Detailed explanation of classic PHP multi-function file upload class examples

File upload is a common function in project development, but the process of file upload is relatively cumbersome. As long as there is a file upload, these complex codes need to be written. In order to reduce the difficulty of writing functions in each development and to save development time, we usually encapsulate these repeatedly used pieces of code into a class. Help developers in future development to implement complex file upload functions by writing a few simple codes. For readers with weak foundation, as long as they know how to use this class, those who like challenges can try to understand it and develop their own File Upload Class.

1. Requirements Analysis

If you want to customize the file upload class, it can complete the following functions even if it is very easy to use:
　①Support single file upload.
　②Support multiple file uploads.
　③You can specify the storage location of the uploaded file yourself, you can set the size and type allowed for the uploaded file, you can rename the uploaded file by the system, and you can also set the original name of the uploaded file to be retained.
　(Note: It is required that single file upload and multiple file upload must use the same operation method, and some settings for upload must also use the same method).

2. Programming

According to the requirements of the program, we can declare 4 visible member attributes for the file upload class, so that users can You can also set some behaviors. The required member attributes are as shown in the following table:

In order to prevent the attribute values ​​from being assigned some illegal values, these member attributes need to be encapsulated and cannot be accessed outside the object. Then assign values ​​to the above four member attributes through the set() method declared in the class. The set() method has two parameters. The first parameter is the name of the member attribute (not case-sensitive), and the second parameter is the value corresponding to the attribute in the previous parameter. After the set() method is called, the object ($this) is returned. Therefore, in addition to assigning values ​​to each attribute individually, you can also perform consecutive operations to assign values ​​to multiple attributes together. In this example, in addition to the set() method, the most important thing is to implement the function of uploading files, so the system mainly provides the following public methods to implement file upload operations, as shown in the following table:

In order to prevent the attribute values ​​from being assigned some illegal values, these member attributes need to be encapsulated and cannot be accessed outside the object, and then the above four member attributes can be assigned values ​​through the set() method declared in the class. The set() method has two parameters. The first parameter is the name of the member attribute (not case-sensitive), and the second parameter is the value corresponding to the attribute in the previous parameter. After the set() method is called, the object ($this) is returned. Therefore, in addition to assigning values ​​to each attribute individually, you can also perform consecutive operations to assign values ​​to multiple attributes together. In this example, in addition to the set() method, the most important thing is to implement the function of uploading files, so the system mainly provides the following public methods to implement file upload operations, as shown in the following table:

<?php
  /** 
    file: fileupload.class.php 文件上传类FileUpload
    本类的实例对象用于处理上传文件，可以上传一个文件，也可同时处理多个文件上传
  */
  class FileUpload { 
    private $path = "./uploads";          //上传文件保存的路径
    private $allowtype = array(&#39;jpg&#39;,&#39;gif&#39;,&#39;png&#39;); //设置限制上传文件的类型
    private $maxsize = 1000000;           //限制文件上传大小（字节）
    private $israndname = true;           //设置是否随机重命名文件， false不随机
 
    private $originName;              //源文件名
    private $tmpFileName;              //临时文件名
    private $fileType;               //文件类型(文件后缀)
    private $fileSize;               //文件大小
    private $newFileName;              //新文件名
    private $errorNum = 0;             //错误号
    private $errorMess="";             //错误报告消息
 
    /**
     * 用于设置成员属性（$path, $allowtype,$maxsize, $israndname）
     * 可以通过连贯操作一次设置多个属性值
     *@param  string $key  成员属性名(不区分大小写)
     *@param  mixed  $val  为成员属性设置的值
     *@return  object     返回自己对象$this，可以用于连贯操作
     */
    function set($key, $val){
      $key = strtolower($key); 
      if( array_key_exists( $key, get_class_vars(get_class($this) ) ) ){
        $this->setOption($key, $val);
      }
      return $this;
    }
 
    /**
     * 调用该方法上传文件
     * @param  string $fileFile  上传文件的表单名称 
     * @return bool        如果上传成功返回数true 
     */
 
    function upload($fileField) {
      $return = true;
      /* 检查文件路径是滞合法 */
      if( !$this->checkFilePath() ) {       
        $this->errorMess = $this->getError();
        return false;
      }
      /* 将文件上传的信息取出赋给变量 */
      $name = $_FILES[$fileField][&#39;name&#39;];
      $tmp_name = $_FILES[$fileField][&#39;tmp_name&#39;];
      $size = $_FILES[$fileField][&#39;size&#39;];
      $error = $_FILES[$fileField][&#39;error&#39;];
 
      /* 如果是多个文件上传则$file["name"]会是一个数组 */
      if(is_Array($name)){    
        $errors=array();
        /*多个文件上传则循环处理 ， 这个循环只有检查上传文件的作用，并没有真正上传 */
        for($i = 0; $i < count($name); $i++){ 
          /*设置文件信息 */
          if($this->setFiles($name[$i],$tmp_name[$i],$size[$i],$error[$i] )) {
            if(!$this->checkFileSize() || !$this->checkFileType()){
              $errors[] = $this->getError();
              $return=false; 
            }
          }else{
            $errors[] = $this->getError();
            $return=false;
          }
          /* 如果有问题，则重新初使化属性 */
          if(!$return)          
            $this->setFiles();
        }
 
        if($return){
          /* 存放所有上传后文件名的变量数组 */
          $fileNames = array();      
          /* 如果上传的多个文件都是合法的，则通过销魂循环向服务器上传文件 */
          for($i = 0; $i < count($name); $i++){ 
            if($this->setFiles($name[$i], $tmp_name[$i], $size[$i], $error[$i] )) {
              $this->setNewFileName(); 
              if(!$this->copyFile()){
                $errors[] = $this->getError();
                $return = false;
              }
              $fileNames[] = $this->newFileName;  
            }          
          }
          $this->newFileName = $fileNames;
        }
        $this->errorMess = $errors;
        return $return;
      /*上传单个文件处理方法*/
      } else {
        /* 设置文件信息 */
        if($this->setFiles($name,$tmp_name,$size,$error)) {
          /* 上传之前先检查一下大小和类型 */
          if($this->checkFileSize() && $this->checkFileType()){ 
            /* 为上传文件设置新文件名 */
            $this->setNewFileName(); 
            /* 上传文件  返回0为成功， 小于0都为错误 */
            if($this->copyFile()){ 
              return true;
            }else{
              $return=false;
            }
          }else{
            $return=false;
          }
        } else {
          $return=false; 
        }
        //如果$return为false, 则出错，将错误信息保存在属性errorMess中
        if(!$return)
          $this->errorMess=$this->getError();  
 
        return $return;
      }
    }
 
    /** 
     * 获取上传后的文件名称
     * @param  void   没有参数
     * @return string 上传后，新文件的名称， 如果是多文件上传返回数组
     */
    public function getFileName(){
      return $this->newFileName;
    }
 
    /**
     * 上传失败后，调用该方法则返回，上传出错信息
     * @param  void   没有参数
     * @return string  返回上传文件出错的信息报告，如果是多文件上传返回数组
     */
    public function getErrorMsg(){
      return $this->errorMess;
    }
 
    /* 设置上传出错信息 */
    private function getError() {
      $str = "上传文件<font color=&#39;red&#39;>{$this->originName}</font>时出错 : ";
      switch ($this->errorNum) {
        case 4: $str .= "没有文件被上传"; break;
        case 3: $str .= "文件只有部分被上传"; break;
        case 2: $str .= "上传文件的大小超过了HTML表单中MAX_FILE_SIZE选项指定的值"; break;
        case 1: $str .= "上传的文件超过了php.ini中upload_max_filesize选项限制的值"; break;
        case -1: $str .= "未允许类型"; break;
        case -2: $str .= "文件过大,上传的文件不能超过{$this->maxsize}个字节"; break;
        case -3: $str .= "上传失败"; break;
        case -4: $str .= "建立存放上传文件目录失败，请重新指定上传目录"; break;
        case -5: $str .= "必须指定上传文件的路径"; break;
        default: $str .= "未知错误";
      }
      return $str.&#39;<br>&#39;;
    }
 
    /* 设置和$_FILES有关的内容 */
    private function setFiles($name="", $tmp_name="", $size=0, $error=0) {
      $this->setOption(&#39;errorNum&#39;, $error);
      if($error)
        return false;
      $this->setOption(&#39;originName&#39;, $name);
      $this->setOption(&#39;tmpFileName&#39;,$tmp_name);
      $aryStr = explode(".", $name);
      $this->setOption(&#39;fileType&#39;, strtolower($aryStr[count($aryStr)-1]));
      $this->setOption(&#39;fileSize&#39;, $size);
      return true;
    }
 
    /* 为单个成员属性设置值 */
    private function setOption($key, $val) {
      $this->$key = $val;
    }
 
    /* 设置上传后的文件名称 */
    private function setNewFileName() {
      if ($this->israndname) {
        $this->setOption(&#39;newFileName&#39;, $this->proRandName());  
      } else{ 
        $this->setOption(&#39;newFileName&#39;, $this->originName);
      } 
    }
 
    /* 检查上传的文件是否是合法的类型 */
    private function checkFileType() {
      if (in_array(strtolower($this->fileType), $this->allowtype)) {
        return true;
      }else {
        $this->setOption(&#39;errorNum&#39;, -1);
        return false;
      }
    }
 
    /* 检查上传的文件是否是允许的大小 */
    private function checkFileSize() {
      if ($this->fileSize > $this->maxsize) {
        $this->setOption(&#39;errorNum&#39;, -2);
        return false;
      }else{
        return true;
      }
    }
 
    /* 检查是否有存放上传文件的目录 */
    private function checkFilePath() {
      if(empty($this->path)){
        $this->setOption(&#39;errorNum&#39;, -5);
        return false;
      }
      if (!file_exists($this->path) || !is_writable($this->path)) {
        if (!@mkdir($this->path, 0755)) {
          $this->setOption(&#39;errorNum&#39;, -4);
          return false;
        }
      }
      return true;
    }
 
    /* 设置随机文件名 */
    private function proRandName() {    
      $fileName = date(&#39;YmdHis&#39;)."_".rand(100,999);    
      return $fileName.&#39;.&#39;.$this->fileType; 
    }
 
    /* 复制上传文件到指定的位置 */
    private function copyFile() {
      if(!$this->errorNum) {
        $path = rtrim($this->path, &#39;/&#39;).&#39;/&#39;;
        $path .= $this->newFileName;
        if (@move_uploaded_file($this->tmpFileName, $path)) {
          return true;
        }else{
          $this->setOption(&#39;errorNum&#39;, -3);
          return false;
        }
      } else {
        return false;
      }
    }
  }

4. Application process of file upload class

The file upload class FileUpload in this example supports both single file upload and multiple file upload to the server together. There is no difference in processing methods. However, when writing an upload bid, multiple file uploads must be passed to the server in an array. The single file upload form is as follows:

<form action="upload.php" method="post" enctype="multipart/form-data" >
    name: <input type="text" name="username" value="" /><br>
    <input type="hidden" name="MAX_FILE_SIZE" value="1000000" />
    up pic: <input type="file" name="pic[]" value=""><br>
    up pic: <input type="file" name="pic[]" value=""><br>
    up pic: <input type="file" name="pic[]" value=""><br>
    up pic: <input type="file" name="pic[]" value=""><br>
 
    <input type="submit" value="upload" /><br>
 
</form>

The above forms all point the submission location to the same file upload.php, so it is not difficult to see that single and multiple file uploads are processed in the same way, upload. The php code is as follows:

<?php
    //包含一个文件上传类中的上传类
    include "fileupload.class.php";
 
    $up = new fileupload;
    //设置属性(上传的位置， 大小， 类型， 名是是否要随机生成)
    $up -> set("path", "./images/");
    $up -> set("maxsize", 2000000);
    $up -> set("allowtype", array("gif", "png", "jpg","jpeg"));
    $up -> set("israndname", false);
 
    //使用对象中的upload方法， 就可以上传文件， 方法需要传一个上传表单的名子 pic, 如果成功返回true, 失败返回false
    if($up -> upload("pic")) {
        echo &#39;<pre class="brush:php;toolbar:false">&#39;;
        //获取上传后文件名子
        var_dump($up->getFileName());
        echo &#39;

';       } else {         echo '

';
        //获取上传失败以后的错误提示
        var_dump($up->getErrorMsg());
        echo '

';     } ?>

In the upload.php file, you must first load the file fileupload.class.php where the file upload FileUpload class is located. Then instantiate the object of the file upload class, and then upload the file by calling the upload() method. If the upload is successful, you can get the uploaded file name through the getFileName() method. If the upload fails, you can also get the error through the getErrorMsg() method. Report. If you need to change some upload behaviors, you can complete the setting of some attributes by calling the set() method. The set() method can be used alone to set the value of an attribute. If you need to change the values ​​of multiple attributes, you can call the set() method continuously to set it, or you can set multiple attributes at the same time in a continuous operation.

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