74 lines
2.0 KiB
JavaScript
74 lines
2.0 KiB
JavaScript
// Copyright IBM Corp. 2014,2016. All Rights Reserved.
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// Node module: loopback-datasource-juggler
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// This file is licensed under the MIT License.
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// License text available at https://opensource.org/licenses/MIT
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var debug = require('debug')('loopback:mixin');
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var assert = require('assert');
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var DefaultModelBaseClass = require('./model.js');
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function isModelClass(cls) {
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if (!cls) {
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return false;
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}
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return cls.prototype instanceof DefaultModelBaseClass;
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}
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module.exports = MixinProvider;
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function MixinProvider(modelBuilder) {
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this.modelBuilder = modelBuilder;
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this.mixins = {};
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}
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/**
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* Apply named mixin to the model class
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* @param {Model} modelClass
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* @param {String} name
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* @param {Object} options
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*/
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MixinProvider.prototype.applyMixin = function applyMixin(modelClass, name, options) {
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var fn = this.mixins[name];
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if (typeof fn === 'function') {
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if (modelClass.dataSource) {
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fn(modelClass, options || {});
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} else {
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modelClass.once('dataSourceAttached', function() {
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fn(modelClass, options || {});
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});
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}
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} else {
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// Try model name
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var model = this.modelBuilder.getModel(name);
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if (model) {
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debug('Mixin is resolved to a model: %s', name);
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modelClass.mixin(model, options);
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} else {
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var errMsg = 'Model "' + modelClass.modelName + '" uses unknown mixin: ' + name;
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debug(errMsg);
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throw new Error(errMsg);
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}
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}
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};
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/**
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* Define a mixin with name
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* @param {String} name Name of the mixin
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* @param {*) mixin The mixin function or a model
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*/
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MixinProvider.prototype.define = function defineMixin(name, mixin) {
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assert(typeof mixin === 'function', 'The mixin must be a function or model class');
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if (this.mixins[name]) {
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debug('Duplicate mixin: %s', name);
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} else {
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debug('Defining mixin: %s', name);
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}
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if (isModelClass(mixin)) {
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this.mixins[name] = function(Model, options) {
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Model.mixin(mixin, options);
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};
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} else if (typeof mixin === 'function') {
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this.mixins[name] = mixin;
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}
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};
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