMethod');
* @param {Object} options The remoting options.
* See [loopback.remoteMethod()](http://docs.strongloop.com/display/DOC/Remote+methods+and+hooks#Remotemethodsandhooks-loopback.remoteMethod(fn,[options])) for details.
*/
Model.remoteMethod = function(name, options) {
if(options.isStatic === undefined) {
options.isStatic = true;
}
this.sharedClass.defineMethod(name, options);
}
Model.belongsToRemoting = function(relationName, relation, define) {
var fn = this.prototype[relationName];
define('__get__' + relationName, {
isStatic: false,
http: {verb: 'get', path: '/' + relationName},
accepts: {arg: 'refresh', type: 'boolean', http: {source: 'query'}},
description: 'Fetches belongsTo relation ' + relationName,
returns: {arg: relationName, type: relation.modelTo.modelName, root: true}
}, fn);
}
Model.scopeRemoting = function(relationName, relation, define) {
var toModelName = relation.modelTo.modelName;
define('__get__' + relationName, {
isStatic: false,
http: {verb: 'get', path: '/' + relationName},
accepts: {arg: 'filter', type: 'object'},
description: 'Queries ' + relationName + ' of ' + this.modelName + '.',
returns: {arg: relationName, type: [toModelName], root: true}
});
define('__create__' + relationName, {
isStatic: false,
http: {verb: 'post', path: '/' + relationName},
accepts: {arg: 'data', type: 'object', http: {source: 'body'}},
description: 'Creates a new instance in ' + relationName + ' of this model.',
returns: {arg: 'data', type: toModelName, root: true}
});
define('__delete__' + relationName, {
isStatic: false,
http: {verb: 'delete', path: '/' + relationName},
description: 'Deletes all ' + relationName + ' of this model.'
});
}
// setup the initial model
Model.setup();