Complex classes like Container 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 Container, and based on these observations, apply Extract Interface, too.
1 | <?php |
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15 | class Container implements ContainerInterface { |
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16 | private $currentRule; |
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17 | private $currentRuleName; |
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18 | private $instances; |
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19 | private $rules; |
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20 | private $factories; |
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21 | |||
22 | /** |
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23 | * Construct a new instance of the {@link Container} class. |
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24 | */ |
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25 | 67 | public function __construct() { |
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26 | 67 | $this->rules = ['*' => ['inherit' => true, 'constructorArgs' => null]]; |
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27 | 67 | $this->instances = []; |
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28 | 67 | $this->factories = []; |
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29 | |||
30 | $this->rule('*'); |
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31 | 67 | } |
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32 | |||
33 | /** |
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34 | * Normalize a container entry ID. |
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35 | * |
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36 | * @param string $id The ID to normalize. |
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37 | * @return string Returns a normalized ID as a string. |
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38 | */ |
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39 | private function normalizeID($id) { |
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40 | return ltrim($id, '\\'); |
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41 | } |
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42 | |||
43 | /** |
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44 | * Set the current rule to the default rule. |
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45 | * |
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46 | * @return $this |
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47 | */ |
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48 | public function defaultRule() { |
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49 | return $this->rule('*'); |
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50 | } |
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51 | |||
52 | /** |
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53 | * Set the current rule. |
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54 | * |
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55 | * @param string $id The ID of the rule. |
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56 | * @return $this |
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57 | */ |
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58 | 36 | public function rule($id) { |
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59 | $id = $this->normalizeID($id); |
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60 | |||
61 | 36 | if (!isset($this->rules[$id])) { |
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62 | 26 | $this->rules[$id] = []; |
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63 | } |
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64 | 36 | $this->currentRuleName = $id; |
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65 | 36 | $this->currentRule = &$this->rules[$id]; |
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66 | |||
67 | 36 | return $this; |
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68 | } |
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69 | |||
70 | /** |
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71 | * Get the class name of the current rule. |
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72 | * |
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73 | * @return string Returns a class name. |
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74 | */ |
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75 | 2 | public function getClass() { |
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78 | |||
79 | /** |
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80 | * Set the name of the class for the current rule. |
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81 | * |
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82 | * @param string $className A valid class name. |
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83 | * @return $this |
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84 | */ |
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85 | 5 | public function setClass($className) { |
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89 | |||
90 | /** |
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91 | * Get the rule that the current rule references. |
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92 | * |
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93 | * @return string Returns a reference name or an empty string if there is no reference. |
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94 | */ |
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95 | 3 | public function getAliasOf() { |
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98 | |||
99 | /** |
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100 | * Set the rule that the current rule is an alias of. |
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101 | * |
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102 | * @param string $alias The name of an entry in the container to point to. |
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103 | * @return $this |
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104 | */ |
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105 | 4 | public function setAliasOf($alias) { |
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106 | $alias = $this->normalizeID($alias); |
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107 | |||
108 | 4 | if ($alias === $this->currentRuleName) { |
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109 | trigger_error("You cannot set alias '$alias' to itself.", E_USER_NOTICE); |
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110 | } else { |
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111 | 3 | $this->currentRule['aliasOf'] = $alias; |
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112 | 1 | } |
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113 | 4 | return $this; |
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114 | } |
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115 | |||
116 | /** |
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117 | * Add an alias of the current rule. |
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118 | * |
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119 | * Setting an alias to the current rule means that getting an item with the alias' name will be like getting the item |
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120 | * with the current rule. If the current rule is shared then the same shared instance will be returned. |
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121 | * |
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122 | * If {@link Container::addAlias()} is called with an alias that is the same as the current rule then an **E_USER_NOTICE** |
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123 | * level error is raised and the alias is not added. |
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124 | * |
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125 | * @param string $alias The alias to set. |
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126 | * @return $this |
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127 | */ |
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128 | 6 | public function addAlias($alias) { |
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129 | $alias = $this->normalizeID($alias); |
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130 | |||
131 | 6 | if ($alias === $this->currentRuleName) { |
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132 | trigger_error("Tried to set alias '$alias' to self.", E_USER_NOTICE); |
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133 | } else { |
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134 | 5 | $this->rules[$alias]['aliasOf'] = $this->currentRuleName; |
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135 | 1 | } |
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136 | 6 | return $this; |
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137 | } |
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138 | |||
139 | /** |
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140 | * Remove an alias of the current rule. |
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141 | * |
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142 | * If {@link Container::removeAlias()} is called with an alias that references a different rule then an **E_USER_NOTICE** |
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143 | * level error is raised, but the alias is still removed. |
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144 | * |
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145 | * @param string $alias The alias to remove. |
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146 | * @return $this |
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147 | */ |
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148 | 2 | public function removeAlias($alias) { |
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149 | $alias = $this->normalizeID($alias); |
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150 | |||
151 | 2 | if (!empty($this->rules[$alias]['aliasOf']) && $this->rules[$alias]['aliasOf'] !== $this->currentRuleName) { |
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152 | trigger_error("Alias '$alias' does not point to the current rule.", E_USER_NOTICE); |
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153 | } |
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154 | |||
155 | 2 | unset($this->rules[$alias]['aliasOf']); |
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156 | 2 | return $this; |
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157 | } |
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158 | |||
159 | /** |
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160 | * Get all of the aliases of the current rule. |
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161 | * |
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162 | * This method is intended to aid in debugging and should not be used in production as it walks the entire rule array. |
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163 | * |
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164 | * @return array Returns an array of strings representing aliases. |
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165 | */ |
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166 | 5 | public function getAliases() { |
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167 | 5 | $result = []; |
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168 | |||
169 | 5 | foreach ($this->rules as $name => $rule) { |
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170 | 1 | if (!empty($rule['aliasOf']) && $rule['aliasOf'] === $this->currentRuleName) { |
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171 | 3 | $result[] = $name; |
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172 | } |
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173 | } |
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174 | |||
175 | 5 | return $result; |
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176 | } |
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177 | |||
178 | /** |
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179 | * Get the factory callback for the current rule. |
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180 | * |
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181 | * @return callable|null Returns the rule's factory or **null** if it has none. |
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182 | */ |
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183 | 2 | public function getFactory() { |
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184 | 2 | return isset($this->currentRule['factory']) ? $this->currentRule['factory'] : null; |
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185 | } |
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186 | |||
187 | /** |
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188 | * Set the factory that will be used to create the instance for the current rule. |
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189 | * |
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190 | * @param callable $factory This callback will be called to create the instance for the rule. |
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191 | * @return $this |
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192 | */ |
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193 | 10 | public function setFactory(callable $factory) { |
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194 | 10 | $this->currentRule['factory'] = $factory; |
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195 | 10 | return $this; |
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196 | 10 | } |
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197 | |||
198 | /** |
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199 | * Whether or not the current rule is shared. |
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200 | * |
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201 | * @return bool Returns **true** if the rule is shared or **false** otherwise. |
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202 | */ |
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203 | 2 | public function isShared() { |
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204 | 2 | return !empty($this->currentRule['shared']); |
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205 | } |
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206 | |||
207 | /** |
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208 | * Set whether or not the current rule is shared. |
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209 | * |
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210 | * @param bool $shared Whether or not the current rule is shared. |
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211 | * @return $this |
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212 | */ |
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213 | 22 | public function setShared($shared) { |
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214 | 22 | $this->currentRule['shared'] = $shared; |
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215 | 22 | return $this; |
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216 | } |
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217 | |||
218 | /** |
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219 | * Whether or not the current rule will inherit to subclasses. |
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220 | * |
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221 | * @return bool Returns **true** if the current rule inherits or **false** otherwise. |
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222 | */ |
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223 | 2 | public function getInherit() { |
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224 | 2 | return !empty($this->currentRule['inherit']); |
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225 | } |
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226 | |||
227 | /** |
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228 | * Set whether or not the current rule extends to subclasses. |
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229 | * |
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230 | * @param bool $inherit Pass **true** to have subclasses inherit this rule or **false** otherwise. |
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231 | * @return $this |
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232 | */ |
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233 | 3 | public function setInherit($inherit) { |
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234 | 3 | $this->currentRule['inherit'] = $inherit; |
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235 | 3 | return $this; |
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236 | } |
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237 | |||
238 | /** |
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239 | * Get the constructor arguments for the current rule. |
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240 | * |
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241 | * @return array Returns the constructor arguments for the current rule. |
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242 | */ |
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243 | 2 | public function getConstructorArgs() { |
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244 | 2 | return empty($this->currentRule['constructorArgs']) ? [] : $this->currentRule['constructorArgs']; |
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245 | } |
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246 | |||
247 | /** |
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248 | * Set the constructor arguments for the current rule. |
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249 | * |
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250 | * @param array $args An array of constructor arguments. |
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251 | * @return $this |
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252 | */ |
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253 | 14 | public function setConstructorArgs(array $args) { |
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254 | 14 | $this->currentRule['constructorArgs'] = $args; |
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255 | 14 | return $this; |
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256 | 14 | } |
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257 | |||
258 | /** |
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259 | * Set a specific shared instance into the container. |
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260 | * |
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261 | * When you set an instance into the container then it will always be returned by subsequent retrievals, even if a |
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262 | * rule is configured that says that instances should not be shared. |
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263 | * |
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264 | * @param string $name The name of the container entry. |
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265 | * @param mixed $instance This instance. |
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266 | * @return $this |
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267 | */ |
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268 | 4 | public function setInstance($name, $instance) { |
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272 | |||
273 | /** |
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274 | * Add a method call to a rule. |
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275 | * |
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276 | * @param string $method The name of the method to call. |
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277 | * @param array $args The arguments to pass to the method. |
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278 | * @return $this |
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279 | */ |
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280 | 3 | public function addCall($method, array $args = []) { |
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281 | 3 | $this->currentRule['calls'][] = [$method, $args]; |
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282 | |||
283 | 3 | return $this; |
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284 | 3 | } |
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285 | |||
286 | /** |
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287 | * Finds an entry of the container by its identifier and returns it. |
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288 | * |
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289 | * @param string $id Identifier of the entry to look for. |
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290 | * @param array $args Additional arguments to pass to the constructor. |
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291 | * |
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292 | * @throws NotFoundException No entry was found for this identifier. |
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293 | * @throws ContainerException Error while retrieving the entry. |
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294 | * |
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295 | * @return mixed Entry. |
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296 | */ |
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297 | 41 | public function getArgs($id, array $args = []) { |
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319 | |||
320 | /** |
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321 | * Make a rule based on an ID. |
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322 | * |
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323 | * @param string $nid A normalized ID. |
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324 | * @return array Returns an array representing a rule. |
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325 | */ |
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326 | 43 | private function makeRule($nid) { |
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376 | |||
377 | /** |
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378 | * Make a function that creates objects from a rule. |
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379 | * |
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380 | * @param string $nid The normalized ID of the container item. |
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381 | * @param array $rule The resolved rule for the ID. |
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382 | * @return \Closure Returns a function that when called will create a new instance of the class. |
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383 | * @throws NotFoundException No entry was found for this identifier. |
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384 | */ |
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385 | 30 | private function makeFactory($nid, array $rule) { |
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455 | |||
456 | /** |
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457 | * Create a shared instance of a class from a rule. |
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458 | * |
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459 | * This method has the side effect of adding the new instance to the internal instances array of this object. |
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460 | * |
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461 | * @param string $nid The normalized ID of the container item. |
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462 | * @param array $rule The resolved rule for the ID. |
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463 | * @param array $args Additional arguments passed during creation. |
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464 | * @return object Returns the the new instance. |
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465 | * @throws NotFoundException Throws an exception if the class does not exist. |
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466 | */ |
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467 | 15 | private function createSharedInstance($nid, array $rule, array $args) { |
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529 | |||
530 | /** |
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531 | * Make an array of default arguments for a given function. |
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532 | * |
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533 | * @param \ReflectionFunctionAbstract $function The function to make the arguments for. |
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534 | * @param array $ruleArgs An array of default arguments specifically for the function. |
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535 | * @param array $rule The entire rule. |
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536 | * @return array Returns an array in the form `name => defaultValue`. |
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537 | */ |
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538 | 29 | private function makeDefaultArgs(\ReflectionFunctionAbstract $function, array $ruleArgs, array $rule = []) { |
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567 | |||
568 | /** |
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569 | * Replace an array of default args with called args. |
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570 | * |
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571 | * @param array $defaultArgs The default arguments from {@link Container::makeDefaultArgs()}. |
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572 | * @param array $args The arguments passed into a creation. |
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573 | * @param mixed $instance An object instance if the arguments are being resolved on an already constructed object. |
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574 | * @return array Returns an array suitable to be applied to a function call. |
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575 | */ |
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576 | 27 | private function resolveArgs(array $defaultArgs, array $args, $instance = null) { |
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601 | |||
602 | /** |
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603 | * Create an instance of a container item. |
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604 | * |
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605 | * This method either creates a new instance or returns an already created shared instance. |
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606 | * |
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607 | * @param string $nid The normalized ID of the container item. |
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608 | * @param array $args Additional arguments to pass to the constructor. |
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609 | * @return object Returns an object instance. |
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610 | */ |
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611 | 43 | private function createInstance($nid, array $args) { |
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624 | |||
625 | /** |
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626 | * Call a callback with argument injection. |
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627 | * |
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628 | * @param callable $callback The callback to call. |
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629 | * @param array $args Additional arguments to pass to the callback. |
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630 | * @return mixed Returns the result of the callback. |
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631 | * @throws ContainerException Throws an exception if the callback cannot be understood. |
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632 | */ |
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633 | 3 | public function call(callable $callback, array $args = []) { |
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650 | |||
651 | /** |
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652 | * Returns true if the container can return an entry for the given identifier. Returns false otherwise. |
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653 | * |
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654 | * @param string $id Identifier of the entry to look for. |
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655 | * |
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656 | * @return boolean |
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657 | */ |
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658 | 2 | public function has($id) { |
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663 | |||
664 | /** |
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665 | * Determines whether a rule has been defined at a given ID. |
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666 | * |
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667 | * @param string $id Identifier of the entry to look for. |
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668 | * @return bool Returns **true** if a rule has been defined or **false** otherwise. |
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669 | */ |
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670 | 2 | public function hasRule($id) { |
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674 | |||
675 | /** |
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676 | * Finds an entry of the container by its identifier and returns it. |
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677 | * |
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678 | * @param string $id Identifier of the entry to look for. |
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679 | * |
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680 | * @throws NotFoundException No entry was found for this identifier. |
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681 | * @throws ContainerException Error while retrieving the entry. |
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682 | * |
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683 | * @return mixed Entry. |
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684 | */ |
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685 | 2 | public function get($id) { |
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688 | |||
689 | /** |
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690 | * Determine the reflection information for a callback. |
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691 | * |
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692 | * @param callable $callback The callback to reflect. |
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693 | * @return \ReflectionFunctionAbstract Returns the reflection function for the callback. |
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694 | */ |
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695 | 9 | private function reflectCallback(callable $callback) { |
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702 | } |
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703 |
This check compares the return type specified in the
@return
annotation of a function or method doc comment with the types returned by the function and raises an issue if they mismatch.