Theme 类，应用的主题，通过替换路径实现主题的应用，方法为获取根路径和根链接：yii2aseTheme.php
1 <?php 2 /** 3 * @link http://www.yiiframework.com/ 4 * @copyright Copyright (c) 2008 Yii Software LLC 5 * @license http://www.yiiframework.com/license/ 6 */ 7 8 namespace yiibase; 9 10 use Yii; 11 use yiihelpersFileHelper; 12 13 /** 14 * Theme represents an application theme. 15 * Theme 类，应用的主题 16 * When [[View]] renders a view file, it will check the [[View::theme|active theme]] 17 * to see if there is a themed version of the view file exists. If so, the themed version will be rendered instead. 18 * 视图对象[[View]]渲染视图文件的时候，会检查视图的主题是否存在，如果存在则渲染主题取代默认样式 19 * A theme is a directory consisting of view files which are meant to replace their non-themed counterparts. 20 * 21 * Theme uses [[pathMap]] to achieve the view file replacement: 22 * 23 * 1. It first looks for a key in [[pathMap]] that is a substring of the given view file path; 24 * 首先查找关键字，关键字是一个给定的视图路径的字符串 25 * 2. If such a key exists, the corresponding value will be used to replace the corresponding part 26 * in the view file path;关键字存在，则用对应值替换给定的视图文件路径中对应的部分 27 * 3. It will then check if the updated view file exists or not. If so, that file will be used 28 * to replace the original view file.检查替换后的路径对应的文件是否存在，存在就替换原文件 29 * 4. If Step 2 or 3 fails, the original view file will be used. 30 * 2和3失败的话，返回原来的路径 31 * For example, if [[pathMap]] is `['@app/views' => '@app/themes/basic']`, 32 * then the themed version for a view file `@app/views/site/index.php` will be 33 * `@app/themes/basic/site/index.php`. 34 * 35 * It is possible to map a single path to multiple paths. For example, 36 * 37 * ~~~ 38 * 'pathMap' => [ 39 * '@app/views' => [ 40 * '@app/themes/christmas', 41 * '@app/themes/basic', 42 * ], 43 * ] 44 * ~~~ 45 * 46 * In this case, the themed version could be either `@app/themes/christmas/site/index.php` or 47 * `@app/themes/basic/site/index.php`. The former has precedence over the latter if both files exist. 48 * 49 * To use a theme, you should configure the [[View::theme|theme]] property of the "view" application 50 * component like the following: 51 * 52 * ~~~ 53 * 'view' => [ 54 * 'theme' => [ 55 * 'basePath' => '@app/themes/basic', 56 * 'baseUrl' => '@web/themes/basic', 57 * ], 58 * ], 59 * ~~~ 60 * 61 * The above configuration specifies a theme located under the "themes/basic" directory of the Web folder 62 * that contains the entry script of the application. If your theme is designed to handle modules, 63 * you may configure the [[pathMap]] property like described above. 64 * 65 * @property string $basePath The root path of this theme. All resources of this theme are located under this 66 * directory. 67 * @property string $baseUrl The base URL (without ending slash) for this theme. All resources of this theme 68 * are considered to be under this base URL. This property is read-only. 69 * 70 * @author Qiang Xue <qiang.xue@gmail.com> 71 * @since 2.0 72 */ 73 class Theme extends Component 74 { 75 /** 76 * @var array the mapping between view directories and their corresponding themed versions. 77 * This property is used by [[applyTo()]] when a view is trying to apply the theme. 78 * Path aliases can be used when specifying directories. 79 * 路径映射属性 设置替换映射关系 80 * If this property is empty or not set, a mapping [[Application::basePath]] to [[basePath]] will be used. 81 */ 82 public $pathMap; 83 84 private $_baseUrl;//设置要访问资源的url 85 86 /** 87 * @return string the base URL (without ending slash) for this theme. All resources of this theme are considered 88 * to be under this base URL. 返回当前主题的基础链接，其他资源都在链接里 89 */ 90 public function getBaseUrl() 91 { 92 return $this->_baseUrl; 93 } 94 95 /** 96 * @param $url string the base URL or path alias for this theme. All resources of this theme are considered 97 * to be under this base URL. 设置基础链接 98 */ 99 public function setBaseUrl($url) 100 { 101 $this->_baseUrl = rtrim(Yii::getAlias($url), '/'); 102 } 103 104 private $_basePath;//根路径 105 106 /** 107 * @return string the root path of this theme. All resources of this theme are located under this directory. 108 * 得到当前主题的根路径 109 * @see pathMap 110 */ 111 public function getBasePath() 112 { 113 return $this->_basePath; 114 } 115 116 /** 117 * @param string $path the root path or path alias of this theme. All resources of this theme are located 118 * under this directory. 设置当前主题根路径 119 * @see pathMap 120 */ 121 public function setBasePath($path) 122 { 123 $this->_basePath = Yii::getAlias($path); 124 } 125 126 /** 127 * Converts a file to a themed file if possible. 将一个文件替换主题文件 128 * If there is no corresponding themed file, the original file will be returned. 129 * 没有相应的主题文件，返回原文件。 130 * @param string $path the file to be themed 131 * @return string the themed file, or the original file if the themed version is not available. 132 * @throws InvalidConfigException if [[basePath]] is not set 133 */ 134 public function applyTo($path) 135 { 136 $pathMap = $this->pathMap; //取得路径映射 137 if (empty($pathMap)) {//没有设置值 抛出异常 138 if (($basePath = $this->getBasePath()) === null) { 139 throw new InvalidConfigException('The "basePath" property must be set.'); 140 } 141 //设置值为[模块根路径=>主题根路径]的形式 142 $pathMap = [Yii::$app->getBasePath() => [$basePath]]; 143 } 144 145 $path = FileHelper::normalizePath($path);//对路径中的"/".""进行统一 146 147 foreach ($pathMap as $from => $tos) { 148 //映射数组中的来源 149 $from = FileHelper::normalizePath(Yii::getAlias($from)) . DIRECTORY_SEPARATOR; 150 if (strpos($path, $from) === 0) {//如果在$path中有可替换的旧值 151 $n = strlen($from); 152 foreach ((array) $tos as $to) { 153 $to = FileHelper::normalizePath(Yii::getAlias($to)) . DIRECTORY_SEPARATOR; 154 $file = $to . substr($path, $n);//把$path中的$from替换为$to 155 if (is_file($file)) { 156 return $file; //是文件直接返回 157 } 158 } 159 } 160 } 161 162 return $path; 163 } 164 165 /** 166 * Converts a relative URL into an absolute URL using [[baseUrl]]. 167 * 将一个相对URL转换为绝对URL 168 * @param string $url the relative URL to be converted.要转换的相对URL 169 * @return string the absolute URL 替换后的绝对URL 170 * @throws InvalidConfigException if [[baseUrl]] is not set 171 */ 172 public function getUrl($url) 173 { 174 if (($baseUrl = $this->getBaseUrl()) !== null) {//URL存在，进行转换 175 return $baseUrl . '/' . ltrim($url, '/'); 176 } else {//不存在抛出异常 177 throw new InvalidConfigException('The "baseUrl" property must be set.'); 178 } 179 } 180 181 /** 182 * Converts a relative file path into an absolute one using [[basePath]]. 183 * 通过相对路径生成绝对路径 184 * @param string $path the relative file path to be converted. 要转换的相对文件路径。 185 * @return string the absolute file path 转换后的绝对路径 186 * @throws InvalidConfigException if [[baseUrl]] is not set 187 */ 188 public function getPath($path) 189 { 190 if (($basePath = $this->getBasePath()) !== null) { 191 //返回拼接的路径 192 return $basePath . DIRECTORY_SEPARATOR . ltrim($path, '/\'); 193 } else { 194 throw new InvalidConfigException('The "basePath" property must be set.'); 195 } 196 } 197 }