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 CommentsExtension 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 CommentsExtension, and based on these observations, apply Extract Interface, too.
1 | <?php |
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33 | class CommentsExtension extends DataExtension |
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34 | { |
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35 | /** |
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36 | * Default configuration values |
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37 | * |
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38 | * enabled: Allows commenting to be disabled even if the extension is present |
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39 | * enabled_cms: Allows commenting to be enabled or disabled via the CMS |
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40 | * require_login: Boolean, whether a user needs to login (required for required_permission) |
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41 | * require_login_cms: Allows require_login to be set via the CMS |
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42 | * required_permission: Permission (or array of permissions) required to comment |
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43 | * include_js: Enhance operation by ajax behaviour on moderation links (required for use_preview) |
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44 | * use_gravatar: Set to true to show gravatar icons |
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45 | * gravatar_default: Theme for 'not found' gravatar {@see http://gravatar.com/site/implement/images} |
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46 | * gravatar_rating: Gravatar rating (same as the standard default) |
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47 | * show_comments_when_disabled: Show older comments when commenting has been disabled. |
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48 | * order_comments_by: Default sort order. |
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49 | * order_replies_by: Sort order for replies. |
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50 | * comments_holder_id: ID for the comments holder |
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51 | * comment_permalink_prefix: ID prefix for each comment |
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52 | * require_moderation: Require moderation for all comments |
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53 | * require_moderation_cms: Ignore other comment moderation config settings and set via CMS |
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54 | * frontend_moderation: Display unmoderated comments in the frontend, if the user can moderate them. |
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55 | * frontend_spam: Display spam comments in the frontend, if the user can moderate them. |
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56 | * html_allowed: Allow for sanitized HTML in comments |
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57 | * use_preview: Preview formatted comment (when allowing HTML) |
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58 | * nested_comments: Enable nested comments |
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59 | * nested_depth: Max depth of nested comments in levels (where root is 1 depth) 0 means no limit. |
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60 | * |
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61 | * @var array |
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62 | * |
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63 | * @config |
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64 | */ |
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65 | private static $comments = [ |
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66 | 'enabled' => true, |
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67 | 'enabled_cms' => false, |
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68 | 'require_login' => false, |
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69 | 'require_login_cms' => false, |
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70 | 'required_permission' => false, |
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71 | 'include_js' => true, |
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72 | 'use_gravatar' => false, |
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73 | 'gravatar_size' => 80, |
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74 | 'gravatar_default' => 'identicon', |
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75 | 'gravatar_rating' => 'g', |
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76 | 'show_comments_when_disabled' => false, |
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77 | 'order_comments_by' => '"Created" DESC', |
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78 | 'order_replies_by' => false, |
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79 | 'comments_per_page' => 10, |
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80 | 'comments_holder_id' => 'comments-holder', |
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81 | 'comment_permalink_prefix' => 'comment-', |
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82 | 'require_moderation' => false, |
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83 | 'require_moderation_nonmembers' => false, |
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84 | 'require_moderation_cms' => false, |
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85 | 'frontend_moderation' => false, |
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86 | 'frontend_spam' => false, |
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87 | 'html_allowed' => false, |
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88 | 'html_allowed_elements' => ['a', 'img', 'i', 'b'], |
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89 | 'use_preview' => false, |
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90 | 'nested_comments' => false, |
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91 | 'nested_depth' => 2, |
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92 | ]; |
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93 | |||
94 | /** |
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95 | * @var array |
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96 | */ |
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97 | private static $db = [ |
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98 | 'ProvideComments' => 'Boolean', |
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99 | 'ModerationRequired' => 'Enum(\'None,Required,NonMembersOnly\',\'None\')', |
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100 | 'CommentsRequireLogin' => 'Boolean', |
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101 | ]; |
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102 | |||
103 | /** |
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104 | * {@inheritDoc} |
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105 | */ |
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106 | private static $has_many = [ |
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107 | 'Commments' => Comment::class . '.Parent' |
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108 | ]; |
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109 | |||
110 | /** |
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111 | * CMS configurable options should default to the config values, but respect |
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112 | * default values specified by the object |
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113 | */ |
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114 | public function populateDefaults() |
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115 | { |
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116 | $defaults = $this->owner->config()->get('defaults'); |
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117 | |||
118 | // Set if comments should be enabled by default |
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119 | View Code Duplication | if (isset($defaults['ProvideComments'])) { |
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120 | $this->owner->ProvideComments = $defaults['ProvideComments']; |
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121 | } else { |
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122 | $this->owner->ProvideComments = $this->owner->getCommentsOption('enabled') ? 1 : 0; |
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123 | } |
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124 | |||
125 | // If moderation options should be configurable via the CMS then |
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126 | if (isset($defaults['ModerationRequired'])) { |
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127 | $this->owner->ModerationRequired = $defaults['ModerationRequired']; |
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128 | } elseif ($this->owner->getCommentsOption('require_moderation')) { |
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129 | $this->owner->ModerationRequired = 'Required'; |
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130 | } elseif ($this->owner->getCommentsOption('require_moderation_nonmembers')) { |
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131 | $this->owner->ModerationRequired = 'NonMembersOnly'; |
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132 | } else { |
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133 | $this->owner->ModerationRequired = 'None'; |
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134 | } |
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135 | |||
136 | // Set login required |
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137 | View Code Duplication | if (isset($defaults['CommentsRequireLogin'])) { |
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138 | $this->owner->CommentsRequireLogin = $defaults['CommentsRequireLogin']; |
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139 | } else { |
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140 | $this->owner->CommentsRequireLogin = $this->owner->getCommentsOption('require_login') ? 1 : 0; |
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141 | } |
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142 | } |
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143 | |||
144 | |||
145 | /** |
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146 | * If this extension is applied to a {@link SiteTree} record then |
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147 | * append a Provide Comments checkbox to allow authors to trigger |
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148 | * whether or not to display comments |
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149 | * |
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150 | * @todo Allow customization of other {@link Commenting} configuration |
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151 | * |
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152 | * @param FieldList $fields |
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153 | */ |
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154 | public function updateSettingsFields(FieldList $fields) |
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198 | |||
199 | /** |
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200 | * Get comment moderation rules for this parent |
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201 | * |
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202 | * None: No moderation required |
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203 | * Required: All comments |
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204 | * NonMembersOnly: Only anonymous users |
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205 | * |
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206 | * @return string |
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207 | */ |
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208 | public function getModerationRequired() |
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220 | |||
221 | /** |
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222 | * Determine if users must be logged in to post comments |
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223 | * |
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224 | * @return boolean |
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225 | */ |
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226 | public function getCommentsRequireLogin() |
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234 | |||
235 | /** |
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236 | * Returns the RelationList of all comments against this object. Can be used as a data source |
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237 | * for a gridfield with write access. |
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238 | * |
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239 | * @return DataList |
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240 | */ |
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241 | View Code Duplication | public function AllComments() |
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250 | |||
251 | /** |
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252 | * Returns all comments against this object, with with spam and unmoderated items excluded, for use in the frontend |
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253 | * |
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254 | * @return DataList |
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255 | */ |
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256 | public function AllVisibleComments() |
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277 | |||
278 | /** |
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279 | * Returns the root level comments, with spam and unmoderated items excluded, for use in the frontend |
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280 | * |
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281 | * @return DataList |
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282 | */ |
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283 | View Code Duplication | public function Comments() |
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295 | |||
296 | /** |
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297 | * Returns a paged list of the root level comments, with spam and unmoderated items excluded, |
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298 | * for use in the frontend |
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299 | * |
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300 | * @return PaginatedList |
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301 | */ |
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302 | View Code Duplication | public function PagedComments() |
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314 | |||
315 | /** |
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316 | * Determine if comments are enabled for this instance |
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317 | * |
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318 | * @return boolean |
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319 | */ |
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320 | public function getCommentsEnabled() |
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334 | |||
335 | /** |
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336 | * Get the HTML ID for the comment holder in the template |
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337 | * |
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338 | * @return string |
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339 | */ |
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340 | public function getCommentHolderID() |
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344 | |||
345 | /** |
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346 | * Permission codes required in order to post (or empty if none required) |
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347 | * |
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348 | * @return string|array Permission or list of permissions, if required |
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349 | */ |
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350 | public function getPostingRequiredPermission() |
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354 | |||
355 | /** |
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356 | * Determine if a user can post comments on this item |
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357 | * |
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358 | * @param Member $member Member to check |
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359 | * |
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360 | * @return boolean |
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361 | */ |
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362 | public function canPostComment($member = null) |
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394 | |||
395 | /** |
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396 | * Determine if this member can moderate comments in the CMS |
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397 | * |
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398 | * @param Member $member |
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399 | * |
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400 | * @return boolean |
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401 | */ |
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402 | public function canModerateComments($member = null) |
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412 | |||
413 | /** |
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414 | * Gets the RSS link to all comments |
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415 | * |
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416 | * @return string |
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417 | */ |
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418 | public function getCommentRSSLink() |
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422 | |||
423 | /** |
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424 | * Get the RSS link to all comments on this page |
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425 | * |
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426 | * @return string |
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427 | */ |
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428 | public function getCommentRSSLinkPage() |
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436 | |||
437 | /** |
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438 | * Comments interface for the front end. Includes the CommentAddForm and the composition |
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439 | * of the comments display. |
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440 | * |
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441 | * To customize the html see templates/CommentInterface.ss or extend this function with |
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442 | * your own extension. |
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443 | * |
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444 | * @todo Cleanup the passing of all this configuration based functionality |
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445 | * |
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446 | * @see docs/en/Extending |
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447 | */ |
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448 | public function CommentsForm() |
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483 | |||
484 | /** |
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485 | * Returns whether this extension instance is attached to a {@link SiteTree} object |
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486 | * |
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487 | * @return bool |
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488 | */ |
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489 | public function attachedToSiteTree() |
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495 | |||
496 | /** |
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497 | * Get the commenting option for this object. |
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498 | * |
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499 | * This can be overridden in any instance or extension to customise the |
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500 | * option available. |
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501 | * |
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502 | * @param string $key |
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503 | * |
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504 | * @return mixed Result if the setting is available, or null otherwise |
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505 | */ |
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506 | public function getCommentsOption($key) |
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522 | |||
523 | /** |
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524 | * @return array |
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525 | */ |
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526 | public function getCommentsOptions() |
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538 | |||
539 | /** |
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540 | * Add moderation functions to the current fieldlist |
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541 | * |
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542 | * @param FieldList $fields |
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543 | */ |
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544 | protected function updateModerationFields(FieldList $fields) |
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607 | |||
608 | public function updateCMSFields(FieldList $fields) |
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620 | } |
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621 |
This check marks private properties in classes that are never used. Those properties can be removed.