1 | |
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2 | // ----------------------------------------------------------------------------- |
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3 | // CLASS NanoAjax |
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4 | function NanoAjax() |
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5 | { |
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6 | /* Instance Variables */ |
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7 | |
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8 | // +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
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9 | // Public variables |
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10 | |
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11 | this.asynchronousMode = true; |
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12 | this.requestMethod = 'POST'; |
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13 | this.ajaxServerUrl = ''; |
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14 | |
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15 | this.statusTranslation = [ 'initializing...', |
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16 | 'connecting...', |
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17 | 'connection established', |
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18 | 'receiving data...', |
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19 | 'done.', |
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20 | 'decoding received data...', |
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21 | 'processing data...', |
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22 | 'done (processing)!' ]; |
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23 | |
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24 | this.onStateChangeId = null; |
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25 | |
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26 | this.errorReporting = true; |
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27 | this.disableExceptionReporting = false; |
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28 | |
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29 | // only needed if request method is set to: GET |
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30 | this.preparedGetData = ''; |
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31 | |
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32 | // ------------------------------------------------------------------------- |
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33 | // Private variables |
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34 | |
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35 | var _this = this; |
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36 | var _xmlHttpRequest = null; |
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37 | |
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38 | var _virtualRequest = new Object(); |
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39 | |
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40 | var _responseHeader = ''; |
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41 | var _responseBody = ''; |
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42 | |
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43 | |
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44 | // ######################################################################### |
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45 | // Privileged Method (has public access and can access private vars & funcs) |
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46 | |
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47 | // event handler |
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48 | this.onStateChange = null; |
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49 | this.onSuccess = null; |
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50 | this.onError = null; |
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51 | this.onException = null; |
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52 | |
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53 | // public accessable methods |
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54 | this.addVirtualRequest = _addVirtualRequest; |
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55 | this.isVirtualRequestSet = _isVirtualRequestSet; |
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56 | this.sendRequest = _executeRequest; |
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57 | |
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58 | |
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59 | // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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60 | // PRIVATE Methods |
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61 | |
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62 | /** |
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63 | * checks if virtual request is set |
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64 | * |
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65 | * @access private |
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66 | */ |
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67 | function _isVirtualRequestSet() |
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68 | { |
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69 | for ( virtualRequest in _virtualRequest ) |
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70 | { |
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71 | return true; |
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72 | } |
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73 | |
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74 | return false; |
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75 | } |
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76 | |
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77 | |
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78 | /** |
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79 | * executes real AJAX request |
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80 | * |
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81 | * @access private |
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82 | */ |
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83 | function _executeRequest() |
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84 | { |
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85 | _initializeXmlHttpRequest(); |
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86 | |
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87 | if( typeof _xmlHttpRequest == 'object' ) |
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88 | { |
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89 | this.requestMethod = this.requestMethod.toUpperCase(); |
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90 | |
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91 | _xmlHttpRequest.open( this.requestMethod, // POST or GET |
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92 | this.ajaxServerUrl + // full url to Ajax server |
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93 | this.preparedGetData, // with GET parameterdata |
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94 | this.asynchronousMode ); // true = async |
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95 | |
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96 | if( this.requestMethod == 'POST' ) |
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97 | { |
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98 | // set various header parameter |
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99 | _setPostRequestHeader(); |
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100 | } |
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101 | |
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102 | // set function if state changes (handler) |
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103 | _xmlHttpRequest.onreadystatechange = _readyStateHandler; |
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104 | |
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105 | // now realy send (execute) request to NanoAjax server (with JSON string) |
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106 | _xmlHttpRequest.send( JSON.stringify(_virtualRequest) ); |
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107 | |
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108 | // release object preventing memory leaks |
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109 | delete _xmlHttpRequest; |
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110 | } |
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111 | else |
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112 | { |
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113 | alert('ERROR while creating xmlhttprequest object!!!\n\n'+ |
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114 | 'Your System is not able to create a xmlhttprequest object!'); |
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115 | } |
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116 | } |
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117 | |
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118 | |
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119 | /** |
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120 | * ready state handler (called every time state changes) |
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121 | * |
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122 | * @access private |
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123 | */ |
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124 | function _readyStateHandler() |
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125 | { |
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126 | if( _this.onStateChange ) |
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127 | { |
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128 | _this.onStateChange( _xmlHttpRequest.readyState, |
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129 | _this.statusTranslation[_xmlHttpRequest.readyState], |
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130 | _this.onStateChangeId ); |
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131 | } |
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132 | |
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133 | try |
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134 | { |
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135 | if ( // request finished |
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136 | _xmlHttpRequest.readyState == 4 |
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137 | && // HTTP: OK HTTP: not modified |
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138 | ( _xmlHttpRequest.status == 200 || _xmlHttpRequest.status == 304 ) |
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139 | ) |
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140 | { |
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141 | _responseHeader = _xmlHttpRequest.getAllResponseHeaders(); |
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142 | _responseBody = _xmlHttpRequest.responseText; |
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143 | |
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144 | if( -1 == _checkPhpError( _responseBody ) ) |
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145 | { |
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146 | if( _this.onSuccess ) |
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147 | { |
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148 | var _json_decoded = _getJsonDecodedResponse(_responseBody); |
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149 | |
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150 | if( true == (exception_response = _checkServerException(_json_decoded)) ) |
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151 | { |
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152 | _this.onSuccess( _json_decoded ); |
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153 | } |
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154 | else |
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155 | { |
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156 | ( _this.onException ) |
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157 | ? _this.onException( _responseHeader, |
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158 | _responseBody, |
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159 | exception_response ) |
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160 | |
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161 | : _defaultErrorHandler( 'SERVER-SIDE EXCEPTION', |
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162 | exception_response ); |
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163 | } |
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164 | } |
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165 | else |
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166 | { |
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167 | alert( 'No \'onSuccess\' handler defined!!!\n\n'+_responseBody ); |
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168 | } |
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169 | } |
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170 | else |
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171 | { |
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172 | ( _this.onError ) |
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173 | ? _this.onError( _responseBody ) |
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174 | : _defaultErrorHandler( 'SERVER-SIDE ERROR', |
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175 | 'Request could NOT finished!!!' ); |
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176 | } |
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177 | |
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178 | _clearVirtualRequestData(); |
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179 | } |
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180 | } |
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181 | catch( exception ) |
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182 | { |
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183 | _clearVirtualRequestData(); |
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184 | |
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185 | ( _this.onError ) |
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186 | ? _this.onError( exception ) |
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187 | : _defaultErrorHandler( 'EXCEPTION', exception ); |
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188 | } |
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189 | } |
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190 | |
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191 | |
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192 | /** |
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193 | * initializing xmlhttprequest object by iterate over all given methods, |
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194 | * to find correct browser implementation. |
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195 | * |
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196 | * @access private |
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197 | */ |
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198 | function _initializeXmlHttpRequest() |
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199 | { |
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200 | if( _xmlHttpRequest == undefined || _xmlHttpRequest == null ) |
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201 | { |
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202 | _xmlHttpRequest = Try.these |
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203 | ( |
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204 | function() { return new ActiveXObject('Msxml2.XMLHTTP') }, |
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205 | function() { return new ActiveXObject('Microsoft.XMLHTTP')}, |
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206 | function() { return new XMLHttpRequest() } |
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207 | ) || false; |
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208 | } |
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209 | } |
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210 | |
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211 | |
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212 | /** |
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213 | * sets POST request header |
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214 | * |
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215 | * @access private |
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216 | */ |
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217 | function _setPostRequestHeader() |
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218 | { |
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219 | // set method, url and protocol / version |
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220 | _xmlHttpRequest.setRequestHeader( 'Method', |
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221 | this.requestMethod + ' ' + |
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222 | this.ajaxServerUrl + ' HTTP/1.1' ); |
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223 | |
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224 | // set content type for POST data |
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225 | _xmlHttpRequest.setRequestHeader( 'Content-Type', |
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226 | 'application/x-www-form-urlencoded' ); |
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227 | |
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228 | // close connection after transfer |
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229 | _xmlHttpRequest.setRequestHeader( 'Connection' , 'close' ); |
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230 | } |
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231 | |
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232 | |
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233 | /** |
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234 | * add a virtual request to request container (an object) |
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235 | * |
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236 | * @access private |
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237 | */ |
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238 | function _addVirtualRequest( requestIdentifier, requestObject ) |
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239 | { |
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240 | if( null != requestObject && undefined != requestObject ) |
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241 | { |
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242 | _virtualRequest[requestIdentifier] = requestObject; |
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243 | } |
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244 | } |
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245 | |
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246 | |
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247 | /** |
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248 | * checks for server side PHP errors |
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249 | * |
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250 | * @access private |
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251 | */ |
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252 | function _checkPhpError( response_string ) |
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253 | { |
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254 | return (response_string.toLowerCase()).search(/((parse|fatal) error)|(fatal|warning|notice)/); |
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255 | } |
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256 | |
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257 | |
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258 | /** |
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259 | * checks for server side PHP exceptions |
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260 | * |
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261 | * @access private |
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262 | */ |
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263 | function _checkServerException( decoded_json_data ) |
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264 | { |
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265 | var request_exception = new Array(); |
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266 | |
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267 | for( var requestIdentifier in decoded_json_data) |
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268 | { |
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269 | if( decoded_json_data[requestIdentifier]['exception'] ) |
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270 | { |
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271 | request_exception.push('Exception happend in (virtual) request : '+ |
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272 | requestIdentifier+' {request identifier}\n'+ |
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273 | decoded_json_data[requestIdentifier]['exception'] ); |
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274 | } |
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275 | } |
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276 | |
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277 | return (request_exception.length > 0 ) |
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278 | ? request_exception.join('\n') |
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279 | : true; |
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280 | } |
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281 | |
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282 | |
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283 | /** |
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284 | * default error handler (if none is specified) |
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285 | * |
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286 | * @access private |
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287 | */ |
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288 | function _defaultErrorHandler( type_header, message ) |
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289 | { |
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290 | if( true == this.errorReporting ) |
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291 | { |
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292 | alert( 'NanoAjax Class: '+type_header+' !!!\n'+ |
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293 | ('=').repeat(54)+ '\n'+ |
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294 | '\n'+message + '\n\n'+ |
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295 | ('=').repeat(54)+'\n\n'+ |
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296 | 'Response Header: \n'+ |
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297 | ('-').repeat(100)+ '\n'+ |
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298 | _responseHeader + '\n'+ |
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299 | 'Response Body: \n'+ |
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300 | ('-').repeat(100)+ '\n'+ |
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301 | _responseBody ); |
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302 | } |
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303 | } |
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304 | |
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305 | |
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306 | /** |
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307 | * |
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308 | * |
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309 | * @access private |
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310 | */ |
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311 | function _getJsonDecodedResponse( response ) |
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312 | { |
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313 | if( _this.onStateChange ) |
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314 | { |
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315 | _this.onStateChange( 5, |
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316 | ((_this.statusTranslation) ? _this.statusTranslation[5] : 5), |
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317 | _this.onStateChangeId ); |
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318 | } |
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319 | return JSON.parse(response); |
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320 | } |
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321 | |
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322 | |
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323 | function _clearVirtualRequestData() |
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324 | { |
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325 | _virtualRequest = new Object(); |
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326 | } |
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327 | |
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328 | /** |
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329 | * debugging, triggers AJAX requests / responses into div container |
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330 | * |
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331 | * @access private |
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332 | */ |
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333 | function _triggerAjaxData( data ) |
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334 | { |
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335 | if( $('id_AJAX_data') ) |
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336 | { |
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337 | $('id_AJAX_data').innerHTML = data + $('id_AJAX_data').innerHTML; |
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338 | } |
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339 | } |
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340 | } |
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