162 lines
4.3 KiB
JavaScript
162 lines
4.3 KiB
JavaScript
/**
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* HttpDataProxy interface
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*
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* Copyright (C) 2017 R-T Specialty, LLC.
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*
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* This file is part of the Liza Data Collection Framework.
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*
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* liza is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* @todo This is a deprecated system; remove.
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*/
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var AbstractClass = require( 'easejs' ).AbstractClass,
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EventEmitter = require( 'events' ).EventEmitter;
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/**
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* Abstract class providing the foundation for a data proxy
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*
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* Data proxies simply abstract the means to communicate with another data
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* source, such as a remote web server.
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*/
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module.exports = AbstractClass( 'HttpDataProxy' )
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.extend( EventEmitter,
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{
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/**
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* Triggered when data is received
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* @type {string}
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*/
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'const EVENT_RECEIVED': 'received',
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/**
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* Retrieves data using a HTTP GET request
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*
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* @param {string} url URL to request
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* @param {function( Object, * )} callback function to call when complete
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*
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* @return {HttpDataProxy} self
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*/
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'public get': function( url, callback )
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{
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var _self = this;
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this.getData( url, function( data, error )
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{
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_self._dataResponse( data, error, callback );
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});
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return this;
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},
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/**
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* Retrieves data using a HTTP POST request
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*
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* @param {string} url URL to request
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* @param {Object} postdata data to post
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* @param {function( Object, * )} callback function to call when complete
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*
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* @return {HttpDataProxy} self
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*/
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'public post': function( url, postdata, callback )
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{
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var _self = this;
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this.postData( url, postdata, function( data, error )
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{
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_self._dataResponse( data, error, callback );
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});
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return this;
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},
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/**
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* Called when a response is received from the server
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*
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* The callback is not called if the process is aborted.
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*
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* @param {Object} data data received from server
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* @param {Object} error error data, otherwise null
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*
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* @param {function( Object, * )} callback function to call to return
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* received data
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*
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* @return void
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*/
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'protected _dataResponse': function( data, error, callback )
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{
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var abort = false,
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event = {
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abort: function()
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{
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abort = true;
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}
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};
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this.emit( this.__self.$('EVENT_RECEIVED'), data, event );
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// if aborted, we don't want to call the callback
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if ( abort )
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{
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return;
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}
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if ( callback instanceof Function )
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{
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callback( data, error );
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}
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},
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/**
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* Permits subtype to retrieve data
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*
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* Subtypes should override this method to implement a method for retrieving
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* data
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*
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* @param {string} url URL to request
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* @param {function( Object, * )} callback function to call when complete
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*
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* @return {undefined}
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*/
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'abstract protected getData': [ 'url', 'callback' ],
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/**
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* Permits subtype to retrieve data
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*
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* Subtypes should override this method to implement a method for retrieving
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* data
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*
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* @param {string} url URL to request
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* @param {Object} data data to post
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* @param {function( Object, * )} callback function to call when complete
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*
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* @return {undefined}
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*/
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'abstract protected postData': [ 'url', 'data', 'callback' ],
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/**
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* Aborts all current requests
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*
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* @return {HttpDataProxy} self
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*/
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'abstract public abortAll': []
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} );
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