loopback-datasource-juggler/lib/datasource.js

497 lines
14 KiB
JavaScript

/**
* Module dependencies
*/
var ADL = require('./adl.js').Schema;
var ModelBaseClass = require('./model.js');
var DataAccessObject = require('./dao.js');
var List = require('./list.js');
var EventEmitter = require('events').EventEmitter;
var util = require('util');
var path = require('path');
var fs = require('fs');
var existsSync = fs.existsSync || path.existsSync;
/**
* Export public API
*/
exports.DataSource = DataSource;
/**
* Helpers
*/
var slice = Array.prototype.slice;
/**
* DataSource - adapter-specific classes factory.
*
* All classes in single schema shares same adapter type and
* one database connection
*
* @param name - type of schema adapter (mysql, mongoose, sequelize, redis)
* @param settings - any database-specific settings which we need to
* establish connection (of course it depends on specific adapter)
*
* - host
* - port
* - username
* - password
* - database
* - debug {Boolean} = false
*
* @example DataSource creation, waiting for connection callback
* ```
* var schema = new DataSource('mysql', { database: 'myapp_test' });
* schema.define(...);
* schema.on('connected', function () {
* // work with database
* });
* ```
*/
function DataSource(name, settings) {
if (!(this instanceof DataSource)) {
return new DataSource(name, settings);
}
ADL.call(this);
this.setup(name, settings);
};
util.inherits(DataSource, ADL);
// Copy over statics
for (var m in ADL) {
if (!DataSource[m]) {
DataSource[m] = ADL[m];
}
}
DataSource.prototype.setup = function(name, settings) {
var schema = this;
// just save everything we get
this.name = name;
this.settings = settings;
// Disconnected by default
this.connected = false;
this.connecting = false;
if (name) {
// and initialize schema using adapter
// this is only one initialization entry point of adapter
// this module should define `adapter` member of `this` (schema)
var adapter;
if (typeof name === 'object') {
adapter = name;
this.name = adapter.name;
} else if (name.match(/^\//)) {
// try absolute path
adapter = require(name);
} else if (existsSync(__dirname + '/adapters/' + name + '.js')) {
// try built-in adapter
adapter = require('./adapters/' + name);
} else {
// try foreign adapter
try {
adapter = require('jugglingdb-' + name);
} catch (e) {
return console.log('\nWARNING: JugglingDB adapter "' + name + '" is not installed,\nso your models would not work, to fix run:\n\n npm install jugglingdb-' + name, '\n');
}
}
}
if (adapter) {
adapter.initialize(this, function () {
// we have an adaper now?
if (!this.adapter) {
throw new Error('Adapter is not defined correctly: it should create `adapter` member of schema');
}
this.adapter.log = function (query, start) {
schema.log(query, start);
};
this.adapter.logger = function (query) {
var t1 = Date.now();
var log = this.log;
return function (q) {
log(q || query, t1);
};
};
this.connected = true;
this.emit('connected');
}.bind(this));
}
schema.connect = function(cb) {
var schema = this;
schema.connecting = true;
if (schema.adapter.connect) {
schema.adapter.connect(function(err) {
if (!err) {
schema.connected = true;
schema.connecting = false;
schema.emit('connected');
}
if (cb) {
cb(err);
}
});
} else {
if (cb) {
process.nextTick(cb);
}
}
};
}
/**
* Define class
*
* @param {String} className
* @param {Object} properties - hash of class properties in format
* `{property: Type, property2: Type2, ...}`
* or
* `{property: {type: Type}, property2: {type: Type2}, ...}`
* @param {Object} settings - other configuration of class
* @return newly created class
*
* @example simple case
* ```
* var User = schema.define('User', {
* email: String,
* password: String,
* birthDate: Date,
* activated: Boolean
* });
* ```
* @example more advanced case
* ```
* var User = schema.define('User', {
* email: { type: String, limit: 150, index: true },
* password: { type: String, limit: 50 },
* birthDate: Date,
* registrationDate: {type: Date, default: function () { return new Date }},
* activated: { type: Boolean, default: false }
* });
* ```
*/
DataSource.prototype.define = function defineClass(className, properties, settings) {
var NewClass = ADL.prototype.define.call(this, className, properties, settings);
// inherit DataAccessObject methods
for (var m in DataAccessObject) {
NewClass[m] = DataAccessObject[m];
}
for (var n in DataAccessObject.prototype) {
NewClass.prototype[n] = DataAccessObject.prototype[n];
}
if(this.adapter) {
// pass control to adapter
this.adapter.define({
model: NewClass,
properties: properties,
settings: settings
});
}
return NewClass;
};
/**
* Drop each model table and re-create.
* This method make sense only for sql adapters.
*
* @warning All data will be lost! Use autoupdate if you need your data.
*/
DataSource.prototype.automigrate = function (cb) {
this.freeze();
if (this.adapter.automigrate) {
this.adapter.automigrate(cb);
} else if (cb) {
cb();
}
};
/**
* Update existing database tables.
* This method make sense only for sql adapters.
*/
DataSource.prototype.autoupdate = function (cb) {
this.freeze();
if (this.adapter.autoupdate) {
this.adapter.autoupdate(cb);
} else if (cb) {
cb();
}
};
/**
* Discover existing database tables.
* This method returns an array of model objects, including {type, name, onwer}
*
* @param options An object that contains the following settings:
* all: true - Discovering all models, false - Discovering the models owned by the current user
* views: true - Including views, false - only tables
* limit: The page size
* offset: The starting index
*/
DataSource.prototype.discoverModels = function (options, cb) {
this.freeze();
if (this.adapter.discoverModels) {
this.adapter.discoverModels(options, cb);
} else if (cb) {
cb();
}
};
/**
* Discover properties for a given model.
* @param options An object that contains the following settings:
* model: The model name
* limit: The page size
* offset: The starting index
* The method return an array of properties, including {owner, tableName, columnName, dataType, dataLength, nullable}
*/
DataSource.prototype.discoverModelProperties = function (options, cb) {
this.freeze();
if (this.adapter.discoverModelProperties) {
this.adapter.discoverModelProperties(options, cb);
} else if (cb) {
cb();
}
};
/**
* Discover primary keys for a given owner/table
*
* Each primary key column description has the following columns:
* TABLE_SCHEM String => table schema (may be null)
* TABLE_NAME String => table name
* COLUMN_NAME String => column name
* KEY_SEQ short => sequence number within primary key( a value of 1 represents the first column of the primary key, a value of 2 would represent the second column within the primary key).
* PK_NAME String => primary key name (may be null)
*
* @param owner
* @param table
* @param cb
*/
DataSource.prototype.discoverPrimaryKeys= function(owner, table, cb) {
this.freeze();
if (this.adapter.discoverPrimaryKeys) {
this.adapter.discoverPrimaryKeys(owner, table, cb);
} else if (cb) {
cb();
}
}
/**
* Discover foreign keys for a given owner/table
*
* PKTABLE_SCHEM String => primary key table schema being imported (may be null)
* PKTABLE_NAME String => primary key table name being imported
* PKCOLUMN_NAME String => primary key column name being imported
* FKTABLE_CAT String => foreign key table catalog (may be null)
* FKTABLE_SCHEM String => foreign key table schema (may be null)
* FKTABLE_NAME String => foreign key table name
* FKCOLUMN_NAME String => foreign key column name
* KEY_SEQ short => sequence number within a foreign key( a value of 1 represents the first column of the foreign key, a value of 2 would represent the second column within the foreign key).
* FK_NAME String => foreign key name (may be null)
* PK_NAME String => primary key name (may be null)
*
* @param owner
* @param table
* @param cb
*/
DataSource.prototype.discoverForeignKeys= function(owner, table, cb) {
this.freeze();
if (this.adapter.discoverForeignKeys) {
this.adapter.discoverForeignKeys(owner, table, cb);
} else if (cb) {
cb();
}
}
/**
* Check whether migrations needed
* This method make sense only for sql adapters.
*/
DataSource.prototype.isActual = function (cb) {
this.freeze();
if (this.adapter.isActual) {
this.adapter.isActual(cb);
} else if (cb) {
cb(null, true);
}
};
/**
* Log benchmarked message. Do not redefine this method, if you need to grab
* chema logs, use `schema.on('log', ...)` emitter event
*
* @private used by adapters
*/
DataSource.prototype.log = function (sql, t) {
this.emit('log', sql, t);
};
/**
* Freeze schema. Behavior depends on adapter
*/
DataSource.prototype.freeze = function freeze() {
if (this.adapter.freezeSchema) {
this.adapter.freezeSchema();
}
}
/**
* Return table name for specified `modelName`
* @param {String} modelName
*/
DataSource.prototype.tableName = function (modelName) {
return this.definitions[modelName].settings.table = this.definitions[modelName].settings.table || modelName
};
/**
* Define foreign key
* @param {String} className
* @param {String} key - name of key field
*/
DataSource.prototype.defineForeignKey = function defineForeignKey(className, key, foreignClassName) {
// quit if key already defined
if (this.definitions[className].properties[key]) return;
if (this.adapter.defineForeignKey) {
var cb = function (err, keyType) {
if (err) throw err;
this.definitions[className].properties[key] = {type: keyType};
}.bind(this);
switch (this.adapter.defineForeignKey.length) {
case 4:
this.adapter.defineForeignKey(className, key, foreignClassName, cb);
break;
default:
case 3:
this.adapter.defineForeignKey(className, key, cb);
break;
}
} else {
this.definitions[className].properties[key] = {type: Number};
}
this.models[className].registerProperty(key);
};
/**
* Close database connection
*/
DataSource.prototype.disconnect = function disconnect(cb) {
if (typeof this.adapter.disconnect === 'function') {
this.connected = false;
this.adapter.disconnect(cb);
} else if (cb) {
cb();
}
};
DataSource.prototype.copyModel = function copyModel(Master) {
var schema = this;
var className = Master.modelName;
var md = Master.schema.definitions[className];
var Slave = function SlaveModel() {
Master.apply(this, [].slice.call(arguments));
this.schema = schema;
};
util.inherits(Slave, Master);
Slave.__proto__ = Master;
hiddenProperty(Slave, 'schema', schema);
hiddenProperty(Slave, 'modelName', className);
hiddenProperty(Slave, 'relations', Master.relations);
if (!(className in schema.models)) {
// store class in model pool
schema.models[className] = Slave;
schema.definitions[className] = {
properties: md.properties,
settings: md.settings
};
if (!schema.isTransaction) {
schema.adapter.define({
model: Slave,
properties: md.properties,
settings: md.settings
});
}
}
return Slave;
};
DataSource.prototype.transaction = function() {
var schema = this;
var transaction = new EventEmitter;
transaction.isTransaction = true;
transaction.origin = schema;
transaction.name = schema.name;
transaction.settings = schema.settings;
transaction.connected = false;
transaction.connecting = false;
transaction.adapter = schema.adapter.transaction();
// create blank models pool
transaction.models = {};
transaction.definitions = {};
for (var i in schema.models) {
schema.copyModel.call(transaction, schema.models[i]);
}
transaction.connect = schema.connect;
transaction.exec = function(cb) {
transaction.adapter.exec(cb);
};
return transaction;
};
/**
* Define hidden property
*/
function hiddenProperty(where, property, value) {
Object.defineProperty(where, property, {
writable: false,
enumerable: false,
configurable: false,
value: value
});
}
/**
* Define readonly property on object
*
* @param {Object} obj
* @param {String} key
* @param {Mixed} value
*/
function defineReadonlyProp(obj, key, value) {
Object.defineProperty(obj, key, {
writable: false,
enumerable: true,
configurable: true,
value: value
});
}