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 Link 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 Link, and based on these observations, apply Extract Interface, too.
1 | <?php |
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40 | class Link |
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41 | { |
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42 | /** |
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43 | * class constants. |
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44 | */ |
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45 | const LINK_AMPERSAND = '&'; |
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46 | const LINK_CATEGORY = 'category/'; |
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47 | const LINK_CONTENT = 'content/'; |
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48 | const LINK_EQUAL = '='; |
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49 | const LINK_FRAGMENT_SEPARATOR = '#'; |
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50 | const LINK_HTML_MINUS = '-'; |
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51 | const LINK_HTML_UNDERSCORE = '_'; |
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52 | const LINK_HTML_SLASH = '/'; |
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53 | const LINK_HTML_TARGET_BLANK = '_blank'; |
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54 | const LINK_HTML_TARGET_PARENT = '_parent'; |
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55 | const LINK_HTML_TARGET_SELF = '_self'; |
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56 | const LINK_HTML_TARGET_TOP = '_top'; |
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57 | const LINK_NEWS = 'news/'; |
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58 | const LINK_SITEMAP = 'sitemap/'; |
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59 | const LINK_SLASH = '/'; |
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60 | const LINK_SEARCHPART_SEPARATOR = '?'; |
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61 | const LINK_TAGS = 'tags/'; |
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62 | |||
63 | const LINK_INDEX_ADMIN = '/admin/index.php'; |
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64 | const LINK_INDEX_HOME = '/index.php'; |
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65 | |||
66 | const LINK_GET_ACTION = 'action'; |
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67 | const LINK_GET_ARTLANG = 'artlang'; |
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68 | const LINK_GET_CATEGORY = 'cat'; |
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69 | const LINK_GET_HIGHLIGHT = 'highlight'; |
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70 | const LINK_GET_ID = 'id'; |
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71 | const LINK_GET_LANG = 'lang'; |
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72 | const LINK_GET_LETTER = 'letter'; |
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73 | const LINK_GET_NEWS_ID = 'newsid'; |
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74 | const LINK_GET_NEWS_LANG = 'newslang'; |
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75 | const LINK_GET_PAGE = 'seite'; |
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76 | const LINK_GET_SIDS = 'sid'; |
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77 | const LINK_GET_TAGGING_ID = 'tagging_id'; |
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78 | const LINK_GET_LANGS = 'langs'; |
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79 | |||
80 | const LINK_GET_ACTION_ADD = 'add'; |
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81 | const LINK_GET_ACTION_FAQ = 'faq'; |
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82 | const LINK_GET_ACTION_ASK = 'ask'; |
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83 | const LINK_GET_ACTION_CONTACT = 'contact'; |
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84 | const LINK_GET_ACTION_GLOSSARY = 'glossary'; |
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85 | const LINK_GET_ACTION_HELP = 'help'; |
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86 | const LINK_GET_ACTION_LOGIN = 'login'; |
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87 | const LINK_GET_ACTION_NEWS = 'news'; |
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88 | const LINK_GET_ACTION_OPEN = 'open'; |
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89 | const LINK_GET_ACTION_PASSWORD = 'password'; |
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90 | const LINK_GET_ACTION_REGISTER = 'register'; |
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91 | const LINK_GET_ACTION_SEARCH = 'search'; |
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92 | const LINK_GET_ACTION_SITEMAP = 'sitemap'; |
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93 | const LINK_GET_ACTION_SHOW = 'show'; |
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94 | |||
95 | const LINK_HTML_CATEGORY = 'category'; |
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96 | const LINK_HTML_EXTENSION = '.html'; |
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97 | const LINK_HTML_SITEMAP = 'sitemap'; |
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98 | |||
99 | const LINK_HTML_ADDCONTENT = 'addcontent.html'; |
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100 | const LINK_HTML_ASK = 'ask.html'; |
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101 | const LINK_HTML_CONTACT = 'contact.html'; |
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102 | const LINK_HTML_GLOSSARY = 'glossary.html'; |
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103 | const LINK_HTML_HELP = 'help.html'; |
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104 | const LINK_HTML_LOGIN = 'login.html'; |
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105 | const LINK_HTML_OPEN = 'open.html'; |
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106 | const LINK_HTML_PASSWORD = 'password.html'; |
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107 | const LINK_HTML_REGISTER = 'register.html'; |
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108 | const LINK_HTML_SEARCH = 'search.html'; |
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109 | const LINK_HTML_SHOWCAT = 'showcat.html'; |
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110 | |||
111 | /** |
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112 | * URL. |
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113 | * |
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114 | * @var string |
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115 | */ |
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116 | public $url = ''; |
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117 | |||
118 | /** |
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119 | * CSS class. |
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120 | * |
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121 | * @var string |
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122 | */ |
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123 | public $class = ''; |
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124 | |||
125 | /** |
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126 | * Linktext. |
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127 | * |
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128 | * @var string |
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129 | */ |
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130 | public $text = ''; |
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131 | |||
132 | /** |
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133 | * Tooltip. |
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134 | * |
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135 | * @var string |
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136 | */ |
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137 | public $tooltip = ''; |
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138 | |||
139 | /** |
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140 | * Target. |
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141 | * |
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142 | * @var string |
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143 | */ |
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144 | public $target = ''; |
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145 | |||
146 | /** |
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147 | * Name selector. |
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148 | * |
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149 | * @var string |
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150 | */ |
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151 | public $name = ''; |
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152 | |||
153 | /** |
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154 | * property specific to the SEO/SEF URLs. |
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155 | * |
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156 | * @var string |
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157 | */ |
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158 | public $itemTitle = ''; |
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159 | |||
160 | /** |
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161 | * Item property for HTML5 microdata. |
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162 | * |
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163 | * @var string |
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164 | */ |
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165 | protected $itemprop = ''; |
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166 | |||
167 | /** |
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168 | * rel property. |
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169 | * |
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170 | * @var string |
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171 | */ |
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172 | protected $rel = ''; |
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173 | |||
174 | /** |
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175 | * id selector. |
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176 | * |
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177 | * @var string |
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178 | */ |
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179 | public $id = ''; |
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180 | |||
181 | /** |
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182 | * @var Configuration |
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183 | */ |
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184 | private $config = null; |
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185 | |||
186 | /** |
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187 | * Constructor. |
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188 | * |
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189 | * @param string $url URL |
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190 | * @param Configuration $config |
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191 | */ |
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192 | public function __construct($url, Configuration $config) |
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197 | |||
198 | /** |
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199 | * Checks if webserver is an IIS Server. |
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200 | * |
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201 | * @return bool |
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202 | */ |
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203 | public static function isIISServer() |
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207 | |||
208 | /** |
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209 | * Checks if the the current URL is the main index.php file. |
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210 | * |
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211 | * @return bool |
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212 | */ |
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213 | protected function isHomeIndex() |
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221 | |||
222 | /** |
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223 | * Checks if URL is an internal reference. |
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224 | * |
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225 | * @return bool |
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226 | */ |
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227 | protected function isInternalReference() |
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238 | |||
239 | /** |
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240 | * Checks if URL is a relative system link. |
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241 | * |
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242 | * @return bool |
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243 | */ |
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244 | protected function isRelativeSystemLink() |
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253 | |||
254 | /** |
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255 | * Checks if URL is a system link. |
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256 | * |
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257 | * @return bool |
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258 | */ |
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259 | protected function isSystemLink() |
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269 | |||
270 | /** |
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271 | * @param string $itemprop Item property |
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272 | */ |
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273 | public function setItemProperty($itemprop) |
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277 | |||
278 | /** |
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279 | * @param string $rel rel property |
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280 | */ |
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281 | public function setRelation($rel) |
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285 | |||
286 | /** |
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287 | * Checks if URL contains a scheme. |
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288 | * |
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289 | * @return bool |
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290 | */ |
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291 | protected function hasScheme() |
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297 | |||
298 | /** |
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299 | * Returns a search engine optimized title. |
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300 | * |
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301 | * @param string $title |
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302 | * |
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303 | * @return string |
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304 | */ |
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305 | public function getSEOItemTitle($title = '') |
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344 | |||
345 | /** |
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346 | * Returns the HTTP GET parameters. |
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347 | * @return string |
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348 | */ |
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349 | protected function getHttpGetParameters(): array |
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375 | |||
376 | /** |
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377 | * Returns the query of an URL. |
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378 | * @return array |
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379 | */ |
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380 | protected function getQuery(): array |
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397 | |||
398 | /** |
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399 | * Returns the default scheme. |
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400 | * @return string |
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401 | */ |
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402 | protected function getDefaultScheme(): string |
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411 | |||
412 | /** |
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413 | * Returns the system scheme, http or https. |
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414 | * @return string |
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415 | */ |
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416 | public function getSystemScheme(): string |
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438 | |||
439 | /** |
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440 | * Returns the relative URI. |
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441 | * @param string $path |
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442 | * @return string |
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443 | */ |
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444 | public static function getSystemRelativeUri(string $path = null): string |
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452 | |||
453 | /** |
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454 | * Returns the system URI. |
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455 | * |
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456 | * $_SERVER['HTTP_HOST'] is the name of the website or virtual host name (HTTP/1.1) |
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457 | * Precisely, it contains what the user has written in the Host request-header, see below. |
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458 | * RFC 2616: The Host request-header field specifies the Internet host and port number of the resource |
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459 | * being requested, as obtained from the original URI given by the user or referring resource |
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460 | * |
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461 | * @param string $path |
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462 | * @return string |
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463 | */ |
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464 | public function getSystemUri($path = null): string |
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473 | |||
474 | /** |
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475 | * Builds a HTML anchor. |
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476 | * @return string |
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477 | */ |
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478 | public function toHtmlAnchor():string |
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523 | |||
524 | /** |
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525 | * Appends the session id. |
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526 | * @param string $url URL |
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527 | * @param int $sids Session Id |
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528 | * @return string |
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529 | */ |
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530 | protected function appendSids(string $url, int $sids): string |
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540 | |||
541 | /** |
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542 | * Rewrites a URL string. Checks mod_rewrite support and 'rewrite' |
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543 | * the passed (system) uri according to the rewrite rules written |
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544 | * in .htaccess |
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545 | * @param bool $removeSessionFromUrl Remove session from URL |
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546 | * @return string |
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547 | */ |
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548 | public function toString(bool $removeSessionFromUrl = false): string |
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708 | |||
709 | /** |
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710 | * Transforms a URI. |
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711 | * @return string |
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712 | */ |
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713 | public function toUri(): string |
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724 | |||
725 | /** |
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726 | * Returns the current URL. |
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727 | * @return string |
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728 | */ |
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729 | public function getCurrentUrl(): string |
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733 | |||
734 | /** |
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735 | * Static method to generate simple HTML anchors. |
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736 | * @static |
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737 | * @param string $url URL |
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738 | * @param string $text Text |
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739 | * @param bool $active Add CSS class named "active"? |
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740 | * @return string |
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741 | */ |
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742 | public static function renderNavigationLink(string $url, string $text, bool $active = false): string |
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751 | } |
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752 |