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 MultiForm 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 MultiForm, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 17 | abstract class MultiForm extends Form { |
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| 18 | |||
| 19 | /** |
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| 20 | * A session object stored in the database, to identify and store |
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| 21 | * data for this MultiForm instance. |
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| 22 | * |
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| 23 | * @var MultiFormSession |
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| 24 | */ |
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| 25 | protected $session; |
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| 26 | |||
| 27 | /** |
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| 28 | * The current encrypted MultiFormSession identification. |
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| 29 | * |
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| 30 | * @var string |
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| 31 | */ |
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| 32 | protected $currentSessionHash; |
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| 33 | |||
| 34 | /** |
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| 35 | * Defines which subclass of {@link MultiFormStep} should be the first |
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| 36 | * step in the multi-step process. |
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| 37 | * |
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| 38 | * @var string Classname of a {@link MultiFormStep} subclass |
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| 39 | */ |
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| 40 | public static $start_step; |
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| 41 | |||
| 42 | /** |
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| 43 | * Set the casting for these fields. |
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| 44 | * |
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| 45 | * @var array |
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| 46 | */ |
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| 47 | private static $casting = array( |
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| 48 | 'CompletedStepCount' => 'Int', |
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| 49 | 'TotalStepCount' => 'Int', |
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| 50 | 'CompletedPercent' => 'Float' |
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| 51 | ); |
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| 52 | |||
| 53 | /** |
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| 54 | * @var string |
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| 55 | */ |
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| 56 | private static $get_var = 'MultiFormSessionID'; |
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| 57 | /** |
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| 58 | * These fields are ignored when saving the raw form data into session. |
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| 59 | * This ensures only field data is saved, and nothing else that's useless |
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| 60 | * or potentially dangerous. |
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| 61 | * |
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| 62 | * @var array |
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| 63 | */ |
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| 64 | public static $ignored_fields = array( |
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| 65 | 'url', |
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| 66 | 'executeForm', |
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| 67 | 'SecurityID' |
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| 68 | ); |
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| 69 | |||
| 70 | /** |
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| 71 | * Any of the actions defined in this variable are exempt from |
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| 72 | * being validated. |
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| 73 | * |
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| 74 | * This is most useful for the "Back" (action_prev) action, as |
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| 75 | * you typically don't validate the form when the user is going |
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| 76 | * back a step. |
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| 77 | * |
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| 78 | * @var array |
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| 79 | */ |
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| 80 | public static $actions_exempt_from_validation = array( |
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| 81 | 'action_prev' |
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| 82 | ); |
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| 83 | |||
| 84 | /** |
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| 85 | * @var string |
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| 86 | */ |
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| 87 | protected $displayLink; |
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| 88 | |||
| 89 | /** |
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| 90 | * Flag which is being used in getAllStepsRecursive() to allow adding the completed flag on the steps |
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| 91 | * |
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| 92 | * @var boolean |
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| 93 | */ |
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| 94 | protected $currentStepHasBeenFound = false; |
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| 95 | |||
| 96 | /** |
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| 97 | * Start the MultiForm instance. |
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| 98 | * |
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| 99 | * @param Controller instance $controller Controller this form is created on |
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| 100 | * @param string $name The form name, typically the same as the method name |
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| 101 | */ |
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| 102 | public function __construct($controller, $name) { |
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| 168 | |||
| 169 | /** |
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| 170 | * Accessor method to $this->controller. |
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| 171 | * |
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| 172 | * @return Controller this MultiForm was instanciated on. |
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| 173 | */ |
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| 174 | public function getController() { |
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| 177 | |||
| 178 | /** |
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| 179 | * Returns the get_var to the template engine |
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| 180 | * |
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| 181 | * @return string |
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| 182 | */ |
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| 183 | public function getGetVar() { |
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| 184 | return $this->config()->get_var; |
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| 185 | } |
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| 186 | |||
| 187 | /** |
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| 188 | * Get the current step. |
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| 189 | * |
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| 190 | * If StepID has been set in the URL, we attempt to get that record |
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| 191 | * by the ID. Otherwise, we check if there's a current step ID in |
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| 192 | * our session record. Failing those cases, we assume that the form has |
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| 193 | * just been started, and so we create the first step and return it. |
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| 194 | * |
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| 195 | * @return MultiFormStep subclass |
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| 196 | */ |
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| 197 | public function getCurrentStep() { |
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| 229 | |||
| 230 | /** |
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| 231 | * Set the step passed in as the current step. |
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| 232 | * |
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| 233 | * @param MultiFormStep $step A subclass of MultiFormStep |
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| 234 | * @return boolean The return value of write() |
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| 235 | */ |
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| 236 | protected function setCurrentStep($step) { |
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| 242 | |||
| 243 | /** |
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| 244 | * Accessor method to $this->session. |
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| 245 | * |
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| 246 | * @return MultiFormSession |
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| 247 | */ |
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| 248 | public function getSession() { |
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| 251 | |||
| 252 | /** |
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| 253 | * Set up the session. |
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| 254 | * |
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| 255 | * If MultiFormSessionID isn't set, we assume that this is a new |
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| 256 | * multiform that requires a new session record to be created. |
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| 257 | * |
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| 258 | * @TODO Fix the fact you can continually refresh and create new records |
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| 259 | * if MultiFormSessionID isn't set. |
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| 260 | * |
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| 261 | * @TODO Not sure if we should bake the session stuff directly into MultiForm. |
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| 262 | * Perhaps it would be best dealt with on a separate class? |
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| 263 | */ |
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| 264 | protected function setSession() { |
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| 278 | |||
| 279 | /** |
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| 280 | * Set the currently used encrypted hash to identify |
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| 281 | * the MultiFormSession. |
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| 282 | * |
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| 283 | * @param string $hash Encrypted identification to session |
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| 284 | */ |
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| 285 | public function setCurrentSessionHash($hash) { |
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| 289 | |||
| 290 | /** |
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| 291 | * Return the currently used {@link MultiFormSession} |
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| 292 | * @return MultiFormSession|boolean FALSE |
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| 293 | */ |
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| 294 | public function getCurrentSession() { |
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| 310 | |||
| 311 | /** |
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| 312 | * Get all steps saved in the database for the currently active session, |
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| 313 | * in the order they were saved, oldest to newest (automatically ordered by ID). |
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| 314 | * If you want a full chain of steps regardless if they've already been saved |
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| 315 | * to the database, use {@link getAllStepsLinear()}. |
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| 316 | * |
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| 317 | * @param string $filter SQL WHERE statement |
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| 318 | * @return DataObjectSet|boolean A set of MultiFormStep subclasses |
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| 319 | */ |
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| 320 | public function getSavedSteps($filter = null) { |
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| 325 | |||
| 326 | /** |
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| 327 | * Get a step which was previously saved to the database in the current session. |
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| 328 | * Caution: This might cause unexpected behaviour if you have multiple steps |
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| 329 | * in your chain with the same classname. |
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| 330 | * |
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| 331 | * @param string $className Classname of a {@link MultiFormStep} subclass |
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| 332 | * @return MultiFormStep |
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| 333 | */ |
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| 334 | public function getSavedStepByClass($className) { |
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| 343 | |||
| 344 | /** |
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| 345 | * Build a FieldList of the FormAction fields for the given step. |
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| 346 | * |
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| 347 | * If the current step is the final step, we push in a submit button, which |
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| 348 | * calls the action {@link finish()} to finalise the submission. Otherwise, |
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| 349 | * we push in a next button which calls the action {@link next()} to determine |
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| 350 | * where to go next in our step process, and save any form data collected. |
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| 351 | * |
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| 352 | * If there's a previous step (a step that has the current step as it's next |
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| 353 | * step class), then we allow a previous button, which calls the previous action |
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| 354 | * to determine which step to go back to. |
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| 355 | * |
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| 356 | * If there are any extra actions defined in MultiFormStep->getExtraActions() |
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| 357 | * then that set of actions is appended to the end of the actions FieldSet we |
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| 358 | * have created in this method. |
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| 359 | * |
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| 360 | * @param $currentStep Subclass of MultiFormStep |
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| 361 | * @return FieldList of FormAction objects |
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| 362 | */ |
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| 363 | public function actionsFor($step) { |
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| 393 | |||
| 394 | /** |
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| 395 | * Return a rendered version of this form, with a specific template. |
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| 396 | * Looks through the step ancestory templates (MultiFormStep, current step |
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| 397 | * subclass template) to see if one is available to render the form with. If |
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| 398 | * any of those don't exist, look for a default Form template to render |
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| 399 | * with instead. |
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| 400 | * |
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| 401 | * @return SSViewer object to render the template with |
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| 402 | */ |
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| 403 | public function forTemplate() { |
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| 416 | |||
| 417 | /** |
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| 418 | * This method saves the data on the final step, after submitting. |
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| 419 | * It should always be overloaded with parent::finish($data, $form) |
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| 420 | * so you can create your own functionality which handles saving |
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| 421 | * of all the data collected through each step of the form. |
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| 422 | * |
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| 423 | * @param array $data The request data returned from the form |
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| 424 | * @param object $form The form that the action was called on |
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| 425 | */ |
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| 426 | public function finish($data, $form) { |
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| 441 | |||
| 442 | /** |
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| 443 | * Determine what to do when the next action is called. |
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| 444 | * |
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| 445 | * Saves the current step session data to the database, creates the |
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| 446 | * new step based on getNextStep() of the current step (or fetches |
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| 447 | * an existing one), resets the current step to the next step, |
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| 448 | * then redirects to the newly set step. |
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| 449 | * |
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| 450 | * @param array $data The request data returned from the form |
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| 451 | * @param object $form The form that the action was called on |
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| 452 | */ |
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| 453 | public function next($data, $form) { |
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| 490 | |||
| 491 | /** |
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| 492 | * Determine what to do when the previous action is called. |
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| 493 | * |
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| 494 | * Retrieves the previous step class, finds the record for that |
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| 495 | * class in the DB, and sets the current step to that step found. |
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| 496 | * Finally, it redirects to that step. |
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| 497 | * |
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| 498 | * @param array $data The request data returned from the form |
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| 499 | * @param object $form The form that the action was called on |
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| 500 | */ |
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| 501 | public function prev($data, $form) { |
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| 522 | |||
| 523 | /** |
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| 524 | * Save the raw data given back from the form into session. |
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| 525 | * |
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| 526 | * Take the submitted form data for the current step, removing |
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| 527 | * any key => value pairs that shouldn't be saved, then saves |
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| 528 | * the data into the session. |
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| 529 | * |
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| 530 | * @param array $data An array of data to save |
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| 531 | */ |
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| 532 | protected function save($data) { |
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| 544 | |||
| 545 | // ############ Misc ############ |
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| 546 | |||
| 547 | /** |
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| 548 | * Add the MultiFormSessionID variable to the URL on form submission. |
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| 549 | * This is a means to persist the session, by adding it's identification |
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| 550 | * to the URL, which ties it back to this MultiForm instance. |
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| 551 | * |
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| 552 | * @return string |
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| 553 | */ |
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| 554 | public function FormAction() { |
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| 561 | |||
| 562 | /** |
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| 563 | * Returns the link to the page where the form is displayed. The user is |
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| 564 | * redirected to this link with a session param after each step is |
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| 565 | * submitted. |
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| 566 | * |
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| 567 | * @return string |
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| 568 | */ |
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| 569 | public function getDisplayLink() { |
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| 572 | |||
| 573 | /** |
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| 574 | * Set the link to the page on which the form is displayed. |
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| 575 | * |
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| 576 | * The link defaults to the controllers current link. However if the form |
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| 577 | * is displayed inside an action the display link must be explicitly set. |
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| 578 | * |
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| 579 | * @param string $link |
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| 580 | */ |
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| 581 | public function setDisplayLink($link) { |
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| 584 | |||
| 585 | /** |
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| 586 | * Determine the steps to show in a linear fashion, starting from the |
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| 587 | * first step. We run {@link getAllStepsRecursive} passing the steps found |
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| 588 | * by reference to get a listing of the steps. |
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| 589 | * |
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| 590 | * @return DataObjectSet of MultiFormStep instances |
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| 591 | */ |
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| 592 | public function getAllStepsLinear() { |
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| 608 | |||
| 609 | /** |
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| 610 | * Recursively run through steps using the getNextStep() method on each step |
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| 611 | * to determine what the next step is, gathering each step along the way. |
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| 612 | * We stop on the last step, and return the results. |
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| 613 | * If a step in the chain was already saved to the database in the current |
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| 614 | * session, its used - otherwise a singleton of this step is used. |
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| 615 | * Caution: Doesn't consider branching for steps which aren't in the database yet. |
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| 616 | * |
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| 617 | * @param $step Subclass of MultiFormStep to find the next step of |
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| 618 | * @param $stepsFound $stepsFound DataObjectSet reference, the steps found to call back on |
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| 619 | * @return DataObjectSet of MultiFormStep instances |
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| 620 | */ |
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| 621 | protected function getAllStepsRecursive($step, &$stepsFound) { |
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| 652 | |||
| 653 | /** |
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| 654 | * Number of steps already completed (excluding currently started step). |
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| 655 | * The way we determine a step is complete is to check if it has the Data |
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| 656 | * field filled out with a serialized value, then we know that the user has |
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| 657 | * clicked next on the given step, to proceed. |
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| 658 | * |
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| 659 | * @TODO Not sure if it's entirely appropriate to check if Data is set as a |
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| 660 | * way to determine a step is "completed". |
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| 661 | * |
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| 662 | * @return int |
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| 663 | */ |
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| 664 | public function getCompletedStepCount() { |
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| 669 | |||
| 670 | /** |
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| 671 | * Total number of steps in the shortest path (only counting straight path without any branching) |
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| 672 | * The way we determine this is to check if each step has a next_step string variable set. If it's |
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| 673 | * anything else (like an array, for defining multiple branches) then it gets counted as a single step. |
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| 674 | * |
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| 675 | * @return int |
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| 676 | */ |
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| 677 | public function getTotalStepCount() { |
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| 680 | |||
| 681 | /** |
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| 682 | * Percentage of steps completed (excluding currently started step) |
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| 683 | * |
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| 684 | * @return float |
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| 685 | */ |
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| 686 | public function getCompletedPercent() { |
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| 689 | } |
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| 690 |
You can fix this by adding a namespace to your class:
When choosing a vendor namespace, try to pick something that is not too generic to avoid conflicts with other libraries.