yii source code analysis 4 - import registration of non-core classes, yii source code

yii源码分析4——非核心类的导入注册，yii源码

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在yii源码分析1中说到spl_autoload_register注册给定的函数作为 __autoload 的实现，在这里是autoload（）.

<span>public</span> <span>static</span> <span>function</span> autoload(<span>$className</span><span>) {
        </span><span>include</span> self::<span>$_coreClasses</span> [<span>$className</span><span>];
     }</span>

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实际上这个autoload()是没有考虑非核心文件的引入的。比如，在app文件夹经常会有自定义的一些重要文件夹，比如'application.utils.*（工具类），'application.filters.*'(过滤类)，'application.validators.*'（校验类）等。

在实际用的时候，是不用一个一个include的，直接new就可以了,yii已经帮我们做了include的工作。而这个工作就是在autoload()里面做的。

上面的代码很显然没有考虑非核心文件的引入，这是我的疏忽。

那yii是怎么帮我们引入非核心文件的？

这要从CApplication说起。

<span>abstract</span> <span>class</span> CApplication <span>extends</span><span> CModule {
    </span><span>public</span> <span>function</span> __construct(<span>$config</span> = <span>null</span><span>) {
        </span><span>if</span> (<span>is_string</span> ( <span>$config</span><span> ))
            </span><span>$config</span> = <span>require</span> (<span>$config</span><span>);
        Yii</span>::setApplication ( <span>$this</span> );<span>//</span><span>保存整个app实例</span>
        <span>if</span> (<span>isset</span> ( <span>$config</span> ['basePath'<span>] )) {
            </span><span>$this</span>->setBasePath ( <span>$config</span> ['basePath'<span>] );
            </span><span>unset</span> ( <span>$config</span> ['basePath'<span>] );
        } </span><span>else</span>
            <span>$this</span>->setBasePath ( 'protected'<span> );
        </span><span>//</span><span>设置别名,后面就可以用application表示basePath了</span>
        Yii::setPathOfAlias ( 'application', <span>$this</span>-><span>getBasePath () );
        </span><span>//</span><span>钩子，模块 预 初始化时执行，子类实现。不过这时，配置还没有写入框架</span>
        <span>$this</span>-><span>preinit ();
        </span><span>$this</span>-><span>registerCoreComponents ();
        </span><span>//</span><span>父类实现</span>
        <span>$this</span>->configure ( <span>$config</span><span> );
        </span><span>//</span><span>加载静态应用组件</span>
        <span>$this</span>-><span>preloadComponents ();
        </span><span>//</span><span>这才开始初始化模块</span>
        <span>$this</span>-><span>init ();
    }</span>

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注意到里面的$this->configure ( $config );，$config是传入的配置文件，是一个数组，非核心文件的定义就是在这里面，比如引入工具类文件夹

<?<span>php
</span><span>return</span> <span>array</span><span> (
    </span>'basePath' => <span>dirname</span> ( <span>__FILE__</span> ) . DIRECTORY_SEPARATOR . '..',
    'import' => <span>array</span><span> (
        </span>'application.utils.*'<span>
    )
    );
</span>?>

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然后在父类CModule

    <span>public</span> <span>function</span> configure(<span>$config</span><span>) {
        </span><span>if</span> (<span>is_array</span> ( <span>$config</span><span> )) {
            </span><span>foreach</span> ( <span>$config</span> <span>as</span> <span>$key</span> => <span>$value</span><span> )
                </span><span>$this</span>-><span>$key</span> = <span>$value</span><span>;
        }
    }</span>

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这里yii很"狡猾"，它在CModule的父类CComponent中重写了__set()

    <span>public</span> <span>function</span> __set(<span>$name</span>,<span>$value</span><span>)
    {
        </span><span>$setter</span>='set'.<span>$name</span><span>;
        </span><span>if</span>(<span>method_exists</span>(<span>$this</span>,<span>$setter</span><span>))
            </span><span>return</span> <span>$this</span>-><span>$setter</span>(<span>$value</span><span>);
        </span><span>else</span>....<span>
    }</span>

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可以看到，如果CModule中如果有设置yii指定参数（比如import）的方法，就会调用它，而我之前裁剪的时候，把CModule中的setImport（）删掉了。

另外可以看到basePath, params, modules, import, components 是yii保留的参数名。

    <span>public</span> <span>function</span> setImport(<span>$aliases</span><span>)
    {
        </span><span>foreach</span>(<span>$aliases</span> <span>as</span> <span>$alias</span><span>)
            Yii</span>::import(<span>$alias</span><span>);
    }</span>

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然后是YiiBase里面的import（）

    <span>public</span> <span>static</span> <span>function</span> import(<span>$alias</span>, <span>$forceInclude</span> = <span>false</span><span>) {
        </span><span>if</span> (<span>isset</span> ( self::<span>$_imports</span> [<span>$alias</span>] )) <span>//</span><span>是否已经存在路径</span>
            <span>return</span> self::<span>$_imports</span> [<span>$alias</span><span>];
        
        </span><span>if</span> (<span>class_exists</span> ( <span>$alias</span>, <span>false</span> ) || <span>interface_exists</span> ( <span>$alias</span>, <span>false</span> ))<span>//</span><span>类是否已经定义,针对如urlManager这样的已定义于$_coreClasses[]的类</span>
            <span>return</span> self::<span>$_imports</span> [<span>$alias</span>] = <span>$alias</span><span>;
        </span><span>if</span> ((<span>$pos</span> = <span>strrpos</span> ( <span>$alias</span>, '.' )) === <span>false</span>)         <span>//</span><span>直接是文件名</span>
<span>        {
            </span><span>//</span><span> try to autoload the class with an autoloader if $forceInclude is true</span>
            <span>if</span> (<span>$forceInclude</span> && (Yii::autoload ( <span>$alias</span>, <span>true</span> ) || <span>class_exists</span> ( <span>$alias</span>, <span>true</span><span> )))
                self</span>::<span>$_imports</span> [<span>$alias</span>] = <span>$alias</span><span>;
            </span><span>return</span> <span>$alias</span><span>;
        }
        
        </span><span>$className</span> = ( <span>string</span> ) <span>substr</span> ( <span>$alias</span>, <span>$pos</span> + 1<span> );
        </span><span>$isClass</span> = <span>$className</span> !== '*'<span>;
        </span><span>//</span><span>是否为路径+类名</span>
        <span>if</span> (<span>$isClass</span> && (<span>class_exists</span> ( <span>$className</span>, <span>false</span> ) || <span>interface_exists</span> ( <span>$className</span>, <span>false</span><span> )))
            </span><span>return</span> self::<span>$_imports</span> [<span>$alias</span>] = <span>$className</span><span>;
        </span><span>//</span><span>获取真实路径</span>
        <span>if</span> ((<span>$path</span> = self::getPathOfAlias ( <span>$alias</span> )) !== <span>false</span><span>) {
            </span><span>//</span><span>是否以*结尾，如application.utils.*</span>
            <span>if</span> (<span>$isClass</span><span>) {
                </span><span>if</span> (<span>$forceInclude</span><span>) {
                    </span><span>if</span> (<span>is_file</span> ( <span>$path</span> . '.php'<span> ))
                        </span><span>require</span> (<span>$path</span> . '.php'<span>);
                    </span><span>else</span>
                        <span>throw</span> <span>new</span> CException ( Yii::t ( 'yii', 'Alias "{alias}" is invalid. Make sure it points to an existing PHP file and the file is readable.', <span>array</span><span> (
                                </span>'{alias}' => <span>$alias</span><span> 
                        ) ) );
                    self</span>::<span>$_imports</span> [<span>$alias</span>] = <span>$className</span><span>;
                } </span><span>else</span><span>
                    self</span>::<span>$classMap</span> [<span>$className</span>] = <span>$path</span> . '.php'<span>;
                </span><span>return</span> <span>$className</span><span>;
            } </span><span>else</span>             <span>//</span><span> a directory</span>
<span>            {
                </span><span>if</span> (self::<span>$_includePaths</span> === <span>null</span><span>) {
                    self</span>::<span>$_includePaths</span> = <span>array_unique</span> ( <span>explode</span> ( PATH_SEPARATOR, <span>get_include_path</span><span> () ) );
                    </span><span>if</span> ((<span>$pos</span> = <span>array_search</span> ( '.', self::<span>$_includePaths</span>, <span>true</span> )) !== <span>false</span><span>)
                        </span><span>unset</span> ( self::<span>$_includePaths</span> [<span>$pos</span><span>] );
                }
                
                </span><span>array_unshift</span> ( self::<span>$_includePaths</span>, <span>$path</span><span> );
                
                </span><span>if</span> (self::<span>$enableIncludePath</span> && <span>set_include_path</span> ( '.' . PATH_SEPARATOR . <span>implode</span> ( PATH_SEPARATOR, self::<span>$_includePaths</span> ) ) === <span>false</span><span>)
                    self</span>::<span>$enableIncludePath</span> = <span>false</span><span>;
                </span><span>return</span> self::<span>$_imports</span> [<span>$alias</span>] = <span>$path</span><span>;
            }
        }
    }</span>

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一系列的判断，最后走到最后的else，将path写入到$_imports，这时仍然没有include.

include在autoload()

    <span>public</span> <span>static</span> <span>function</span> autoload(<span>$className</span><span>)
    {
        </span><span>//</span><span> use include so that the error PHP file may appear</span>
        <span>if</span>(<span>isset</span>(self::<span>$classMap</span>[<span>$className</span><span>]))
            </span><span>include</span>(self::<span>$classMap</span>[<span>$className</span><span>]);
        </span><span>elseif</span>(<span>isset</span>(self::<span>$_coreClasses</span>[<span>$className</span><span>]))
            </span><span>include</span>(self::<span>$_coreClasses</span>[<span>$className</span><span>]);
        </span><span>else</span><span>
        {
            </span><span>//</span><span> include class file relying on include_path</span>
            <span>if</span>(<span>strpos</span>(<span>$className</span>,'\\')===<span>false</span>)  <span>//</span><span> class without namespace</span>
<span>            {
                </span><span>if</span>(self::<span>$enableIncludePath</span>===<span>false</span><span>)
                {
                    </span><span>foreach</span>(self::<span>$_includePaths</span> <span>as</span> <span>$path</span><span>)
                    {
                        </span><span>$classFile</span>=<span>$path</span>.DIRECTORY_SEPARATOR.<span>$className</span>.'.php'<span>;
                        </span><span>if</span>(<span>is_file</span>(<span>$classFile</span><span>))
                        {
                            </span><span>include</span>(<span>$classFile</span><span>);
                            </span><span>break</span><span>;
                        }
                    }
                }
                </span><span>else</span>
                    <span>include</span>(<span>$className</span>.'.php'<span>);
            }
            </span><span>return</span> <span>class_exists</span>(<span>$className</span>,<span>false</span>) || <span>interface_exists</span>(<span>$className</span>,<span>false</span><span>);
        }
        </span><span>return</span> <span>true</span><span>;
    }</span>

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如果需要include的是非核心文件，那这里的$className只是一个alias,即文件名的前缀。

裁剪的yii http://files.cnblogs.com/TheViper/framework.zip

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