Complex classes like QueryGenerator 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 QueryGenerator, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
16 | class QueryGenerator { |
||
17 | |||
18 | /* The term to search for */ |
||
19 | private $queryText = ''; |
||
20 | |||
21 | /* Fields to search for as an array of Name to weighting, otherwise null for all, ie not |
||
22 | a multi match query */ |
||
23 | private $fields = null; |
||
24 | |||
25 | /* Aggregations already selected in format array(key => value), e.g. array('ISO' => 400) */ |
||
26 | private $selectedFilters = null; |
||
27 | |||
28 | /* For an empty query, show results or not */ |
||
29 | private $showResultsForEmptyQuery = false; |
||
30 | |||
31 | /* Manipulator to be used for aggregations */ |
||
32 | private $manipulator = null; |
||
33 | |||
34 | /* The length of a page of results */ |
||
35 | private $pageLength = 10; |
||
36 | |||
37 | /* Where to start, normally a multiple of pageLength */ |
||
38 | private $start = 0; |
||
39 | |||
40 | /* Cache hit counter for test purposes */ |
||
41 | private static $cacheHitCtr = 0; |
||
42 | |||
43 | /** |
||
44 | * Comma separated list of SilverStripe ClassNames to search. Leave blank for all |
||
45 | * @var string |
||
46 | */ |
||
47 | private $classes = ''; |
||
48 | |||
49 | |||
50 | public function setQueryText($newQueryText) { |
||
51 | $this->queryText = $newQueryText; |
||
52 | } |
||
53 | |||
54 | |||
55 | public function setFields($newFields) { |
||
56 | $this->fields = $newFields; |
||
57 | } |
||
58 | |||
59 | |||
60 | public function setSelectedFilters($newSelectedFilters) { |
||
61 | $this->selectedFilters = $newSelectedFilters; |
||
62 | } |
||
63 | |||
64 | |||
65 | public function setShowResultsForEmptyQuery($newShowResultsForEmptyQuery) { |
||
66 | $this->showResultsForEmptyQuery = $newShowResultsForEmptyQuery; |
||
67 | } |
||
68 | |||
69 | |||
70 | public function getShowResultsForEmptyQuery() { |
||
71 | return $this->showResultsForEmptyQuery; |
||
72 | } |
||
73 | |||
74 | |||
75 | public function setPageLength($newPageLength) { |
||
76 | $this->pageLength = $newPageLength; |
||
77 | } |
||
78 | |||
79 | |||
80 | public function setStart($newStart) { |
||
81 | $this->start = $newStart; |
||
82 | } |
||
83 | |||
84 | |||
85 | /** |
||
86 | * Update the list of Classes to search, use SilverStripe ClassName comma separated |
||
87 | * @param string $newClasses comma separated list of SilverStripe ClassNames |
||
88 | */ |
||
89 | public function setClasses($newClasses) { |
||
90 | $this->classes = $newClasses; |
||
91 | } |
||
92 | |||
93 | |||
94 | |||
95 | /** |
||
96 | * Set the manipulator, mainly used for aggregation |
||
97 | * @param string $newManipulator manipulator used for aggregation, must implement ElasticaSearchHelper |
||
98 | */ |
||
99 | public function setQueryResultManipulator($newManipulator) { |
||
100 | $this->manipulator = $newManipulator; |
||
101 | } |
||
102 | |||
103 | |||
104 | /* |
||
105 | Accessor to cache hit counter, for testing purposes |
||
106 | */ |
||
107 | public static function getCacheHitCounter() { |
||
108 | return self::$cacheHitCtr; |
||
109 | } |
||
110 | |||
111 | |||
112 | public static function resetCacheHitCounter() { |
||
115 | |||
116 | |||
117 | /** |
||
118 | * From the input variables create a suitable query using Elastica. This is somewhat complex |
||
119 | * due to different formats with and without query text, with and without filters, with and |
||
120 | * without selected filters. Extracting this logic into a separate class makes testing much |
||
121 | * faster and can be used for testing new cases |
||
122 | * |
||
123 | * @return \Elastica\Query Query object suitable for searching using the Elastica library |
||
124 | */ |
||
125 | public function generateElasticaQuery() { |
||
126 | $queryTextExists = ($this->queryText != ''); |
||
127 | $isMultiMatch = ($this->fields != null); |
||
128 | |||
129 | if ($this->selectedFilters == null) { |
||
130 | $this->selectedFilters = array(); |
||
131 | } |
||
132 | |||
133 | $this->manipulatorInstance = null; |
||
134 | if ($this->manipulator) { |
||
135 | $this->manipulatorInstance = \Injector::inst()->create($this->manipulator); |
||
136 | $this->manipulatorInstance->queryGenerator = $this; |
||
137 | $this->manipulatorInstance->originalQueryString = $this->queryText; |
||
138 | } |
||
139 | |||
140 | //This is a query_string object |
||
141 | $textQuery = null; |
||
142 | |||
143 | if (!$isMultiMatch) { |
||
144 | $textQuery = $this->simpleTextQuery(); |
||
145 | } else { |
||
146 | $textQuery = $this->multiMatchQuery(); |
||
147 | } |
||
148 | |||
149 | $query = $this->addFilters($textQuery); |
||
|
|||
150 | |||
151 | //This ensures that the original query text is available to search helpers |
||
152 | $query->OriginalQueryText = $this->queryText; |
||
153 | |||
154 | //This needs to be query object of some form |
||
155 | $this->addAggregation($query); |
||
156 | |||
157 | |||
158 | // pagination |
||
159 | $query->setSize($this->pageLength); |
||
160 | $query->setFrom($this->start); |
||
161 | |||
162 | if ($this->manipulatorInstance && !$queryTextExists) { |
||
163 | $sort = $this->manipulatorInstance->getDefaultSort(); |
||
164 | $query->setSort($sort); |
||
165 | } |
||
166 | |||
167 | // Add suggestions in case required for poor spellings or typos |
||
168 | $suggest = new \Elastica\Suggest(); |
||
169 | $phrase = new \Elastica\Suggest\Phrase('query-phrase-suggestions', '_all'); |
||
170 | $phrase->setText($this->queryText)->setSize(4); |
||
171 | |||
172 | $highlightsCfg = \Config::inst()->get('Elastica', 'Highlights'); |
||
173 | $preTags = $highlightsCfg['PreTags']; |
||
174 | $postTags = $highlightsCfg['PostTags']; |
||
175 | |||
176 | $phrase->setHighlight($preTags, $postTags); |
||
177 | $suggest->addSuggestion($phrase); |
||
178 | $query->setSuggest($suggest); |
||
179 | return $query; |
||
180 | } |
||
181 | |||
182 | |||
183 | /** |
||
184 | * Generate a query for autocomplete |
||
185 | * @return \Elastica\Query Autocompletion query for use with Elastica library |
||
186 | */ |
||
187 | public function generateElasticaAutocompleteQuery() { |
||
188 | $field = array_keys($this->fields)[0]; |
||
189 | $data = array( |
||
190 | 'size' => 10, |
||
191 | 'query' => array( |
||
192 | 'match' => array( |
||
193 | $field.'.autocomplete' => array( |
||
194 | 'query' => $this->queryText, |
||
195 | 'operator' => 'and' |
||
196 | ) |
||
197 | ) |
||
198 | ) |
||
199 | ); |
||
200 | |||
201 | // The query clause can only have one entry, so a bit of mangling |
||
202 | if (!empty($this->selectedFilters)) { |
||
203 | $filtered = array(); |
||
204 | $filtered['query'] = $data['query']; |
||
205 | unset($data['query']); |
||
206 | $filtered['filter'] = array('term' => $this->selectedFilters); |
||
207 | $data['query'] = array('filtered' => $filtered); |
||
208 | } |
||
209 | |||
210 | /* |
||
211 | { |
||
212 | "filtered": { |
||
213 | "query": { "match": { "email": "business opportunity" }}, |
||
214 | "filter": { "term": { "folder": "inbox" }} |
||
215 | } |
||
216 | } |
||
217 | */ |
||
218 | $query = new Query($data); |
||
219 | return $query; |
||
220 | } |
||
221 | |||
222 | |||
223 | |||
224 | |||
225 | |||
226 | /** |
||
227 | * Using a query string object, return a suitable filtered or unfiltered query object |
||
228 | * @param Elastica\Query\QueryString $textQuery A query_string representing the current query |
||
229 | */ |
||
230 | private function addFilters($textQuery) { |
||
231 | if ($this->manipulator) { |
||
232 | $this->manipulatorInstance->updateFilters($this->selectedFilters); |
||
233 | } |
||
234 | |||
235 | $elFilters = array(); |
||
236 | $rangeFilterKeys = RangedAggregation::getTitles(); |
||
237 | |||
238 | foreach ($this->selectedFilters as $key => $value) { |
||
239 | if (!in_array($key, $rangeFilterKeys)) { |
||
240 | $filter = new Term(); |
||
241 | $filter->setTerm($key,$value); |
||
242 | $elFilters[] = $filter; |
||
243 | } else { |
||
244 | // get the selected range filter |
||
245 | $range = RangedAggregation::getByTitle($key); |
||
246 | $filter = $range->getFilter($value); |
||
247 | $elFilters[] = $filter; |
||
248 | } |
||
249 | } |
||
250 | |||
251 | |||
252 | // if not facets selected, pass through null |
||
253 | $queryFilter = null; |
||
254 | switch (count($this->selectedFilters)) { |
||
255 | case 0: |
||
256 | // filter already null |
||
257 | break; |
||
258 | case 1: |
||
259 | $queryFilter = $elFilters[0]; |
||
260 | break; |
||
261 | default: |
||
262 | $queryFilter = new BoolAnd(); |
||
263 | |||
264 | foreach ($elFilters as $filter) { |
||
265 | $queryFilter->addFilter($filter); |
||
266 | } |
||
267 | break; |
||
268 | } |
||
269 | |||
270 | // the Elastica query object |
||
271 | if ($queryFilter == null) { |
||
272 | $query = new Query($textQuery); |
||
273 | } else { |
||
274 | //MatchAll appears not be allowed inside a filtered query which is a bit of a pain. |
||
275 | if ($textQuery instanceof MatchAll) { |
||
276 | $textQuery = null; |
||
277 | } |
||
278 | |||
279 | $filtered = new Filtered( |
||
280 | $textQuery, |
||
281 | $queryFilter |
||
282 | ); |
||
283 | $query = new Query($filtered); |
||
284 | } |
||
285 | |||
286 | return $query; |
||
287 | } |
||
288 | |||
289 | |||
290 | private function addAggregation(&$query) { |
||
296 | |||
297 | |||
298 | /* |
||
299 | Simplest form of search, namely search for text string against all fields. In Curl terms: |
||
300 | |||
301 | curl -XGET 'http://localhost:9200/elastica_ss_module_test_en_us/_search?pretty' -d ' |
||
302 | { |
||
303 | "query": { |
||
304 | "query_string": { |
||
305 | "query": "Image" |
||
306 | } |
||
307 | } |
||
308 | } |
||
309 | ' |
||
310 | */ |
||
311 | private function simpleTextQuery() { |
||
325 | |||
326 | |||
327 | // USE MATCH_ALL, see https://www.elastic.co/guide/en/elasticsearch/reference/1.4/query-dsl-match-all-query.html |
||
328 | private function multiMatchQuery() { |
||
357 | |||
358 | |||
359 | |||
360 | /** |
||
361 | * Use the configuration from the Search settings held in the database to |
||
362 | * form the array of fields suitable for a multimatch query. Call this |
||
363 | * after having called setClasses |
||
364 | * |
||
365 | * @return array Array of fieldsname to weight |
||
366 | */ |
||
367 | public function convertWeightedFieldsForElastica($fields) { |
||
393 | |||
394 | |||
395 | |||
396 | /** |
||
397 | * Get a hash of name to Elasticserver mapping, e.g. 'Title' => 'string' |
||
398 | * Use SS_Cache to save on database hits, as this data only changes at build time |
||
399 | * @param string $classes CSV or array of ClassNames to search, or empty for |
||
400 | * all of SiteTree |
||
401 | * @return array Array hash of fieldname to Elasticsearch mapping |
||
402 | */ |
||
403 | public static function getSearchFieldsMappingForClasses($classes = null, $fieldsAllowed = null) { |
||
472 | |||
473 | |||
474 | public static function getCache() { |
||
478 | |||
479 | |||
480 | /** |
||
481 | * Convert either a CSV string or an array to a CSV single quoted string, suitable for use in |
||
482 | * an SQL IN clause |
||
483 | * @param string|array $csvOrArray A string separated by commas or an array |
||
484 | * @return string string or array as a CSV, but values quoted with single quotes |
||
485 | */ |
||
486 | public static function convertToQuotedCSV($csvOrArray) { |
||
505 | } |
||
506 |
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: