search
HomeBackend DevelopmentPHP Tutorialyii2 source code study notes (twenty), yii2 source code study notes_PHP tutorial

yii2 source code study notes (20), yii2 source code study notes

The Widget class is the base class of all components. yii2baseWidget.php

<span>  1</span> <?<span>php
</span><span>  2</span> <span>/*</span><span>*
</span><span>  3</span> <span> * @link </span><span>http://www.yiiframework.com/</span>
<span>  4</span> <span> * @copyright Copyright (c) 2008 Yii Software LLC
</span><span>  5</span> <span> * @license </span><span>http://www.yiiframework.com/license/</span>
<span>  6</span>  <span>*/</span>
<span>  7</span> 
<span>  8</span> <span>namespace</span> yii\<span>base</span><span>;
</span><span>  9</span> 
<span> 10</span> <span>use Yii;
</span><span> 11</span> <span>use ReflectionClass;
</span><span> 12</span> 
<span> 13</span> <span>/*</span><span>*
</span><span> 14</span> <span> * Widget is the base class for widgets.
</span><span> 15</span> <span> * Widget是所有小部件的基类
</span><span> 16</span> <span> * @property string $id ID of the widget. 小部件标识
</span><span> 17</span> <span> * @property \yii\web\View $view The view object that can be used to render views or view files. Note that the
</span><span> 18</span> <span> * type of this property differs in getter and setter. See [[getView()]] and [[setView()]] for details.
</span><span> 19</span> <span> * 用于渲染视图或视图文件的视图对象 在getter 和 setter中是不同的
</span><span> 20</span> <span> * @property string $viewPath The directory containing the view files for this widget. This property is
</span><span> 21</span> <span> * read-only. 包含此控件的视图文件目录
</span><span> 22</span> <span> *
</span><span> 23</span> <span> * @author Qiang Xue <qiang.xue@gmail.com>
</span><span> 24</span> <span> * @since 2.0
</span><span> 25</span>  <span>*/</span>
<span> 26</span> <span>class</span><span> Widget extends Component implements ViewContextInterface
</span><span> 27</span> <span>{
</span><span> 28</span>     <span>/*</span><span>*
</span><span> 29</span> <span>     * @var integer a counter used to generate [[id]] for widgets.
</span><span> 30</span> <span>     * @internal 用于生成widget ID的计数器
</span><span> 31</span>      <span>*/</span>
<span> 32</span>     <span>public</span> <span>static</span> $counter = <span>0</span><span>;
</span><span> 33</span>     <span>/*</span><span>*
</span><span> 34</span> <span>     * @var string the prefix to the automatically generated widget IDs.
</span><span> 35</span> <span>     * @see getId() 自动生成的前缀
</span><span> 36</span>      <span>*/</span>
<span> 37</span>     <span>public</span> <span>static</span> $autoIdPrefix = <span>'</span><span>w</span><span>'</span><span>;
</span><span> 38</span>     <span>/*</span><span>*
</span><span> 39</span> <span>     * @var Widget[] the widgets that are currently being rendered (not ended). This property
</span><span> 40</span> <span>     * is maintained by [[begin()]] and [[end()]] methods. 目前正在渲染的小部件
</span><span> 41</span> <span>     * @internal
</span><span> 42</span>      <span>*/</span>
<span> 43</span>     <span>public</span> <span>static</span> $stack =<span> [];
</span><span> 44</span> 
<span> 45</span> 
<span> 46</span>     <span>/*</span><span>*
</span><span> 47</span> <span>     * Begins a widget.  开始一个部件
</span><span> 48</span> <span>     * This method creates an instance of the calling class. It will apply the configuration
</span><span> 49</span> <span>     * to the created instance. A matching [[end()]] call should be called later.
</span><span> 50</span> <span>     * 将应用配置文件创建调用类的实例,与[end()]方法相对应
</span><span> 51</span> <span>     * @param array $config name-value pairs that will be used to initialize the object properties
</span><span> 52</span> <span>     * 用于初始化属性的参数
</span><span> 53</span> <span>     * @return static the newly created widget instance 静态新创建的部件实例
</span><span> 54</span>      <span>*/</span>
<span> 55</span>     <span>public</span> <span>static</span> function begin($config =<span> [])
</span><span> 56</span> <span>    {
</span><span> 57</span>         $config[<span>'</span><span>class</span><span>'</span>] = get_called_class();<span>//</span><span>后期静态绑定类的名称</span>
<span> 58</span>         <span>/*</span><span> @var $widget Widget </span><span>*/</span>
<span> 59</span>         $widget = Yii::createObject($config);<span>//</span><span>通过类名和传入的配置,实例化调用类</span>
<span> 60</span>         <span>static</span>::$stack[] = $widget;<span>//</span><span>将对象放入正在渲染的部件堆栈中</span>
<span> 61</span> 
<span> 62</span>         <span>return</span><span> $widget;
</span><span> 63</span> <span>    }
</span><span> 64</span> 
<span> 65</span>     <span>/*</span><span>*
</span><span> 66</span> <span>     * Ends a widget.   结束小部件
</span><span> 67</span> <span>     * Note that the rendering result of the widget is directly echoed out.渲染结果是直接呼应的
</span><span> 68</span> <span>     * @return static the widget instance that is ended. 静态结束的部件实例。
</span><span> 69</span> <span>     * @throws InvalidCallException if [[begin()]] and [[end()]] calls are not properly nested
</span><span> 70</span>      <span>*/</span>
<span> 71</span>     <span>public</span> <span>static</span><span> function end()
</span><span> 72</span> <span>    {
</span><span> 73</span>         <span>if</span> (!empty(<span>static</span>::$stack)) {<span>//</span><span>正在呈现的小部件堆栈中存在调用类实例</span>
<span> 74</span>             $widget = array_pop(<span>static</span>::$stack);<span>//</span><span>从堆栈中删除最后一个实例</span>
<span> 75</span>             <span>if</span> (get_class($widget) ===<span> get_called_class()) {
</span><span> 76</span>                 echo $widget->run(); <span>//</span><span>如果删除的实例类名和当前调用类名相同,输出小部件的内容</span>
<span> 77</span>                 <span>return</span><span> $widget;
</span><span> 78</span>             } <span>else</span><span> {
</span><span> 79</span>                 <span>throw</span> <span>new</span> InvalidCallException(<span>"</span><span>Expecting end() of </span><span>"</span> . get_class($widget) . <span>"</span><span>, found </span><span>"</span><span> . get_called_class());
</span><span> 80</span> <span>            }
</span><span> 81</span>         } <span>else</span><span> {
</span><span> 82</span>             <span>throw</span> <span>new</span> InvalidCallException(<span>"</span><span>Unexpected </span><span>"</span> . get_called_class() . <span>'</span><span>::end() call. A matching begin() is not found.</span><span>'</span><span>);
</span><span> 83</span> <span>        }
</span><span> 84</span> <span>    }
</span><span> 85</span> 
<span> 86</span>     <span>/*</span><span>*
</span><span> 87</span> <span>     * Creates a widget instance and runs it.   创建一个部件实例,并运行
</span><span> 88</span> <span>     * The widget rendering result is returned by this method. 返回部件渲染的结果。
</span><span> 89</span> <span>     * @param array $config name-value pairs that will be used to initialize the object properties
</span><span> 90</span> <span>     * 用于初始化对象属性的参数
</span><span> 91</span> <span>     * @return string the rendering result of the widget. 控件的渲染结果。
</span><span> 92</span>      <span>*/</span>
<span> 93</span>     <span>public</span> <span>static</span> function widget($config =<span> [])
</span><span> 94</span> <span>    {
</span><span> 95</span>         ob_start(); <span>//</span><span>打开输出缓冲区</span>
<span> 96</span>         ob_implicit_flush(<span>false</span>);<span>//</span><span>关闭绝对刷新</span>
<span> 97</span>         <span>/*</span><span> @var $widget Widget </span><span>*/</span>
<span> 98</span>         $config[<span>'</span><span>class</span><span>'</span>] = get_called_class(); <span>//</span><span>获取调用类的类名</span>
<span> 99</span>         $widget = Yii::createObject($config);   <span>//</span><span>实例化类</span>
<span>100</span>         $<span>out</span> = $widget->run();<span>//</span><span>运行部件</span>
<span>101</span> 
<span>102</span>         <span>return</span> ob_get_clean() . $<span>out</span>; <span>//</span><span>返回内部缓冲区的内容,关闭缓冲区</span>
<span>103</span> <span>    }
</span><span>104</span> 
<span>105</span>     <span>private</span><span> $_id;
</span><span>106</span> 
<span>107</span>     <span>/*</span><span>*
</span><span>108</span> <span>     * Returns the ID of the widget. 返回插件的标识
</span><span>109</span> <span>     * @param boolean $autoGenerate whether to generate an ID if it is not set previously
</span><span>110</span> <span>     * 是否生成一个唯一标识,如果没有设置
</span><span>111</span> <span>     * @return string ID of the widget. 部件唯一标识
</span><span>112</span>      <span>*/</span>
<span>113</span>     <span>public</span> function getId($autoGenerate = <span>true</span><span>)
</span><span>114</span> <span>    {
</span><span>115</span>         <span>if</span> ($autoGenerate && $<span>this</span>->_id === <span>null</span><span>) {
</span><span>116</span>             <span>//</span><span>如果标识为空,并且设置为允许自动生成标识,自动生成</span>
<span>117</span>             $<span>this</span>->_id = <span>static</span>::$autoIdPrefix . <span>static</span>::$counter++<span>;
</span><span>118</span> <span>        }
</span><span>119</span> 
<span>120</span>         <span>return</span> $<span>this</span>-><span>_id;
</span><span>121</span> <span>    }
</span><span>122</span> 
<span>123</span>     <span>/*</span><span>*
</span><span>124</span> <span>     * Sets the ID of the widget. 设置小部件标识
</span><span>125</span> <span>     * @param string $value id of the widget. 部件的标识。
</span><span>126</span>      <span>*/</span>
<span>127</span>     <span>public</span><span> function setId($value)
</span><span>128</span> <span>    {
</span><span>129</span>         $<span>this</span>->_id =<span> $value;
</span><span>130</span> <span>    }
</span><span>131</span> 
<span>132</span>     <span>private</span><span> $_view;
</span><span>133</span> 
<span>134</span>     <span>/*</span><span>*
</span><span>135</span> <span>     * Returns the view object that can be used to render views or view files.返回视图对象
</span><span>136</span> <span>     * The [[render()]] and [[renderFile()]] methods will use
</span><span>137</span> <span>     * this view object to implement the actual view rendering.
</span><span>138</span> <span>     * [render()]和[renderFile()]方法用视图对象实现实际的视图显示。
</span><span>139</span> <span>     * If not set, it will default to the "view" application component.
</span><span>140</span> <span>     * @return \yii\web\View the view object that can be used to render views or view files.
</span><span>141</span>      <span>*/</span>
<span>142</span>     <span>public</span><span> function getView()
</span><span>143</span> <span>    {
</span><span>144</span>         <span>if</span> ($<span>this</span>->_view === <span>null</span><span>) {
</span><span>145</span>             $<span>this</span>->_view = Yii::$app->getView();<span>//</span><span>如果视图对象为空,调用getView()取得视图对象实例</span>
<span>146</span> <span>        }
</span><span>147</span> 
<span>148</span>         <span>return</span> $<span>this</span>-><span>_view;
</span><span>149</span> <span>    }
</span><span>150</span> 
<span>151</span>     <span>/*</span><span>*
</span><span>152</span> <span>     * Sets the view object to be used by this widget. 设置当前部件调用的视图对象实例
</span><span>153</span> <span>     * @param View $view the view object that can be used to render views or view files.
</span><span>154</span>      <span>*/</span>
<span>155</span>     <span>public</span><span> function setView($view)
</span><span>156</span> <span>    {
</span><span>157</span>         $<span>this</span>->_view = $view;<span>//</span><span>要用的视图对象</span>
<span>158</span> <span>    }
</span><span>159</span> 
<span>160</span>     <span>/*</span><span>*
</span><span>161</span> <span>     * Executes the widget. 执行部件
</span><span>162</span> <span>     * @return string the result of widget execution to be outputted.
</span><span>163</span> <span>     * 控件执行的结果输出。
</span><span>164</span>      <span>*/</span>
<span>165</span>     <span>public</span><span> function run()
</span><span>166</span> <span>    {
</span><span>167</span> <span>    }
</span><span>168</span> 
<span>169</span>     <span>/*</span><span>*
</span><span>170</span> <span>     * Renders a view.
</span><span>171</span> <span>     * The view to be rendered can be specified in one of the following formats:
</span><span>172</span> <span>     * 渲染一个视图   实际调用View类中的同名方法 渲染的视图可以用下列方式指定路径
</span><span>173</span> <span>     * - path alias (e.g. "@app/views/site/index");
</span><span>174</span> <span>     * - absolute path within application (e.g. "//site/index"): the view name starts with double slashes.
</span><span>175</span> <span>     *   The actual view file will be looked for under the [[Application::viewPath|view path]] of the application.
</span><span>176</span> <span>     * - absolute path within module (e.g. "/site/index"): the view name starts with a single slash.
</span><span>177</span> <span>     *   The actual view file will be looked for under the [[Module::viewPath|view path]] of the currently
</span><span>178</span> <span>     *   active module.
</span><span>179</span> <span>     * - relative path (e.g. "index"): the actual view file will be looked for under [[viewPath]].
</span><span>180</span> <span>     *
</span><span>181</span> <span>     * If the view name does not contain a file extension, it will use the default one `.php`.
</span><span>182</span> <span>     *
</span><span>183</span> <span>     * @param string $view the view name.   视图名
</span><span>184</span> <span>     * @param array $params the parameters (name-value pairs) that should be made available in the view.
</span><span>185</span> <span>     * 在视图中可用的参数
</span><span>186</span> <span>     * @return string the rendering result. 渲染结果
</span><span>187</span> <span>     * @throws InvalidParamException if the view file does not exist.
</span><span>188</span>      <span>*/</span>
<span>189</span>     <span>public</span> function render($view, $<span>params</span> =<span> [])
</span><span>190</span> <span>    {
</span><span>191</span>         <span>//</span><span>调用view类中的render渲染指定的视图</span>
<span>192</span>         <span>return</span> $<span>this</span>->getView()->render($view, $<span>params</span>, $<span>this</span><span>);
</span><span>193</span> <span>    }
</span><span>194</span> 
<span>195</span>     <span>/*</span><span>*
</span><span>196</span> <span>     * Renders a view file. 渲染一个视图文件 同上
</span><span>197</span> <span>     * @param string $file the view file to be rendered. This can be either a file path or a path alias.
</span><span>198</span> <span>     * @param array $params the parameters (name-value pairs) that should be made available in the view.
</span><span>199</span> <span>     * @return string the rendering result.
</span><span>200</span> <span>     * @throws InvalidParamException if the view file does not exist.
</span><span>201</span>      <span>*/</span>
<span>202</span>     <span>public</span> function renderFile($file, $<span>params</span> =<span> [])
</span><span>203</span> <span>    {
</span><span>204</span>         <span>return</span> $<span>this</span>->getView()->renderFile($file, $<span>params</span>, $<span>this</span><span>);
</span><span>205</span> <span>    }
</span><span>206</span> 
<span>207</span>     <span>/*</span><span>*
</span><span>208</span> <span>     * Returns the directory containing the view files for this widget. 返回视图文件路径
</span><span>209</span> <span>     * The default implementation returns the 'views' subdirectory under the directory containing the widget class file.
</span><span>210</span> <span>     * @return string the directory containing the view files for this widget.
</span><span>211</span>      <span>*/</span>
<span>212</span>     <span>public</span><span> function getViewPath()
</span><span>213</span> <span>    {
</span><span>214</span>         $<span>class</span> = <span>new</span> ReflectionClass($<span>this</span><span>);
</span><span>215</span>         <span>//</span><span>取得部件类文件的目录,拼接为视图目录</span>
<span>216</span>         <span>return</span> dirname($<span>class</span>->getFileName()) . DIRECTORY_SEPARATOR . <span>'</span><span>views</span><span>'</span><span>;
</span><span>217</span> <span>    }
</span><span>218</span> }

www.bkjia.comtruehttp: //www.bkjia.com/PHPjc/1137258.htmlTechArticleyii2 source code study notes (20), yii2 source code study notes The Widget class is the base class of all components. yii2baseWidget.php 1 ? php 2 /* * 3 * @link http://www.yiiframework.com/ 4 * @copyri...
Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
How can you check if a PHP session has already started?How can you check if a PHP session has already started?Apr 30, 2025 am 12:20 AM

In PHP, you can use session_status() or session_id() to check whether the session has started. 1) Use the session_status() function. If PHP_SESSION_ACTIVE is returned, the session has been started. 2) Use the session_id() function, if a non-empty string is returned, the session has been started. Both methods can effectively check the session state, and choosing which method to use depends on the PHP version and personal preferences.

Describe a scenario where using sessions is essential in a web application.Describe a scenario where using sessions is essential in a web application.Apr 30, 2025 am 12:16 AM

Sessionsarevitalinwebapplications,especiallyfore-commerceplatforms.Theymaintainuserdataacrossrequests,crucialforshoppingcarts,authentication,andpersonalization.InFlask,sessionscanbeimplementedusingsimplecodetomanageuserloginsanddatapersistence.

How can you manage concurrent session access in PHP?How can you manage concurrent session access in PHP?Apr 30, 2025 am 12:11 AM

Managing concurrent session access in PHP can be done by the following methods: 1. Use the database to store session data, 2. Use Redis or Memcached, 3. Implement a session locking strategy. These methods help ensure data consistency and improve concurrency performance.

What are the limitations of using PHP sessions?What are the limitations of using PHP sessions?Apr 30, 2025 am 12:04 AM

PHPsessionshaveseverallimitations:1)Storageconstraintscanleadtoperformanceissues;2)Securityvulnerabilitieslikesessionfixationattacksexist;3)Scalabilityischallengingduetoserver-specificstorage;4)Sessionexpirationmanagementcanbeproblematic;5)Datapersis

Explain how load balancing affects session management and how to address it.Explain how load balancing affects session management and how to address it.Apr 29, 2025 am 12:42 AM

Load balancing affects session management, but can be resolved with session replication, session stickiness, and centralized session storage. 1. Session Replication Copy session data between servers. 2. Session stickiness directs user requests to the same server. 3. Centralized session storage uses independent servers such as Redis to store session data to ensure data sharing.

Explain the concept of session locking.Explain the concept of session locking.Apr 29, 2025 am 12:39 AM

Sessionlockingisatechniqueusedtoensureauser'ssessionremainsexclusivetooneuseratatime.Itiscrucialforpreventingdatacorruptionandsecuritybreachesinmulti-userapplications.Sessionlockingisimplementedusingserver-sidelockingmechanisms,suchasReentrantLockinJ

Are there any alternatives to PHP sessions?Are there any alternatives to PHP sessions?Apr 29, 2025 am 12:36 AM

Alternatives to PHP sessions include Cookies, Token-based Authentication, Database-based Sessions, and Redis/Memcached. 1.Cookies manage sessions by storing data on the client, which is simple but low in security. 2.Token-based Authentication uses tokens to verify users, which is highly secure but requires additional logic. 3.Database-basedSessions stores data in the database, which has good scalability but may affect performance. 4. Redis/Memcached uses distributed cache to improve performance and scalability, but requires additional matching

Define the term 'session hijacking' in the context of PHP.Define the term 'session hijacking' in the context of PHP.Apr 29, 2025 am 12:33 AM

Sessionhijacking refers to an attacker impersonating a user by obtaining the user's sessionID. Prevention methods include: 1) encrypting communication using HTTPS; 2) verifying the source of the sessionID; 3) using a secure sessionID generation algorithm; 4) regularly updating the sessionID.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Atom editor mac version download

Atom editor mac version download

The most popular open source editor

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

SublimeText3 English version

SublimeText3 English version

Recommended: Win version, supports code prompts!

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor