Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Nexcessnet_Turpentine_Helper_Esi 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 Nexcessnet_Turpentine_Helper_Esi, and based on these observations, apply Extract Interface, too.
1 | <?php |
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22 | class Nexcessnet_Turpentine_Helper_Esi extends Mage_Core_Helper_Abstract { |
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23 | const ESI_DATA_PARAM = 'data'; |
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24 | const ESI_TTL_PARAM = 'ttl'; |
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25 | const ESI_CACHE_TYPE_PARAM = 'access'; |
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26 | const ESI_SCOPE_PARAM = 'scope'; |
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27 | const ESI_METHOD_PARAM = 'method'; |
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28 | const ESI_HMAC_PARAM = 'hmac'; |
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29 | const MAGE_CACHE_NAME = 'turpentine_esi_blocks'; |
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30 | |||
31 | /** |
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32 | * Cache for layout XML |
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33 | * |
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34 | * @var Mage_Core_Model_Layout_Element|SimpleXMLElement |
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35 | */ |
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36 | protected $_layoutXml = null; |
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37 | |||
38 | /** |
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39 | * Get whether ESI includes are enabled or not |
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40 | * |
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41 | * @return bool |
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42 | */ |
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43 | public function getEsiEnabled() { |
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46 | |||
47 | /** |
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48 | * Get if ESI should be used for this request |
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49 | * |
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50 | * @return bool |
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51 | */ |
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52 | public function shouldResponseUseEsi() { |
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56 | |||
57 | /** |
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58 | * Check if ESI includes are enabled and throw an exception if not |
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59 | * |
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60 | * @return null |
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61 | */ |
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62 | public function ensureEsiEnabled() { |
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67 | |||
68 | /** |
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69 | * Get the name of the URL param that holds the ESI block hash |
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70 | * |
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71 | * @return string |
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72 | */ |
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73 | public function getEsiDataParam() { |
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76 | |||
77 | /** |
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78 | * Get the URL param name for the ESI block cache type |
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79 | * |
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80 | * @return string |
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81 | */ |
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82 | public function getEsiCacheTypeParam() { |
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85 | |||
86 | /** |
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87 | * Get the URL param name for the ESI block scope |
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88 | * |
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89 | * @return string |
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90 | */ |
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91 | public function getEsiScopeParam() { |
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94 | |||
95 | /** |
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96 | * Get the URL param name for the ESI block TTL |
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97 | * |
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98 | * @return string |
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99 | */ |
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100 | public function getEsiTtlParam() { |
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103 | |||
104 | /** |
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105 | * Get the URL param name for the ESI inclusion method |
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106 | * |
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107 | * @return string |
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108 | */ |
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109 | public function getEsiMethodParam() { |
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112 | |||
113 | /** |
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114 | * Get the URL param name for the ESI HMAC |
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115 | * |
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116 | * @return string |
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117 | */ |
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118 | public function getEsiHmacParam() { |
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121 | |||
122 | /** |
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123 | * Get referrer param |
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124 | * |
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125 | * @return string |
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126 | */ |
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127 | public function getEsiReferrerParam() { |
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130 | |||
131 | /** |
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132 | * Get whether ESI debugging is enabled or not |
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133 | * |
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134 | * @return bool |
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135 | */ |
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136 | public function getEsiDebugEnabled() { |
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140 | |||
141 | /** |
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142 | * Get whether block name logging is enabled or not |
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143 | * |
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144 | * @return bool |
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145 | */ |
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146 | public function getEsiBlockLogEnabled() { |
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150 | |||
151 | /** |
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152 | * Check if the flash messages are enabled and we're not in the admin section |
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153 | * |
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154 | * @return bool |
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155 | */ |
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156 | public function shouldFixFlashMessages() { |
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160 | |||
161 | /** |
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162 | * Get URL for redirects and dummy requests |
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163 | * |
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164 | * @return string |
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165 | */ |
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166 | public function getDummyUrl() { |
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169 | |||
170 | /** |
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171 | * Get mock request |
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172 | * |
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173 | * Used to pretend that the request was for the base URL instead of |
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174 | * turpentine/esi/getBlock while rendering ESI blocks. Not perfect, but may |
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175 | * be good enough |
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176 | * |
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177 | * @return Mage_Core_Controller_Request_Http |
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178 | */ |
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179 | public function getDummyRequest($url = null) { |
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187 | |||
188 | /** |
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189 | * Get the cache type Magento uses |
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190 | * |
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191 | * @return string |
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192 | */ |
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193 | public function getMageCacheName() { |
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196 | |||
197 | /** |
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198 | * Get the list of cache clear events to include with every ESI block |
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199 | * |
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200 | * @return string[] |
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201 | */ |
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202 | public function getDefaultCacheClearEvents() { |
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209 | |||
210 | /** |
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211 | * Get the list of events that should cause the ESI cache to be cleared |
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212 | * |
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213 | * @return string[] |
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214 | */ |
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215 | public function getCacheClearEvents() { |
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227 | |||
228 | /** |
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229 | * Get the default private ESI block TTL |
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230 | * |
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231 | * @return string |
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232 | */ |
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233 | public function getDefaultEsiTtl() { |
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240 | |||
241 | /** |
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242 | * Get the CORS origin field from the unsecure base URL |
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243 | * |
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244 | * If this isn't added to AJAX responses they won't load properly |
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245 | * |
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246 | * @return string |
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247 | */ |
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248 | public function getCorsOrigin($url = null) { |
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261 | |||
262 | /** |
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263 | * Get the layout's XML structure |
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264 | * |
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265 | * This is cached because it's expensive to load for each ESI'd block |
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266 | * |
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267 | * @return Mage_Core_Model_Layout_Element|SimpleXMLElement |
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268 | */ |
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269 | public function getLayoutXml() { |
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289 | |||
290 | /** |
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291 | * Get the cache key for the cache clear events |
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292 | * |
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293 | * @return string |
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294 | */ |
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295 | View Code Duplication | public function getCacheClearEventsCacheKey() { |
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306 | |||
307 | /** |
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308 | * Get the cache key for the file layouts xml |
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309 | * |
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310 | * @return string |
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311 | */ |
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312 | View Code Duplication | public function getFileLayoutUpdatesXmlCacheKey() { |
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323 | |||
324 | /** |
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325 | * Generate an ESI tag to be replaced by the content from the given URL |
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326 | * |
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327 | * Generated tag looks like: |
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328 | * <esi:include src="$url" /> |
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329 | * |
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330 | * @param string $url url to pull content from |
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331 | * @return string |
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332 | */ |
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333 | public function buildEsiIncludeFragment($url) { |
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336 | |||
337 | /** |
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338 | * Generate an ESI tag with content that is removed when ESI processed, and |
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339 | * visible when not |
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340 | * |
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341 | * Generated tag looks like: |
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342 | * <esi:remove>$content</esi> |
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343 | * |
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344 | * @param string $content content to be removed |
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345 | * @return string |
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346 | */ |
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347 | public function buildEsiRemoveFragment($content) { |
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350 | |||
351 | /** |
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352 | * Get URL for grabbing form key via ESI |
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353 | * |
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354 | * @return string |
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355 | */ |
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356 | public function getFormKeyEsiUrl() { |
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368 | |||
369 | /** |
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370 | * Grab a block node by name from the layout XML. |
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371 | * |
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372 | * Multiple blocks with the same name may exist in the layout, because some themes |
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373 | * use 'unsetChild' to remove a block and create it with the same name somewhere |
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374 | * else. For example Ultimo does this. |
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375 | * |
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376 | * @param Mage_Core_Model_Layout $layout |
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377 | * @param string $blockName value of name= attribute in layout XML |
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378 | * @return Mage_Core_Model_Layout_Element |
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379 | */ |
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380 | public function getEsiLayoutBlockNode($layout, $blockName) { |
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396 | |||
397 | /** |
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398 | * Load the ESI cache clear events from the layout |
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399 | * |
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400 | * @return array |
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401 | */ |
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402 | protected function _loadEsiCacheClearEvents() { |
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418 | |||
419 | /** |
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420 | * Load the layout's XML structure, bypassing any caching |
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421 | * |
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422 | * @return Mage_Core_Model_Layout_Element |
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423 | */ |
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424 | protected function _loadLayoutXml() { |
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437 | } |
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438 |
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: