loopback-datasource-juggler/lib/schema.js

445 lines
12 KiB
JavaScript

/**
* Module dependencies
*/
var AbstractClass = require('./abstract-class').AbstractClass;
var util = require('util');
var path = require('path');
var fs = require('fs');
var existsSync = fs.existsSync || path.existsSync;
/**
* Export public API
*/
exports.Schema = Schema;
// exports.AbstractClass = AbstractClass;
/**
* Helpers
*/
var slice = Array.prototype.slice;
Schema.Text = function Text() {};
Schema.JSON = function JSON() {};
Schema.types = {};
Schema.registerType = function (type) {
this.types[type.name] = type;
};
Schema.registerType(Schema.Text);
Schema.registerType(Schema.JSON);
/**
* Schema - 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 Schema creation, waiting for connection callback
* ```
* var schema = new Schema('mysql', { database: 'myapp_test' });
* schema.define(...);
* schema.on('connected', function () {
* // work with database
* });
* ```
*/
function Schema(name, settings) {
var schema = this;
// just save everything we get
this.name = name;
this.settings = settings;
// Disconnected by default
this.connected = false;
// create blank models pool
this.models = {};
this.definitions = {};
// 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');
}
}
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));
};
util.inherits(Schema, require('events').EventEmitter);
/**
* 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 }
* });
* ```
*/
Schema.prototype.define = function defineClass(className, properties, settings) {
var schema = this;
var args = slice.call(arguments);
if (!className) throw new Error('Class name required');
if (args.length == 1) properties = {}, args.push(properties);
if (args.length == 2) settings = {}, args.push(settings);
settings = settings || {};
standartize(properties, settings);
// every class can receive hash of data as optional param
var NewClass = function ModelConstructor(data) {
if (!(this instanceof ModelConstructor)) {
return new ModelConstructor(data);
}
AbstractClass.call(this, data);
};
hiddenProperty(NewClass, 'schema', schema);
hiddenProperty(NewClass, 'modelName', className);
hiddenProperty(NewClass, 'cache', {});
hiddenProperty(NewClass, 'mru', []);
hiddenProperty(NewClass, 'relations', {});
// inherit AbstractClass methods
for (var i in AbstractClass) {
NewClass[i] = AbstractClass[i];
}
for (var j in AbstractClass.prototype) {
NewClass.prototype[j] = AbstractClass.prototype[j];
}
NewClass.getter = {};
NewClass.setter = {};
// store class in model pool
this.models[className] = NewClass;
this.definitions[className] = {
properties: properties,
settings: settings
};
// pass controll to adapter
this.adapter.define({
model: NewClass,
properties: properties,
settings: settings
});
NewClass.prototype.__defineGetter__('id', function () {
return this.__data.id;
});
properties.id = properties.id || { type: Number };
NewClass.forEachProperty = function (cb) {
Object.keys(properties).forEach(cb);
};
NewClass.registerProperty = function (attr) {
Object.defineProperty(NewClass.prototype, attr, {
get: function () {
if (NewClass.getter[attr]) {
return NewClass.getter[attr].call(this);
} else {
return this.__data[attr];
}
},
set: function (value) {
if (NewClass.setter[attr]) {
NewClass.setter[attr].call(this, value);
} else {
this.__data[attr] = value;
}
},
configurable: true,
enumerable: true
});
NewClass.prototype.__defineGetter__(attr + '_was', function () {
return this.__dataWas[attr];
});
Object.defineProperty(NewClass.prototype, '_' + attr, {
get: function () {
return this.__data[attr];
},
set: function (value) {
this.__data[attr] = value;
},
configurable: true,
enumerable: false
});
};
NewClass.forEachProperty(NewClass.registerProperty);
return NewClass;
};
function standartize(properties, settings) {
Object.keys(properties).forEach(function (key) {
var v = properties[key];
if (
typeof v === 'function' ||
typeof v === 'object' && v && v.constructor.name === 'Array'
) {
properties[key] = { type: v };
}
});
// TODO: add timestamps fields
// when present in settings: {timestamps: true}
// or {timestamps: {created: 'created_at', updated: false}}
// by default property names: createdAt, updatedAt
}
/**
* Define single property named `prop` on `model`
*
* @param {String} model - name of model
* @param {String} prop - name of propery
* @param {Object} params - property settings
*/
Schema.prototype.defineProperty = function (model, prop, params) {
this.definitions[model].properties[prop] = params;
this.models[model].registerProperty(prop);
if (this.adapter.defineProperty) {
this.adapter.defineProperty(model, prop, params);
}
};
/**
* Extend existing model with bunch of properties
*
* @param {String} model - name of model
* @param {Object} props - hash of properties
*
* Example:
*
* // Instead of doing this:
*
* // amend the content model with competition attributes
* db.defineProperty('Content', 'competitionType', { type: String });
* db.defineProperty('Content', 'expiryDate', { type: Date, index: true });
* db.defineProperty('Content', 'isExpired', { type: Boolean, index: true });
*
* // schema.extend allows to
* // extend the content model with competition attributes
* db.extendModel('Content', {
* competitionType: String,
* expiryDate: { type: Date, index: true },
* isExpired: { type: Boolean, index: true }
* });
*/
Schema.prototype.extendModel = function (model, props) {
var t = this;
standartize(props, {});
Object.keys(props).forEach(function (propName) {
var definition = props[propName];
t.defineProperty(model, propName, definition);
});
};
/**
* 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.
*/
Schema.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.
*/
Schema.prototype.autoupdate = function (cb) {
this.freeze();
if (this.adapter.autoupdate) {
this.adapter.autoupdate(cb);
} else if (cb) {
cb();
}
};
/**
* Check whether migrations needed
* This method make sense only for sql adapters.
*/
Schema.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
*/
Schema.prototype.log = function (sql, t) {
this.emit('log', sql, t);
};
/**
* Freeze schema. Behavior depends on adapter
*/
Schema.prototype.freeze = function freeze() {
if (this.adapter.freezeSchema) {
this.adapter.freezeSchema();
}
}
/**
* Return table name for specified `modelName`
* @param {String} modelName
*/
Schema.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
*/
Schema.prototype.defineForeignKey = function defineForeignKey(className, key) {
// quit if key already defined
if (this.definitions[className].properties[key]) return;
if (this.adapter.defineForeignKey) {
this.adapter.defineForeignKey(className, key, function (err, keyType) {
if (err) throw err;
this.definitions[className].properties[key] = {type: keyType};
}.bind(this));
} else {
this.definitions[className].properties[key] = {type: Number};
}
this.models[className].registerProperty(key);
};
/**
* Close database connection
*/
Schema.prototype.disconnect = function disconnect() {
if (typeof this.adapter.disconnect === 'function') {
this.connected = false;
this.adapter.disconnect();
}
};
/**
* 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
});
}