Complex classes like Upload 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 Upload, and based on these observations, apply Extract Interface, too.
1 | <?php |
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14 | trait Upload { |
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15 | |||
16 | /** |
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17 | *@var string contains the name of the file to be uploaded. |
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18 | */ |
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19 | protected $FileName; |
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20 | /** |
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21 | *@var string contains the temporary name of the file to be uploaded. |
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22 | */ |
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23 | protected $TempFileName; |
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24 | /** |
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25 | *@var string contains directory where the files should be uploaded. |
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26 | */ |
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27 | protected $UploadDirectory; |
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28 | /** |
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29 | *@var string contains an array of valid extensions which are allowed to be uploaded. |
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30 | */ |
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31 | protected $ValidExtensions; |
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32 | /** |
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33 | *@var string contains a message which can be used for debugging. |
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34 | */ |
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35 | protected $Message; |
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36 | /** |
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37 | *@var integer contains maximum size of fiels to be uploaded in bytes. |
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38 | */ |
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39 | protected $MaximumFileSize; |
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40 | /** |
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41 | *@var bool contains whether or not the files being uploaded are images. |
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42 | */ |
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43 | protected $IsImage; |
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44 | /** |
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45 | *@var string contains the email address of the recipient of upload logs. |
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46 | */ |
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47 | protected $Email; |
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48 | /** |
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49 | *@var integer contains maximum width of images to be uploaded. |
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50 | */ |
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51 | protected $MaximumWidth; |
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52 | /** |
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53 | *@var integer contains maximum height of images to be uploaded. |
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54 | */ |
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55 | protected $MaximumHeight; |
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56 | |||
57 | public function upload() |
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61 | |||
62 | /** |
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63 | *@method bool ValidateExtension() returns whether the extension of file to be uploaded |
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64 | * is allowable or not. |
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65 | *@return true the extension is valid. |
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66 | *@return false the extension is invalid. |
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67 | */ |
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68 | public function ValidateExtension() |
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95 | |||
96 | /** |
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97 | *@method bool ValidateSize() returns whether the file size is acceptable. |
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98 | *@return true the size is smaller than the alloted value. |
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99 | *@return false the size is larger than the alloted value. |
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100 | */ |
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101 | public function ValidateSize() |
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120 | |||
121 | /** |
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122 | *@method bool ValidateExistance() determins whether the file already exists. If so, rename $FileName. |
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123 | *@return true can never be returned as all file names must be unique. |
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124 | *@return false the file name does not exist. |
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125 | */ |
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126 | public function ValidateExistance() |
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142 | |||
143 | /** |
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144 | *@method bool ValidateDirectory() |
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145 | *@return true the UploadDirectory exists, writable, and has a traling slash. |
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146 | *@return false the directory was never set, does not exist, or is not writable. |
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147 | */ |
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148 | public function ValidateDirectory() |
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177 | |||
178 | /** |
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179 | *@method bool ValidateImage() |
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180 | *@return true the image is smaller than the alloted dimensions. |
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181 | *@return false the width and/or height is larger then the alloted dimensions. |
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182 | */ |
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183 | public function ValidateImage() { |
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206 | |||
207 | /** |
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208 | *@method bool UploadFile() uploads the file to the server after passing all the validations. |
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209 | *@return true the file was uploaded. |
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210 | *@return false the upload failed. |
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211 | */ |
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212 | public function uploadFile() |
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251 | |||
252 | #Accessors and Mutators beyond this point. |
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253 | #Siginificant documentation is not needed. |
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254 | public function SetFileName($argv) |
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258 | |||
259 | public function SetUploadDirectory($argv) |
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263 | |||
264 | public function SetTempName($argv) |
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268 | |||
269 | public function SetValidExtensions($argv) |
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273 | |||
274 | public function SetMessage($argv) |
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278 | |||
279 | public function SetMaximumFileSize($argv) |
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283 | |||
284 | public function SetEmail($argv) |
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288 | |||
289 | public function SetIsImage($argv) |
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293 | |||
294 | public function SetMaximumWidth($argv) |
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298 | |||
299 | public function SetMaximumHeight($argv) |
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307 | |||
308 | public function GetUploadDirectory() |
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312 | |||
313 | public function GetTempName() |
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317 | |||
318 | public function GetValidExtensions() |
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322 | |||
323 | public function GetMessage() |
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331 | |||
332 | public function GetMaximumFileSize() |
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336 | |||
337 | public function GetEmail() |
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341 | |||
342 | public function GetIsImage() |
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346 | |||
347 | public function GetMaximumWidth() |
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351 | |||
352 | public function GetMaximumHeight() |
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356 | } |
If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: