Complex classes like ErrorHandler often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use ErrorHandler, and based on these observations, apply Extract Interface, too.
1 | <?php |
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31 | class ErrorHandler extends \yii\base\ErrorHandler |
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32 | { |
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33 | /** |
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34 | * @var int maximum number of source code lines to be displayed. Defaults to 19. |
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35 | */ |
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36 | public $maxSourceLines = 19; |
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37 | /** |
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38 | * @var int maximum number of trace source code lines to be displayed. Defaults to 13. |
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39 | */ |
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40 | public $maxTraceSourceLines = 13; |
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41 | /** |
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42 | * @var string the route (e.g. `site/error`) to the controller action that will be used |
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43 | * to display external errors. Inside the action, it can retrieve the error information |
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44 | * using `Yii::$app->errorHandler->exception`. This property defaults to null, meaning ErrorHandler |
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45 | * will handle the error display. |
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46 | */ |
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47 | public $errorAction; |
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48 | /** |
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49 | * @var string the path of the view file for rendering exceptions without call stack information. |
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50 | */ |
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51 | public $errorView = '@yii/views/errorHandler/error.php'; |
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52 | /** |
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53 | * @var string the path of the view file for rendering exceptions. |
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54 | */ |
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55 | public $exceptionView = '@yii/views/errorHandler/exception.php'; |
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56 | /** |
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57 | * @var string the path of the view file for rendering exceptions and errors call stack element. |
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58 | */ |
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59 | public $callStackItemView = '@yii/views/errorHandler/callStackItem.php'; |
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60 | /** |
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61 | * @var string the path of the view file for rendering previous exceptions. |
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62 | */ |
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63 | public $previousExceptionView = '@yii/views/errorHandler/previousException.php'; |
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64 | /** |
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65 | * @var array list of the PHP predefined variables that should be displayed on the error page. |
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66 | * Note that a variable must be accessible via `$GLOBALS`. Otherwise it won't be displayed. |
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67 | * Defaults to `['_GET', '_POST', '_FILES', '_COOKIE', '_SESSION']`. |
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68 | * @see renderRequest() |
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69 | * @since 2.0.7 |
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70 | */ |
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71 | public $displayVars = ['_GET', '_POST', '_FILES', '_COOKIE', '_SESSION']; |
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72 | |||
73 | |||
74 | /** |
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75 | * Renders the exception. |
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76 | * @param \Exception|\Error $exception the exception to be rendered. |
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77 | */ |
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78 | 1 | protected function renderException($exception) |
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79 | { |
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80 | 1 | if (Yii::$app->has('response')) { |
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81 | 1 | $response = Yii::$app->getResponse(); |
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82 | // reset parameters of response to avoid interference with partially created response data |
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83 | // in case the error occurred while sending the response. |
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84 | 1 | $response->isSent = false; |
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85 | 1 | $response->stream = null; |
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86 | 1 | $response->data = null; |
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87 | 1 | $response->content = null; |
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88 | } else { |
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89 | $response = new Response(); |
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90 | } |
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91 | |||
92 | 1 | $response->setStatusCodeByException($exception); |
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93 | |||
94 | 1 | $useErrorView = $response->format === Response::FORMAT_HTML && (!YII_DEBUG || $exception instanceof UserException); |
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95 | |||
96 | 1 | if ($useErrorView && $this->errorAction !== null) { |
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97 | $result = Yii::$app->runAction($this->errorAction); |
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98 | if ($result instanceof Response) { |
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99 | $response = $result; |
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100 | } else { |
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101 | $response->data = $result; |
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102 | } |
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103 | 1 | } elseif ($response->format === Response::FORMAT_HTML) { |
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104 | 1 | if ($this->shouldRenderSimpleHtml()) { |
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105 | // AJAX request |
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106 | $response->data = '<pre>' . $this->htmlEncode(static::convertExceptionToString($exception)) . '</pre>'; |
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107 | } else { |
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108 | // if there is an error during error rendering it's useful to |
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109 | // display PHP error in debug mode instead of a blank screen |
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110 | 1 | if (YII_DEBUG) { |
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111 | 1 | ini_set('display_errors', 1); |
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112 | } |
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113 | 1 | $file = $useErrorView ? $this->errorView : $this->exceptionView; |
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114 | 1 | $response->data = $this->renderFile($file, [ |
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115 | 1 | 'exception' => $exception, |
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116 | ]); |
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117 | } |
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118 | } elseif ($response->format === Response::FORMAT_RAW) { |
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119 | $response->data = static::convertExceptionToString($exception); |
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120 | } else { |
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121 | $response->data = $this->convertExceptionToArray($exception); |
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122 | } |
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123 | |||
124 | 1 | $response->send(); |
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125 | 1 | } |
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126 | |||
127 | /** |
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128 | * Converts an exception into an array. |
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129 | * @param \Exception|\Error $exception the exception being converted |
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130 | * @return array the array representation of the exception. |
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131 | */ |
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132 | protected function convertExceptionToArray($exception) |
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133 | { |
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134 | if (!YII_DEBUG && !$exception instanceof UserException && !$exception instanceof HttpException) { |
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135 | $exception = new HttpException(500, Yii::t('yii', 'An internal server error occurred.')); |
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136 | } |
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137 | |||
138 | $array = [ |
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139 | 'name' => ($exception instanceof Exception || $exception instanceof ErrorException) ? $exception->getName() : 'Exception', |
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140 | 'message' => $exception->getMessage(), |
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141 | 'code' => $exception->getCode(), |
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142 | ]; |
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143 | if ($exception instanceof HttpException) { |
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144 | $array['status'] = $exception->statusCode; |
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145 | } |
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146 | if (YII_DEBUG) { |
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147 | $array['type'] = get_class($exception); |
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148 | if (!$exception instanceof UserException) { |
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149 | $array['file'] = $exception->getFile(); |
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150 | $array['line'] = $exception->getLine(); |
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151 | $array['stack-trace'] = explode("\n", $exception->getTraceAsString()); |
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152 | if ($exception instanceof \yii\db\Exception) { |
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153 | $array['error-info'] = $exception->errorInfo; |
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154 | } |
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155 | } |
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156 | } |
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157 | if (($prev = $exception->getPrevious()) !== null) { |
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158 | $array['previous'] = $this->convertExceptionToArray($prev); |
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159 | } |
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160 | |||
161 | return $array; |
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162 | } |
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163 | |||
164 | /** |
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165 | * Converts special characters to HTML entities. |
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166 | * @param string $text to encode. |
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167 | * @return string encoded original text. |
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168 | */ |
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169 | 3 | public function htmlEncode($text) |
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173 | |||
174 | /** |
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175 | * Adds informational links to the given PHP type/class. |
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176 | * @param string $code type/class name to be linkified. |
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177 | * @return string linkified with HTML type/class name. |
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178 | */ |
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179 | public function addTypeLinks($code) |
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214 | |||
215 | /** |
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216 | * Returns the informational link URL for a given PHP type/class. |
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217 | * @param string $class the type or class name. |
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218 | * @param string|null $method the method name. |
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219 | * @return string|null the informational link URL. |
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220 | * @see addTypeLinks() |
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221 | */ |
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222 | protected function getTypeUrl($class, $method) |
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236 | |||
237 | /** |
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238 | * Renders a view file as a PHP script. |
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239 | * @param string $_file_ the view file. |
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240 | * @param array $_params_ the parameters (name-value pairs) that will be extracted and made available in the view file. |
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241 | * @return string the rendering result |
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242 | */ |
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243 | 4 | public function renderFile($_file_, $_params_) |
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257 | |||
258 | /** |
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259 | * Renders the previous exception stack for a given Exception. |
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260 | * @param \Exception $exception the exception whose precursors should be rendered. |
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261 | * @return string HTML content of the rendered previous exceptions. |
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262 | * Empty string if there are none. |
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263 | */ |
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264 | public function renderPreviousExceptions($exception) |
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272 | |||
273 | /** |
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274 | * Renders a single call stack element. |
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275 | * @param string|null $file name where call has happened. |
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276 | * @param int|null $line number on which call has happened. |
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277 | * @param string|null $class called class name. |
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278 | * @param string|null $method called function/method name. |
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279 | * @param array $args array of method arguments. |
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280 | * @param int $index number of the call stack element. |
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281 | * @return string HTML content of the rendered call stack element. |
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282 | */ |
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283 | public function renderCallStackItem($file, $line, $class, $method, $args, $index) |
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311 | |||
312 | /** |
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313 | * Renders call stack. |
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314 | * @param \Exception|\ParseError $exception exception to get call stack from |
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315 | * @return string HTML content of the rendered call stack. |
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316 | * @since 2.0.12 |
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317 | */ |
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318 | public function renderCallStack($exception) |
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336 | |||
337 | /** |
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338 | * Renders the global variables of the request. |
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339 | * List of global variables is defined in [[displayVars]]. |
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340 | * @return string the rendering result |
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341 | * @see displayVars |
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342 | */ |
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343 | public function renderRequest() |
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354 | |||
355 | /** |
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356 | * Determines whether given name of the file belongs to the framework. |
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357 | * @param string $file name to be checked. |
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358 | * @return bool whether given name of the file belongs to the framework. |
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359 | */ |
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360 | public function isCoreFile($file) |
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364 | |||
365 | /** |
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366 | * Creates HTML containing link to the page with the information on given HTTP status code. |
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367 | * @param int $statusCode to be used to generate information link. |
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368 | * @param string $statusDescription Description to display after the the status code. |
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369 | * @return string generated HTML with HTTP status code information. |
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370 | */ |
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371 | public function createHttpStatusLink($statusCode, $statusDescription) |
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375 | |||
376 | /** |
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377 | * Creates string containing HTML link which refers to the home page of determined web-server software |
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378 | * and its full name. |
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379 | * @return string server software information hyperlink. |
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380 | */ |
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381 | public function createServerInformationLink() |
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403 | |||
404 | /** |
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405 | * Creates string containing HTML link which refers to the page with the current version |
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406 | * of the framework and version number text. |
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407 | * @return string framework version information hyperlink. |
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408 | */ |
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409 | public function createFrameworkVersionLink() |
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413 | |||
414 | /** |
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415 | * Converts arguments array to its string representation |
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416 | * |
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417 | * @param array $args arguments array to be converted |
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418 | * @return string string representation of the arguments array |
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419 | */ |
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420 | public function argumentsToString($args) |
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467 | |||
468 | /** |
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469 | * Returns human-readable exception name |
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470 | * @param \Exception $exception |
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471 | * @return string human-readable exception name or null if it cannot be determined |
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472 | */ |
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473 | 3 | public function getExceptionName($exception) |
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480 | |||
481 | /** |
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482 | * @return bool if simple HTML should be rendered |
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483 | * @since 2.0.12 |
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484 | */ |
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485 | protected function shouldRenderSimpleHtml() |
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489 | } |
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490 |
In PHP, under loose comparison (like
==
, or!=
, orswitch
conditions), values of different types might be equal.For
string
values, the empty string''
is a special case, in particular the following results might be unexpected: