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 QueryBuilderEngine 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 QueryBuilderEngine, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
20 | class QueryBuilderEngine extends BaseEngine implements DataTableEngineContract |
||
21 | { |
||
22 | /** |
||
23 | * @param \Illuminate\Database\Query\Builder $builder |
||
24 | * @param \Yajra\Datatables\Request $request |
||
25 | */ |
||
26 | public function __construct(Builder $builder, Request $request) |
||
27 | { |
||
28 | $this->query = $builder; |
||
29 | $this->init($request, $builder); |
||
30 | } |
||
31 | |||
32 | /** |
||
33 | * Initialize attributes. |
||
34 | * |
||
35 | * @param \Yajra\Datatables\Request $request |
||
36 | * @param \Illuminate\Database\Query\Builder $builder |
||
37 | * @param string $type |
||
38 | */ |
||
39 | protected function init($request, $builder, $type = 'builder') |
||
|
|||
40 | { |
||
41 | $this->request = $request; |
||
42 | $this->query_type = $type; |
||
43 | $this->columns = $builder->columns; |
||
44 | $this->connection = $builder->getConnection(); |
||
45 | $this->prefix = $this->connection->getTablePrefix(); |
||
46 | $this->database = $this->connection->getDriverName(); |
||
47 | if ($this->isDebugging()) { |
||
48 | $this->connection->enableQueryLog(); |
||
49 | } |
||
50 | } |
||
51 | |||
52 | /** |
||
53 | * @inheritdoc |
||
54 | */ |
||
55 | public function filter(Closure $callback) |
||
56 | { |
||
57 | $this->overrideGlobalSearch($callback, $this->query); |
||
58 | |||
59 | return $this; |
||
60 | } |
||
61 | |||
62 | /** |
||
63 | * @inheritdoc |
||
64 | */ |
||
65 | public function make($mDataSupport = false, $orderFirst = false) |
||
69 | |||
70 | /** |
||
71 | * @inheritdoc |
||
72 | */ |
||
73 | public function totalCount() |
||
77 | |||
78 | /** |
||
79 | * Counts current query. |
||
80 | * |
||
81 | * @return int |
||
82 | */ |
||
83 | public function count() |
||
96 | |||
97 | /** |
||
98 | * @inheritdoc |
||
99 | */ |
||
100 | public function filtering() |
||
141 | |||
142 | /** |
||
143 | * Get eager loads keys if eloquent. |
||
144 | * |
||
145 | * @return array |
||
146 | */ |
||
147 | private function getEagerLoads() |
||
155 | |||
156 | /** |
||
157 | * Perform filter column on selected field. |
||
158 | * |
||
159 | * @param mixed $query |
||
160 | * @param string $method |
||
161 | * @param mixed $parameters |
||
162 | * @param string $column |
||
163 | * @param string $keyword |
||
164 | */ |
||
165 | protected function compileColumnQuery($query, $method, $parameters, $column, $keyword) |
||
185 | |||
186 | /** |
||
187 | * Build Query Builder Parameters. |
||
188 | * |
||
189 | * @return array |
||
190 | */ |
||
191 | protected function parameterize() |
||
200 | |||
201 | /** |
||
202 | * Add relation query on global search. |
||
203 | * |
||
204 | * @param mixed $query |
||
205 | * @param string $column |
||
206 | * @param string $keyword |
||
207 | */ |
||
208 | protected function compileRelationSearch($query, $relation, $column, $keyword) |
||
218 | |||
219 | /** |
||
220 | * Add a query on global search. |
||
221 | * |
||
222 | * @param mixed $query |
||
223 | * @param string $column |
||
224 | * @param string $keyword |
||
225 | */ |
||
226 | protected function compileGlobalSearch($query, $column, $keyword) |
||
237 | |||
238 | /** |
||
239 | * Wrap a column and cast in pgsql. |
||
240 | * |
||
241 | * @param string $column |
||
242 | * @return string |
||
243 | */ |
||
244 | public function castColumn($column) |
||
253 | |||
254 | /** |
||
255 | * @inheritdoc |
||
256 | */ |
||
257 | public function columnSearch() |
||
299 | |||
300 | /** |
||
301 | * Get proper keyword to use for search. |
||
302 | * |
||
303 | * @param int $i |
||
304 | * @return string |
||
305 | */ |
||
306 | private function getSearchKeyword($i) |
||
314 | |||
315 | /** |
||
316 | * @inheritdoc |
||
317 | */ |
||
318 | public function ordering() |
||
348 | |||
349 | /** |
||
350 | * Get order by column name. |
||
351 | * |
||
352 | * @param array $orderable |
||
353 | * @return string |
||
354 | */ |
||
355 | private function setupOrderColumn(array $orderable) |
||
367 | |||
368 | /** |
||
369 | * @inheritdoc |
||
370 | */ |
||
371 | public function paging() |
||
376 | |||
377 | /** |
||
378 | * Get results |
||
379 | * |
||
380 | * @return array|static[] |
||
381 | */ |
||
382 | public function results() |
||
386 | } |
||
387 |