Theme 类，即一个应用的主题，主要通过替换路径实现主题的应用，里边的方法为获取根路径和根链接，以及应用主题的方法：
1 namespace yii\base;
2
3 use Yii;
4 use yii\helpers\FileHelper;
5
6 /**
7 * Theme represents an application theme.
8 * Theme 类，即一个应用的主题
9 *
10 * When [[View]] renders a view file, it will check the [[View::theme|active theme]]
11 * to see if there is a themed version of the view file exists. If so, the themed version will be rendered instead.
12 * 视图对象[[View]]渲染视图文件的时候，会检查视图的主题[[View::theme|active theme]]是否存在，如果存在则渲染主题取代默认样式
13 *
14 * A theme is a directory consisting of view files which are meant to replace their non-themed counterparts.
15 *
16 * Theme uses [[pathMap]] to achieve the view file replacement:
17 * Theme 通过[[pathMap]]来实现视图文件替换：
18 *
19 * 1. It first looks for a key in [[pathMap]] that is a substring of the given view file path;
20 * 首先在[[pathMap]] 中查找关键字，该关键字是一个给定的视图路径的子字符串
21 * 2. If such a key exists, the corresponding value will be used to replace the corresponding part
22 * in the view file path;
23 * 如果该关键字存在，则用对应得值替换给定的视图文件路径中对应的部分
24 * 3. It will then check if the updated view file exists or not. If so, that file will be used
25 * to replace the original view file.
26 * 然后检查替换后的路径对应的文件是否存在，如果存在就替换原来的文件
27 * 4. If Step 2 or 3 fails, the original view file will be used.
28 * 如果2和3失败的话，就返回原来的路径
29 *
30 * For example, if [[pathMap]] is `[‘@app/views‘ => ‘@app/themes/basic‘]`,
31 * then the themed version for a view file `@app/views/site/index.php` will be
32 * `@app/themes/basic/site/index.php`.
33 *
34 * It is possible to map a single path to multiple paths. For example,
35 *
36 * ```php
37 * ‘pathMap‘ => [
38 * ‘@app/views‘ => [
39 * ‘@app/themes/christmas‘,
40 * ‘@app/themes/basic‘,
41 * ],
42 * ]
43 * ```
44 *
45 * In this case, the themed version could be either `@app/themes/christmas/site/index.php` or
46 * `@app/themes/basic/site/index.php`. The former has precedence over the latter if both files exist.
47 * 主题的对应关系可以是一个视图文件对应多个主题文件
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 * ```php
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.
69 *
70 * @author Qiang Xue <[email protected]>
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 * If this property is empty or not set, a mapping [[Application::basePath]] to [[basePath]] will be used.
80 * 路径映射属性--用来设置替换映射关系的
81 */
82 public $pathMap;
83 /**
84 * @var 设置要访问的资源的url，没有结尾的斜线(without ending slash)
85 */
86 private $_baseUrl;
87
88
89 /**
90 * @return string the base URL (without ending slash) for this theme. All resources of this theme are considered
91 * to be under this base URL.
92 * @return string 返回值为当前主题的基础链接，即访问链接，其他的资源都在该链接下
93 */
94 public function getBaseUrl()
95 {
96 return $this->_baseUrl;
97 }
98
99 /**
100 * @param string $url the base URL or path alias for this theme. All resources of this theme are considered
101 * to be under this base URL.
102 * 设置基础访问链接
103 */
104 public function setBaseUrl($url)
105 {
106 $this->_baseUrl = rtrim(Yii::getAlias($url), ‘/‘);
107 }
108 /**
109 * @var array 当前主题的根路径，该主题的资源都在该目录下
110 */
111 private $_basePath;
112
113 /**
114 * @return string the root path of this theme. All resources of this theme are located under this directory.
115 * @return string 返回当前主题的根路径，该主题的资源都在该目录下
116 * @see pathMap
117 */
118 public function getBasePath()
119 {
120 return $this->_basePath;
121 }
122
123 /**
124 * @param string $path the root path or path alias of this theme. All resources of this theme are located
125 * under this directory.
126 * 设置当前主题的根路径
127 * @see pathMap
128 */
129 public function setBasePath($path)
130 {
131 $this->_basePath = Yii::getAlias($path);
132 }
133
134 /**
135 * Converts a file to a themed file if possible.
136 * 将一个文件替换为允许替换的主题文件---主题的应用原理
137 * If there is no corresponding themed file, the original file will be returned.
138 * 如果没有对应的主题文件，将返回源文件
139 * @param string $path the file to be themed
140 * @return string the themed file, or the original file if the themed version is not available.
141 * @throws InvalidConfigException if [[basePath]] is not set
142 */
143 public function applyTo($path)
144 {
145 $pathMap = $this->pathMap;//取得路径映射[[pathMap]]的值
146 if (empty($pathMap)) {//如果[[pathMap]]没有设置值，则取当前主题的根路径，否则抛出异常
147 if (($basePath = $this->getBasePath()) === null) {
148 throw new InvalidConfigException(‘The "basePath" property must be set.‘);
149 }
150 $pathMap = [Yii::$app->getBasePath() => [$basePath]];//设置$pathMap的值为[模块根路径=>主题根路径]的形式
151 }
152 //对路径中的"/"、“\”进行统一替换
153 $path = FileHelper::normalizePath($path);
154
155 foreach ($pathMap as $from => $tos) {
156 //映射数组中的来源（旧值）
157 $from = FileHelper::normalizePath(Yii::getAlias($from)) . DIRECTORY_SEPARATOR;
158 //如果在$path中有可替换的旧值
159 if (strpos($path, $from) === 0) {
160 $n = strlen($from);
161 //对目标值循环
162 foreach ((array) $tos as $to) {
163 $to = FileHelper::normalizePath(Yii::getAlias($to)) . DIRECTORY_SEPARATOR;
164 //把$path中的$from替换为$to
165 $file = $to . substr($path, $n);
166 //如果是文件，直接返回
167 if (is_file($file)) {
168 return $file;
169 }
170 }
171 }
172 }
173
174 return $path;
175 }
176
177 /**
178 * Converts a relative URL into an absolute URL using [[baseUrl]].
179 * 将一个相对URL替换为绝对URL
180 * @param string $url the relative URL to be converted.
181 * @return string the absolute URL
182 * @throws InvalidConfigException if [[baseUrl]] is not set
183 */
184 public function getUrl($url)
185 {
186 if (($baseUrl = $this->getBaseUrl()) !== null) {
187 return $baseUrl . ‘/‘ . ltrim($url, ‘/‘);//通过取得[[baseUrl]]的值拼接出当前主题的绝对URL
188 } else {
189 throw new InvalidConfigException(‘The "baseUrl" property must be set.‘);
190 }
191 }
192
193 /**
194 * Converts a relative file path into an absolute one using [[basePath]].
195 * 通过相对路径生成绝对路径
196 * @param string $path the relative file path to be converted.
197 * @return string the absolute file path
198 * @throws InvalidConfigException if [[basePath]] is not set
199 */
200 public function getPath($path)
201 {
202 if (($basePath = $this->getBasePath()) !== null) {
203 return $basePath . DIRECTORY_SEPARATOR . ltrim($path, ‘/\\‘);//通过取得[[basePath]]的值拼接出当前主题的绝对路径
204 } else {
205 throw new InvalidConfigException(‘The "basePath" property must be set.‘);
206 }
207 }
208 }
时间： 2024-10-12 17:10:56