161 lines
4.2 KiB
JavaScript
161 lines
4.2 KiB
JavaScript
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/**
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* Data transmission over HTTP(S)
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*
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* Copyright (C) 2014 LoVullo Associates, Inc.
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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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var Class = require( 'easejs' ).Class,
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DataApi = require( '../DataApi' ),
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HttpImpl = require( './HttpImpl' ),
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// RFC 2616 methods
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rfcmethods = {
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DELETE: true,
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GET: true,
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HEAD: true,
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OPTIONS: true,
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POST: true,
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PUT: true,
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TRACE: true
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};
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/**
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* HTTP request abstraction. Does minor validation, but delegates to a specific
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* HTTP implementation for the actual request.
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*/
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module.exports = Class( 'HttpDataApi' )
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.implement( DataApi )
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.extend(
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{
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/**
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* Request URL
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* @type {string}
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*/
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'private _url': '',
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/**
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* HTTP method
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* @type {string}
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*/
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'private _method': '',
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/**
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* HTTP implementation to perfom request
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* @type {HttpImpl}
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*/
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'private _impl': null,
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/**
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* Initialize Data API with destination and HTTP implementation
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*
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* The supplied HTTP implementation will be used to perform the HTTP
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* requests, which permits the user to use whatever implementation works
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* well with their existing system.
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*
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* @param {string} url destination URL
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* @param {string} method RFC-2616-compliant HTTP method
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* @param {HttpImpl} impl HTTP implementation
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*
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* @throws {TypeError} when non-HttpImpl is provided
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*/
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__construct: function( url, method, impl )
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{
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if ( !( Class.isA( HttpImpl, impl ) ) )
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{
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throw TypeError( "Expected HttpImpl" );
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}
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this._url = ''+url;
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this._method = this._validateMethod( method );
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this._impl = impl;
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},
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/**
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* Perform an asynchronous request and invoke the callback with the reply
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*
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* In the event of an error, the first parameter is the error; otherwise, it
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* is null. The return data shall not be used in the event of an error.
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*
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* The return value shall be a raw string; conversion to other formats must
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* be handled by a wrapper.
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*
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* @param {string} data binary data to transmit
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* @param {function(?Error,*):string} callback continuation upon reply
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*
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* @return {DataApi} self
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*
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* @throws {TypeError} on validation failure
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*/
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'public request': function( data, callback )
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{
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this._validateDataType( data );
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this._impl.requestData(
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this._url, this._method, data, callback
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);
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return this;
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},
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/**
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* Ensures that the provided method conforms to RFC 2616
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*
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* @param {string} method HTTP method
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* @return {string} provided method
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*
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* @throws {Error} on non-conforming method
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*/
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'private _validateMethod': function( method )
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{
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if ( !( rfcmethods[ method ] ) )
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{
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throw Error( "Invalid RFC 2616 method: " + method );
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}
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return method;
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},
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/**
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* Validates that the provided data type is accepted by the Data API
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*
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* @param {*} data data to validate
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* @return {undefined}
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*
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* @throws {TypeError} on validation failure
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*/
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'private _validateDataType': function( data )
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{
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var type = typeof data;
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if ( ( data === null )
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|| !( ( type === 'string' ) || ( type === 'object' ) )
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)
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{
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throw TypeError(
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"Data must be a string of raw data or object containing " +
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"key-value params"
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);
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}
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}
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} );
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