Complex classes like ViewableData 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 ViewableData, and based on these observations, apply Extract Interface, too.
1 | <?php |
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15 | class ViewableData extends Object implements IteratorAggregate { |
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16 | |||
17 | /** |
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18 | * An array of objects to cast certain fields to. This is set up as an array in the format: |
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19 | * |
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20 | * <code> |
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21 | * public static $casting = array ( |
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22 | * 'FieldName' => 'ClassToCastTo(Arguments)' |
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23 | * ); |
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24 | * </code> |
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25 | * |
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26 | * @var array |
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27 | * @config |
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28 | */ |
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29 | private static $casting = array( |
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30 | 'CSSClasses' => 'Varchar' |
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31 | ); |
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32 | |||
33 | /** |
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34 | * The default object to cast scalar fields to if casting information is not specified, and casting to an object |
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35 | * is required. |
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36 | * |
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37 | * @var string |
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38 | * @config |
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39 | */ |
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40 | private static $default_cast = 'Text'; |
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41 | |||
42 | /** |
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43 | * @var array |
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44 | */ |
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45 | private static $casting_cache = array(); |
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46 | |||
47 | // ----------------------------------------------------------------------------------------------------------------- |
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48 | |||
49 | /** |
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50 | * A failover object to attempt to get data from if it is not present on this object. |
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51 | * |
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52 | * @var ViewableData |
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53 | */ |
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54 | protected $failover; |
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55 | |||
56 | /** |
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57 | * @var ViewableData |
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58 | */ |
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59 | protected $customisedObject; |
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60 | |||
61 | /** |
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62 | * @var array |
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63 | */ |
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64 | private $objCache = array(); |
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65 | |||
66 | // ----------------------------------------------------------------------------------------------------------------- |
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67 | |||
68 | /** |
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69 | * Converts a field spec into an object creator. For example: "Int" becomes "new Int($fieldName);" and "Varchar(50)" |
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70 | * becomes "new DBVarchar($fieldName, 50);". |
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71 | * |
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72 | * @param string $fieldSchema The field spec |
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73 | * @return string |
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74 | */ |
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75 | public static function castingObjectCreator($fieldSchema) { |
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78 | |||
79 | /** |
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80 | * Convert a field schema (e.g. "Varchar(50)") into a casting object creator array that contains both a className |
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81 | * and castingHelper constructor code. See {@link castingObjectCreator} for more information about the constructor. |
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82 | * |
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83 | * @param string $fieldSchema |
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84 | * @return array |
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85 | */ |
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86 | public static function castingObjectCreatorPair($fieldSchema) { |
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89 | |||
90 | // FIELD GETTERS & SETTERS ----------------------------------------------------------------------------------------- |
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91 | |||
92 | /** |
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93 | * Check if a field exists on this object or its failover. |
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94 | * |
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95 | * @param string $property |
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96 | * @return bool |
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97 | */ |
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98 | public function __isset($property) { |
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101 | |||
102 | /** |
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103 | * Get the value of a property/field on this object. This will check if a method called get{$property} exists, then |
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104 | * check if a field is available using {@link ViewableData::getField()}, then fall back on a failover object. |
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105 | * |
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106 | * @param string $property |
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107 | * @return mixed |
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108 | */ |
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109 | public function __get($property) { |
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118 | |||
119 | /** |
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120 | * Set a property/field on this object. This will check for the existence of a method called set{$property}, then |
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121 | * use the {@link ViewableData::setField()} method. |
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122 | * |
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123 | * @param string $property |
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124 | * @param mixed $value |
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125 | */ |
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126 | public function __set($property, $value) { |
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133 | |||
134 | /** |
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135 | * Set a failover object to attempt to get data from if it is not present on this object. |
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136 | * |
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137 | * @param ViewableData $failover |
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138 | */ |
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139 | public function setFailover(ViewableData $failover) { |
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143 | |||
144 | /** |
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145 | * Get the current failover object if set |
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146 | * |
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147 | * @return ViewableData|null |
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148 | */ |
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149 | public function getFailover() { |
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152 | |||
153 | /** |
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154 | * Check if a field exists on this object. This should be overloaded in child classes. |
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155 | * |
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156 | * @param string $field |
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157 | * @return bool |
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158 | */ |
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159 | public function hasField($field) { |
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162 | |||
163 | /** |
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164 | * Get the value of a field on this object. This should be overloaded in child classes. |
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165 | * |
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166 | * @param string $field |
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167 | * @return mixed |
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168 | */ |
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169 | public function getField($field) { |
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172 | |||
173 | /** |
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174 | * Set a field on this object. This should be overloaded in child classes. |
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175 | * |
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176 | * @param string $field |
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177 | * @param mixed $value |
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178 | */ |
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179 | public function setField($field, $value) { |
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182 | |||
183 | // ----------------------------------------------------------------------------------------------------------------- |
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184 | |||
185 | /** |
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186 | * Add methods from the {@link ViewableData::$failover} object, as well as wrapping any methods prefixed with an |
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187 | * underscore into a {@link ViewableData::cachedCall()}. |
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188 | */ |
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189 | public function defineMethods() { |
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201 | |||
202 | /** |
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203 | * Merge some arbitrary data in with this object. This method returns a {@link ViewableData_Customised} instance |
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204 | * with references to both this and the new custom data. |
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205 | * |
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206 | * Note that any fields you specify will take precedence over the fields on this object. |
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207 | * |
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208 | * @param array|ViewableData $data |
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209 | * @return ViewableData_Customised |
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210 | */ |
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211 | public function customise($data) { |
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224 | |||
225 | /** |
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226 | * @return ViewableData |
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227 | */ |
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228 | public function getCustomisedObj() { |
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231 | |||
232 | /** |
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233 | * @param ViewableData $object |
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234 | */ |
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235 | public function setCustomisedObj(ViewableData $object) { |
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238 | |||
239 | // CASTING --------------------------------------------------------------------------------------------------------- |
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240 | |||
241 | /** |
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242 | * Get the class a field on this object would be casted to, as well as the casting helper for casting a field to |
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243 | * an object (see {@link ViewableData::castingHelper()} for information on casting helpers). |
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244 | * |
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245 | * The returned array contains two keys: |
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246 | * - className: the class the field would be casted to (e.g. "Varchar") |
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247 | * - castingHelper: the casting helper for casting the field (e.g. "return new Varchar($fieldName)") |
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248 | * |
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249 | * @param string $field |
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250 | * @return array |
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251 | */ |
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252 | public function castingHelperPair($field) { |
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256 | |||
257 | /** |
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258 | * Return the "casting helper" (a piece of PHP code that when evaluated creates a casted value object) for a field |
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259 | * on this object. |
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260 | * |
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261 | * @param string $field |
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262 | * @return string Casting helper |
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263 | */ |
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264 | public function castingHelper($field) { |
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272 | |||
273 | /** |
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274 | * Get the class name a field on this object will be casted to |
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275 | * |
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276 | * @param string $field |
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277 | * @return string |
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278 | */ |
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279 | public function castingClass($field) { |
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287 | |||
288 | /** |
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289 | * Return the string-format type for the given field. |
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290 | * |
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291 | * @param string $field |
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292 | * @return string 'xml'|'raw' |
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293 | */ |
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294 | public function escapeTypeForField($field) { |
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301 | |||
302 | /** |
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303 | * Save the casting cache for this object (including data from any failovers) into a variable |
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304 | * |
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305 | * @param reference $cache |
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306 | */ |
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307 | public function buildCastingCache(&$cache) { |
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330 | |||
331 | // TEMPLATE ACCESS LAYER ------------------------------------------------------------------------------------------- |
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332 | |||
333 | /** |
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334 | * Render this object into the template, and get the result as a string. You can pass one of the following as the |
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335 | * $template parameter: |
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336 | * - a template name (e.g. Page) |
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337 | * - an array of possible template names - the first valid one will be used |
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338 | * - an SSViewer instance |
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339 | * |
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340 | * @param string|array|SSViewer $template the template to render into |
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341 | * @param array $customFields fields to customise() the object with before rendering |
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342 | * @return HTMLText |
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343 | */ |
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344 | public function renderWith($template, $customFields = null) { |
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362 | |||
363 | /** |
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364 | * Generate the cache name for a field |
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365 | * |
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366 | * @param string $fieldName Name of field |
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367 | * @param array $arguments List of optional arguments given |
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368 | */ |
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369 | protected function objCacheName($fieldName, $arguments) { |
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374 | |||
375 | /** |
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376 | * Get a cached value from the field cache |
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377 | * |
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378 | * @param string $key Cache key |
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379 | * @return mixed |
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380 | */ |
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381 | protected function objCacheGet($key) { |
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384 | |||
385 | /** |
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386 | * Store a value in the field cache |
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387 | * |
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388 | * @param string $key Cache key |
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389 | * @param mixed $value |
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390 | */ |
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391 | protected function objCacheSet($key, $value) { |
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394 | |||
395 | /** |
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396 | * Get the value of a field on this object, automatically inserting the value into any available casting objects |
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397 | * that have been specified. |
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398 | * |
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399 | * @param string $fieldName |
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400 | * @param array $arguments |
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401 | * @param bool $forceReturnedObject if TRUE, the value will ALWAYS be casted to an object before being returned, |
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402 | * even if there is no explicit casting information |
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403 | * @param bool $cache Cache this object |
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404 | * @param string $cacheName a custom cache name |
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405 | */ |
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406 | public function obj($fieldName, $arguments = null, $forceReturnedObject = true, $cache = false, $cacheName = null) { |
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444 | |||
445 | /** |
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446 | * A simple wrapper around {@link ViewableData::obj()} that automatically caches the result so it can be used again |
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447 | * without re-running the method. |
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448 | * |
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449 | * @param string $field |
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450 | * @param array $arguments |
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451 | * @param string $identifier an optional custom cache identifier |
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452 | */ |
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453 | public function cachedCall($field, $arguments = null, $identifier = null) { |
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456 | |||
457 | /** |
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458 | * Checks if a given method/field has a valid value. If the result is an object, this will return the result of the |
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459 | * exists method, otherwise will check if the result is not just an empty paragraph tag. |
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460 | * |
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461 | * @param string $field |
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462 | * @param array $arguments |
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463 | * @param bool $cache |
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464 | * @return bool |
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465 | */ |
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466 | public function hasValue($field, $arguments = null, $cache = true) { |
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476 | |||
477 | /**#@+ |
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478 | * @param string $field |
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479 | * @param array $arguments |
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480 | * @param bool $cache |
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481 | * @return string |
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482 | */ |
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483 | |||
484 | /** |
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485 | * Get the string value of a field on this object that has been suitable escaped to be inserted directly into a |
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486 | * template. |
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487 | */ |
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488 | public function XML_val($field, $arguments = null, $cache = false) { |
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492 | |||
493 | /** |
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494 | * Return the value of the field without any escaping being applied. |
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495 | */ |
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496 | public function RAW_val($field, $arguments = null, $cache = true) { |
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499 | |||
500 | /** |
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501 | * Return the value of a field in an SQL-safe format. |
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502 | */ |
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503 | public function SQL_val($field, $arguments = null, $cache = true) { |
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506 | |||
507 | /** |
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508 | * Return the value of a field in a JavaScript-save format. |
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509 | */ |
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510 | public function JS_val($field, $arguments = null, $cache = true) { |
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513 | |||
514 | /** |
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515 | * Return the value of a field escaped suitable to be inserted into an XML node attribute. |
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516 | */ |
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517 | public function ATT_val($field, $arguments = null, $cache = true) { |
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520 | |||
521 | /**#@-*/ |
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522 | |||
523 | /** |
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524 | * Get an array of XML-escaped values by field name |
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525 | * |
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526 | * @param array $elements an array of field names |
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527 | * @return array |
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528 | */ |
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529 | public function getXMLValues($fields) { |
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538 | |||
539 | // ITERATOR SUPPORT ------------------------------------------------------------------------------------------------ |
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540 | |||
541 | /** |
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542 | * Return a single-item iterator so you can iterate over the fields of a single record. |
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543 | * |
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544 | * This is useful so you can use a single record inside a <% control %> block in a template - and then use |
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545 | * to access individual fields on this object. |
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546 | * |
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547 | * @return ArrayIterator |
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548 | */ |
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549 | public function getIterator() { |
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552 | |||
553 | // UTILITY METHODS ------------------------------------------------------------------------------------------------- |
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554 | |||
555 | /** |
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556 | * When rendering some objects it is necessary to iterate over the object being rendered, to do this, you need |
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557 | * access to itself. |
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558 | * |
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559 | * @return ViewableData |
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560 | */ |
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561 | public function Me() { |
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564 | |||
565 | /** |
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566 | * Return the directory if the current active theme (relative to the site root). |
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567 | * |
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568 | * This method is useful for things such as accessing theme images from your template without hardcoding the theme |
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569 | * page - e.g. <img src="$ThemeDir/images/something.gif">. |
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570 | * |
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571 | * This method should only be used when a theme is currently active. However, it will fall over to the current |
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572 | * project directory. |
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573 | * |
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574 | * @param string $subtheme the subtheme path to get |
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575 | * @return string |
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576 | */ |
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577 | public function ThemeDir($subtheme = false) { |
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587 | |||
588 | /** |
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589 | * Get part of the current classes ancestry to be used as a CSS class. |
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590 | * |
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591 | * This method returns an escaped string of CSS classes representing the current classes ancestry until it hits a |
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592 | * stop point - e.g. "Page DataObject ViewableData". |
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593 | * |
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594 | * @param string $stopAtClass the class to stop at (default: ViewableData) |
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595 | * @return string |
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596 | * @uses ClassInfo |
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597 | */ |
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598 | public function CSSClasses($stopAtClass = 'ViewableData') { |
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615 | |||
616 | /** |
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617 | * Return debug information about this object that can be rendered into a template |
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618 | * |
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619 | * @return ViewableData_Debugger |
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620 | */ |
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621 | public function Debug() { |
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624 | |||
625 | } |
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626 | |||
782 |
This check looks from parameters that have been defined for a function or method, but which are not used in the method body.