Yii2实现UploadedFile上传文件示例

By admin in 计算机教程 on 2019年8月3日

闲来无事,整理了一下自己写的文件上传类。

在Yii里上传文件通常使用yii\web\UploadedFile类,它把每个上传的文件封装成UploadedFile对象。结合yii\webgets\ActiveForm和models,你可以轻松实现安全的上传文件机制。

通过

创建模型

  namespaceapp\models;

  use yii\base\Model;

  use yii\web\UploadedFile;

  class UploadForm extends Model{

   /**  

  *@var UploadedFile   file attribute

  */

  public $file;

  /**

  *@return array the validation rules

  */

  public function rules(){

  return[

              [[‘file’],’file’],

        ]; 

  }

}

imageFile属性用于接收上传的文件实例。它对应一条file验证规则.

UploadFile::getInstance($model, $attribute);

UploadFile::getInstances($model, $attribute);

UploadFile::getInstanceByName($name);

UploadFile::getInstancesByName($name);

渲染文件输出

<?php 

use yii\widgets\ActiveForm;

?>

<?php $form = ActiveForm::begin([‘options’ => [‘enctype’
=>’multipart/form-data’]]) ?>

<?= $form->field($model,’imageFile’)->fileInput() ?>

<button>上传</button>

<?php ActiveForm::end() ?>

需要注意的是要记得在表单选项里加入enctype属性以确保文件能被正常上传。fileInput()方法会渲染一个<input
type = ‘file’>标签,让用户可以选择一个文件上传。

把表单上传的文件赋值到  UploadedFile中的  private static $_files  中

视图和模型的连接

namespace app\controllers;

use Yii;

use yii\web\Controller;

use app\models\UploadForm;

use yii\web\UploadedFile;

class ReleseController extends Controller{

 publicfunctionactionUpload(){

 if ($_FILES) {

   $model_file->file = UploadedFile::getInstance($model_file,
‘file’);

    $filename = $model_file->file->name;

    $model_file->file->name = iconv(“utf-8”, “gb2312”,
$filename);//这里是处理中文的问题,非中文不需要

    if ($model_file->file && $model_file->validate()) {

      $rootPath = “../../file/uploads/”; //定义上传的根目录

       $ext = $model_file->file->extension; 
//获取文件的后缀(*格式*)

      $randName = time() . rand(1000, 9999) . “.” . $ext;
//重新编译文件名称

      $model_file->file->saveAs($rootPath . $randName);       
//调用内置封装类**执行上传

    }

     $model->cover =$randName; //存入数据库

   }

  }

}

/**
   * Returns an uploaded file for the given model attribute.
   * The file should be uploaded using [[\yii\widgets\ActiveField::fileInput()]].
   * @param \yii\base\Model $model the data model
   * @param string $attribute the attribute name. The attribute name may contain array indexes.
   * For example, '[1]file' for tabular file uploading; and 'file[1]' for an element in a file array.
   * @return UploadedFile the instance of the uploaded file.
   * Null is returned if no file is uploaded for the specified model attribute.
   * @see getInstanceByName()
   */
  public static function getInstance($model, $attribute)
  {
    $name = Html::getInputName($model, $attribute);
    return static::getInstanceByName($name);
  }

  /**
   * Returns all uploaded files for the given model attribute.
   * @param \yii\base\Model $model the data model
   * @param string $attribute the attribute name. The attribute name may contain array indexes
   * for tabular file uploading, e.g. '[1]file'.
   * @return UploadedFile[] array of UploadedFile objects.
   * Empty array is returned if no available file was found for the given attribute.
   */
  public static function getInstances($model, $attribute)
  {
    $name = Html::getInputName($model, $attribute);
    return static::getInstancesByName($name);
  }

  /**
   * Returns an uploaded file according to the given file input name.
   * The name can be a plain string or a string like an array element (e.g. 'Post[imageFile]', or 'Post[0][imageFile]').
   * @param string $name the name of the file input field.
   * @return UploadedFile the instance of the uploaded file.
   * Null is returned if no file is uploaded for the specified name.
   */
  public static function getInstanceByName($name)
  {
    $files = self::loadFiles();
    return isset($files[$name]) ? $files[$name] : null;
  }

  /**
   * Returns an array of uploaded files corresponding to the specified file input name.
   * This is mainly used when multiple files were uploaded and saved as 'files[0]', 'files[1]',
   * 'files[n]'..., and you can retrieve them all by passing 'files' as the name.
   * @param string $name the name of the array of files
   * @return UploadedFile[] the array of UploadedFile objects. Empty array is returned
   * if no adequate upload was found. Please note that this array will contain
   * all files from all sub-arrays regardless how deeply nested they are.
   */
  public static function getInstancesByName($name)
  {
    $files = self::loadFiles();
    if (isset($files[$name])) {
      return [$files[$name]];
    }
    $results = [];
    foreach ($files as $key => $file) {
      if (strpos($key, "{$name}[") === 0) {
        $results[] = $file;
      }
    }
    return $results;
  }

上传多个文件

loadFiles()方法,把$_FILES中的键值作为参数传递到loadFilesRecursive($key,
$names, $tempNames, $types, $sizes, $errors) 中

创建模型

在file验证规则里增加一个maxFiles选项,用以限制一次上传文件的最大数量

namespaceapp\models;

use yii\base\Model;

use yii\web\UploadedFile;

class UploadForm extends Model{

/**

*@var UploadedFile   file attribute

*/

public $file;

/**

*@return array the validation rules

*/

public function rules(){

return[

        [[‘file’],’file’,’maxFiles’=>4],

    ];

  }

}

/**
   * Creates UploadedFile instances from $_FILE.
   * @return array the UploadedFile instances
   */
  private static function loadFiles()
  {
    if (self::$_files === null) {
      self::$_files = [];
      if (isset($_FILES) && is_array($_FILES)) {
        foreach ($_FILES as $class => $info) {
          self::loadFilesRecursive($class, $info['name'], $info['tmp_name'], $info['type'], $info['size'], $info['error']);
        }
      }
    }
    return self::$_files;
  }

视图

把multiple选项添加到fileInput()函数调用里,这样文件输入控件就可以接收多个文件。

<?php

use yii\widgets\ActiveForm;

?>

<?php $form = ActiveForm::begin([‘options’ => [‘enctype’
=>’multipart/form-data’]]) ?>

<?=
$form->field($model,’imageFiles[]’)->fileInput([‘multiple’=>true,’accept’=>’image/*’])
?>

<button>上传</button>

<?php ActiveForm::end() ?>

loadFilesRecursive方法,通过递归把$_FILES中的内容保存到  self::$_files

视图与模型连接

在控制器的 action 方法中,你应该调用 UploadedFile::getInstances 而不是
UploadedFile::getInstance() 来把 UploadedFile 实例数组赋值给
UploadForm::imageFiles。

namespace app\controllers;

use Yii;

use yii\web\Controller;

use app\models\UploadForm;

use yii\web\UploadedFile;

class ReleseController extends Controller{

  publicfunctionactionUpload(){

   if ($_FILES) {

  $model_file->file = UploadedFile::getInstances($model_file,
‘file’);

   $filename = $model_file->file->name;

   $model_file->file->name = iconv(“utf-8”, “gb2312”,
$filename);//这里是处理中文的问题,非中文不需要

      if ($model_file->file && $model_file->validate()) {

       $rootPath = “../../file/uploads/”; //定义上传的根目录

       $ext = $model_file->file->extension;  
//获取文件的后缀(*格式*)

        $randName = time() . rand(1000, 9999) . “.” . $ext;
//重新编译文件名称

       $model_file->file->saveAs($rootPath . $randName);       
//调用内置封装类**执行上传

     }

   $model->cover =$randName; //存入数据库

 }

 }

}

/**
   * Creates UploadedFile instances from $_FILE recursively.
   * @param string $key key for identifying uploaded file: class name and sub-array indexes
   * @param mixed $names file names provided by PHP
   * @param mixed $tempNames temporary file names provided by PHP
   * @param mixed $types file types provided by PHP
   * @param mixed $sizes file sizes provided by PHP
   * @param mixed $errors uploading issues provided by PHP
   */
  private static function loadFilesRecursive($key, $names, $tempNames, $types, $sizes, $errors)
  {
    if (is_array($names)) {
      foreach ($names as $i => $name) {
        self::loadFilesRecursive($key . '[' . $i . ']', $name, $tempNames[$i], $types[$i], $sizes[$i], $errors[$i]);
      }
    } elseif ($errors !== UPLOAD_ERR_NO_FILE) {
      self::$_files[$key] = new static([
        'name' => $names,
        'tempName' => $tempNames,
        'type' => $types,
        'size' => $sizes,
        'error' => $errors,
      ]);
    }
  }

实例:

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