先看一个Yii2中UploadedFile的源文件
<?php
/**
* @link http://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
namespace yii\web;
use Yii;
use yii\base\BaseObject;
use yii\helpers\ArrayHelper;
use yii\helpers\Html;
/**
* UploadedFile represents the information for an uploaded file.
*
* You can call [[getInstance()]] to retrieve the instance of an uploaded file,
* and then use [[saveAs()]] to save it on the server.
* You may also query other information about the file, including [[name]],
* [[tempName]], [[type]], [[size]] and [[error]].
*
* For more details and usage information on UploadedFile, see the [guide article on handling uploads](guide:input-file-upload).
*
* @property-read string $baseName Original file base name. This property is read-only.
* @property-read string $extension File extension. This property is read-only.
* @property-read bool $hasError Whether there is an error with the uploaded file. Check [[error]] for
* detailed error code information. This property is read-only.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
class UploadedFile extends BaseObject
{
/**
* @var string the original name of the file being uploaded
*/
public $name;
/**
* @var string the path of the uploaded file on the server.
* Note, this is a temporary file which will be automatically deleted by PHP
* after the current request is processed.
*/
public $tempName;
/**
* @var string the MIME-type of the uploaded file (such as "image/gif").
* Since this MIME type is not checked on the server-side, do not take this value for granted.
* Instead, use [[\yii\helpers\FileHelper::getMimeType()]] to determine the exact MIME type.
*/
public $type;
/**
* @var int the actual size of the uploaded file in bytes
*/
public $size;
/**
* @var int an error code describing the status of this file uploading.
* @see https://secure.php.net/manual/en/features.file-upload.errors.php
*/
public $error;
/**
* @var resource a temporary uploaded stream resource used within PUT and PATCH request.
*/
private $_tempResource;
private static $_files;
/**
* UploadedFile constructor.
*
* @param array $config name-value pairs that will be used to initialize the object properties
*/
public function __construct($config = [])
{
$this->_tempResource = ArrayHelper::remove($config, 'tempResource');
parent::__construct($config);
}
/**
* String output.
* This is PHP magic method that returns string representation of an object.
* The implementation here returns the uploaded file's name.
* @return string the string representation of the object
*/
public function __toString()
{
return $this->name;
}
/**
* 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 $attribute the attribute name. The attribute name may contain array indexes.
* For example, '[1]file' for tabular file uploading; and 'file[1]' for an element in a file array.
* @return null|UploadedFile the instance of the uploaded file.
* Null is returned if no file is uploaded for the specified model attribute.
* @see getInstanceByName()
*/
public static function getInstance($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 $name the name of the file input field.
* @return null|UploadedFile the instance of the uploaded file.
* Null is returned if no file is uploaded for the specified name.
*/
public static function getInstanceByName($name)
{
$files = self::loadFiles();
return isset($files[$name]) ? new static($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[$name])) {
return [new static($files[$name])];
}
$results = [];
foreach ($files as $key => $file) {
if (strpos($key, "{$name}[") === 0) {
$results[] = new static($file);
}
}
return $results;
}
/**
* Cleans up the loaded UploadedFile instances.
* This method is mainly used by test scripts to set up a fixture.
*/
public static function reset()
{
self::$_files = null;
}
/**
* Saves the uploaded file.
* If the target file `$file` already exists, it will be overwritten.
* @param string $file the file path or a path alias used to save the uploaded file.
* @param bool $deleteTempFile whether to delete the temporary file after saving.
* If true, you will not be able to save the uploaded file again in the current request.
* @return bool true whether the file is saved successfully
* @see error
*/
public function saveAs($file, $deleteTempFile = true)
{
if ($this->hasError) {
return false;
}
$targetFile = Yii::getAlias($file);
if (is_resource($this->_tempResource)) {
$result = $this->copyTempFile($targetFile);
return $deleteTempFile ? @fclose($this->_tempResource) : (bool) $result;
}
return $deleteTempFile ? move_uploaded_file($this->tempName, $targetFile) : copy($this->tempName, $targetFile);
}
/**
* Copy temporary file into file specified
*
* @param string $targetFile path of the file to copy to
* @return bool|int the total count of bytes copied, or false on failure
* @since 2.0.32
*/
protected function copyTempFile($targetFile)
{
$target = fopen($targetFile, 'wb');
if ($target === false) {
return false;
}
$result = stream_copy_to_stream($this->_tempResource, $target);
@fclose($target);
return $result;
}
/**
* @return string original file base name
*/
public function getBaseName()
{
// https://github.com/yiisoft/yii2/issues/11012
$pathInfo = pathinfo('_' . $this->name, PATHINFO_FILENAME);
return mb_substr($pathInfo, 1, mb_strlen($pathInfo, '8bit'), '8bit');
}
/**
* @return string file extension
*/
public function getExtension()
{
return strtolower(pathinfo($this->name, PATHINFO_EXTENSION));
}
/**
* @return bool whether there is an error with the uploaded file.
* Check [[error]] for detailed error code information.
*/
public function getHasError()
{
return $this->error != UPLOAD_ERR_OK;
}
/**
* 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) {
$resource = isset($info['tmp_resource']) ? $info['tmp_resource'] : [];
self::loadFilesRecursive($class, $info['name'], $info['tmp_name'], $info['type'], $info['size'], $info['error'], $resource);
}
}
}
return self::$_files;
}
/**
* 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, $tempResources)
{
if (is_array($names)) {
foreach ($names as $i => $name) {
$resource = isset($tempResources[$i]) ? $tempResources[$i] : [];
self::loadFilesRecursive($key . '[' . $i . ']', $name, $tempNames[$i], $types[$i], $sizes[$i], $errors[$i], $resource);
}
} elseif ((int) $errors !== UPLOAD_ERR_NO_FILE) {
self::$_files[$key] = [
'name' => $names,
'tempName' => $tempNames,
'tempResource' => $tempResources,
'type' => $types,
'size' => $sizes,
'error' => $errors,
];
}
}
}
使用后发现取所有上传的文件，比较接近的就是getInstancesByName($name)了，但是这个接口的参数是必填的，且不能为空，否则会出现找不到上传的文件！
这个用于传统的form表单项目是没有问题的！
但是，在做app开发时，一般是前后端分离的，且前端可能会使用类似于uniapp这样的框架去上传文件，它里面无法构造出像"file[]"这样的键名来表示一次上传多个同name的附件信息，
想来想去，实在没招了，同时又看到此类中的这个实现，无非是加了一层name过滤，那我如果不作过滤，岂不是就能实现获取所有上传的文件了！因此，只要重新写个这个方法的实现就可以了！
鉴于这个类源码的实现我们一般不做修改，所以就新建一个子类来覆盖这个方法吧，开工：
<?php
namespace common\components;
class UploadedFile extends \yii\web\UploadedFile
{
private static $_files;
/**
* 获取上传的文件列表(重写父接口, 使其使用范围更广)
* @param null $name 为null或''时获取所有上传的文件, 否则只获取指定$name的上传文件
* @return array
*/
public static function getInstancesByName($name = null): array
{
$files = self::loadFiles();
if ($name && isset($files[$name])) {
return [new static($files[$name])];
}
$results = [];
foreach ($files as $key => $file) {
if (!$name || str_starts_with($key, "{$name}[")) {
$results[] = new static($file);
}
}
return $results;
}
/**
* 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) {
$resource = isset($info['tmp_resource']) ? $info['tmp_resource'] : [];
self::loadFilesRecursive($class, $info['name'], $info['tmp_name'], $info['type'], $info['size'], $info['error'], $resource);
}
}
}
return self::$_files;
}
/**
* 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, $tempResources)
{
if (is_array($names)) {
foreach ($names as $i => $name) {
$resource = isset($tempResources[$i]) ? $tempResources[$i] : [];
self::loadFilesRecursive($key . '[' . $i . ']', $name, $tempNames[$i], $types[$i], $sizes[$i], $errors[$i], $resource);
}
} elseif ((int) $errors !== UPLOAD_ERR_NO_FILE) {
self::$_files[$key] = [
'name' => $names,
'tempName' => $tempNames,
'tempResource' => $tempResources,
'type' => $types,
'size' => $sizes,
'error' => $errors,
];
}
}
}
运行后经过多次测试，发现已经可以实现我说的这个需求了：
就是当调用getInstancesByName() 时，如果传入的name为null或''， 就会去取上传的所有文件，如果指定了name，就能获取指定name的多个文件，与基类实现一致！
因此，此扩展写法还是非常成功的，在不改变基类用法的前提下，增加了使用范围！Very Good!