今天在這裏不過多介紹什麼是設計模式和爲什麼要使用它？可以參考漫談設計模式之組合模式。
一、什麼是抽象工廠設計模式？
一言以蔽之，抽象工廠就是用來創建功能相關的類，
二、在什麼場景下使用它？
顧名思義，在我們的業務當中會有一種場景，有一個查詢頁面，上面有很多很多的查詢條件，最終你會組合這些查詢條件查詢出實際想要的數據，請問你是怎麼做的？下面是我的設計，運用了單例、工廠和策略模式，一切面向接口編程。
三、設計思路
1、定義策略接口，定義一個format方法
2、按實際業務抽象出三種策略，1、模糊查詢，2、等於查詢，3、要經過特殊處理的查詢
3、定義一個抽象工廠，按需初始化三種策略對象
4、定義一個統一入口TutorConditionFormatter，創建工廠對象，工廠對象創建策略對象，策略對象處理數據，最後返回要求格式
5、業務當中直接調用TutorConditionFormatter
<?php
//------策略模式
/**
* 策略模式interface
* TutorConditionFormatterInterface
*/
namespace Logic\Tutor\ConditionFactoryFormatter;
interface TutorConditionFormatterInterface
{
public function format($aTutor);
}
<?php
/**
* 模糊查詢策略
* TutorConditionLikeFormatter
*/
namespace Logic\Tutor\ConditionFactoryFormatter;
class TutorConditionLikeFormatter implements TutorConditionFormatterInterface
{
public function format ($aParams)
{
$aFormatColumn = ['certifications','background','interview_time'];
$aParamKey = array_keys($aParams);
$aFormatKey = array_intersect($aFormatColumn,$aParamKey);
$aCondition = [];
if ($aFormatKey) {
foreach ($aFormatKey as $column) {
$item = $aParams["$column"];
if (!empty($item)) {
$item = array_unique($item);
sort($item);
$aCondition[] = sprintf("%s like '%s'",$column,'%'.implode(",", $item).'%');
}
}
}
return $aCondition;
}
}
<?php
/**
* 特殊查詢策略
* TutorConditionSpecialFormatter
*/
namespace Logic\Tutor\ConditionFactoryFormatter;
class TutorConditionSpecialFormatter implements TutorConditionFormatterInterface
{
const HAVE_RESUME = 1;//已上傳簡歷
const NONE_RESUME = 2;//未上傳簡歷
public function format ($aParams)
{
$aCondition = [];
if (isset($aParams['nationality']) && !empty($aParams['nationality'])) {
//對於others，查詢非United States和Canada的集合
if ($aParams['nationality'] > 2) {
$aCondition[] = sprintf('nationality >=3');
} else {
$aCondition[] = sprintf("nationality = %d",$aParams['nationality']);
}
}
if (isset($aParams['resume']) && !empty($aParams['resume'])) {
if (self::HAVE_RESUME == $aParams['resume']) {
$aCondition[] = sprintf("resume <> ''");
} elseif (self::NONE_RESUME == $aParams['resume']) {
$aCondition[] = sprintf("resume = ''");
}
}
if (isset($aParams['sourcing_team']) && !empty($aParams['sourcing_team'])) {
if (is_array($aParams['sourcing_team'])) {
$aCondition[] = sprintf("sourcing_team in('%s')",implode("','", $aParams['sourcing_team']));
} else {
$aCondition[] = sprintf("sourcing_team = %s",$aParams['sourcing_team']);
}
}
if (isset($aParams['demo_time_start']) && !empty($aParams['demo_time_start'])) {
$aCondition[] = sprintf("demo_result_date >= '%s 00:00:00'",$aParams['demo_time_start']);
}
if (isset($aParams['demo_time_end']) && !empty($aParams['demo_time_end'])) {
$aCondition[] = sprintf("demo_result_date <= '%s 23:59:59'",$aParams['demo_time_end']);
}
return $aCondition;
}
}
<?php
/**
* 相等查詢策略
* TutorConditionEqualFormatter
*/
namespace Logic\Tutor\ConditionFactoryFormatter;
class TutorConditionEqualFormatter implements TutorConditionFormatterInterface
{
const STATUS_FAILED = 'failed';
public function format ($aParams)
{
$aFormatColumn = ['mobile','country','state','email','time_zone','teaching_experience','zoom_id',
'interviewer','demo_status','sa_signed','skype_id','self_applied','source','educational_attainment'
];
$aParamKey = array_keys($aParams);
$aFormatKey = array_intersect($aFormatColumn,$aParamKey);
$aCondition = [];
if ($aFormatKey) {
foreach ($aFormatKey as $column) {
$item = $aParams["$column"];
if (!empty($item)) {
$aCondition[] = sprintf("%s = '%s'",$column,$item);
}
}
}
return $aCondition;
}
}
//------抽象工廠
<?php
/**
* 查詢條件格式化工廠
* TutorConditionFactory
*/
namespace Logic\Tutor\ConditionFactoryFormatter;
class TutorConditionFactory
{
private $_oFactory = null;
public static $_instance = null;
/**
* TutorConditionFactory constructor.
*/
private function __construct ()
{
if($this->_oFactory == null) {
$this->register();
}
}
/**
* @return TutorConditionFactory|null
*/
public static function getInstance()
{
if (self::$_instance == null) {
self::$_instance = new TutorConditionFactory();
}
return self::$_instance;
}
/**
* 註冊工廠類
* @return $this
*/
public function register()
{
$this->_oFactory['equal'] = __NAMESPACE__ . '\TutorConditionEqualFormatter';
$this->_oFactory['like'] = __NAMESPACE__ . '\TutorConditionLikeFormatter';
$this->_oFactory['special'] = __NAMESPACE__ . '\TutorConditionSpecialFormatter';
return $this;
}
/**
* 創建工廠類
* @param $type
* @return mixed
* @throws \Exception
*/
public function create($type)
{
if (!array_key_exists($type,$this->_oFactory)) {
throw new \Exception(sprintf("%s is not valid",$type));
}
$producer = $this->_oFactory["$type"];
return new $producer();
}
}
<?php
/**
* 格式化數據統一入口，完成兩件事
* 按要求生產策略對象
* 按策略對象格式化處理數據，最終返回所需的數據格式
*/
namespace Logic\Tutor;
use \Logic\Tutor\ConditionFactoryFormatter;
class TutorConditionFormatter
{
public function __construct ()
{
//定義需要處理的策略
$this->_aFormatter = ['equal','like','special'];
}
public function format($aParams)
{
$oFactory = ConditionFactoryFormatter\TutorConditionFactory::getInstance();
//刪除p和psize，與tutor無關
unset($aParams['p'],$aParams['psize']);
$aCondition[] = sprintf("training_type_id >=1");
if (empty($aParams)) {
return $aCondition;
}
//根據要求的策略處理數據，返回要求的數據
foreach ($this->_aFormatter as $formatter)
{
$oProducer = $oFactory->create($formatter);
$item = $oProducer->format($aParams);
$aCondition = array_merge($aCondition,$item);
}
unset($formatter,$item,$aParams);
return array_unique($aCondition);
}
}
//業務當中具體使用
<?php
//工廠模式格式化查詢條件
$oConditionFormatter = new TutorConditionFormatter();
/**
* $aSearch 是接受的請求參數
* $aCondition 是最終處理好的可供DbModel直接使用的查詢條件數據
*/
$aCondition = $oConditionFormatter->format($aSearch);