Do Image Files in Site Assets Need to Be Checked in After Uploading
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In this commodity, I'll explicate the basics of file upload in PHP. Firstly, we'll go through the PHP configuration options that need to be in place for successful file uploads. Following that, we'll develop a existent-globe example of how to upload a file.
Configure the PHP Settings
There are a couple of PHP configuration settings that you'll want to check beforehand for successful file uploads. In this department, we'll go through every important choice in regards to PHP file upload. These options can be configured in the php.ini file.
If y'all're non sure where to detect yourphp.ini file, you tin use thephp_ini_loaded_file() to locate it. Simply create a PHP file on your server with the post-obit line, and open up it from the browser.
<?php echo php_ini_loaded_file(); ?>
Here'south an excerpt from a setup file with some useful defaults.
; Whether to let HTTP file uploads. file_uploads = On ; Temporary directory for HTTP uploaded files. ; Volition use arrangement default if not set. ;upload_tmp_dir = ; Maximum immune size for uploaded files. upload_max_filesize = 16M ; Maximum number of files that tin be uploaded via a single request max_file_uploads = xx ; Maximum size of Post data that PHP will accept. post_max_size = 20M max_input_time = 60 memory_limit = 128M max_execution_time = thirty
The Key Settings
file_uploads
The value of thefile_uploads directive should be set toOn to allow file uploads. The default value of this directive isOn.
upload_max_filesize
Theupload_max_filesize directive allows you lot to configure the maximum size of the uploaded file. By default, it'south fix to2M (two megabytes), and you tin override this setting using the.htaccess file as well. Ii megabytes isn't very much by today's standards, so you might have to increase this. If y'all get an fault thatfile exceeds upload_max_filesize when you try to upload a file, you need to increase this value. If you do, be sure to also increasepost_max_size (see below).
upload_tmp_dir
Sets a temporary directory which will be used to store uploaded files. In most cases, you don't need to worry about this setting. If yous don't fix it, the system default temp directory will be used.
post_max_size
Thepost_max_size directive allows y'all to configure the maximum size of Postal service data. Since files are uploaded with POST requests, this value must exist greater than what you've set for theupload_max_filesize directive. For case, if yourupload_max_filesize is16M (16 megabytes), yous might want to setpost_max_size to20M.
max_file_uploads
It allows you lot to set the maximum number of files that tin exist uploaded at a time. The default istwenty, a sensible amount.
max_input_time
It's the maximum number of seconds a script is allowed to parse the input data. You should prepare it to a reasonable value if y'all're dealing with large file uploads.threescore (60 seconds) is a skillful value for most apps.
memory_limit
Thememory_limit directive indicates the maximum amount of memory a script can swallow. If you're facing issues when uploading large files, y'all need to make sure that the value of this directive is greater than what yous've ready for the post_max_size directive. The default value is128M (128 megabytes), so unless you take a very bigpost_max_size andupload_max_filesize, you don't demand to worry virtually this.
max_execution_time
It's the maximum number of seconds a script is immune to run. If y'all're facing issues when uploading large files, you can consider increasing this value. 30 (30 seconds) should piece of work well for most apps.
Now permit's build a real-world example to demonstrate file upload in PHP.
Create the HTML Grade
Once you've configured the PHP settings, you're ready to try out the PHP file upload capabilities.
Our GitHub repo has some sample code which I'g going to discuss throughout this article. So, if you want to follow along, get ahead and download information technology from GitHub.
Nosotros're going to create two PHP files:index.php andupload.php. Theindex.php file holds code which is responsible for displaying the file upload form. On the other hand, theupload.php file is responsible for uploading a file to the server.
As well, a file volition be uploaded in theuploaded_files directory, so you demand to brand sure that this binder exists and is writable by theweb-server user.
In this section, we'll go through the key parts of thealphabetize.php file.
Let'southward take a await at theindex.php file on GitHub:
<?php session_start(); ?> <!DOCTYPE html> <html> <caput> <title>PHP File Upload</title> </head> <trunk> <?php if (isset($_SESSION['bulletin']) && $_SESSION['message']) { echo '<p course="notification">'.$_SESSION['message']).'</p>'; unset($_SESSION['message']); } ?> <grade method="POST" activity="upload.php" enctype="multipart/course-information"> <div class="upload-wrapper"> <bridge class="file-proper noun">Choose a file...</bridge> <characterization for="file-upload">Browse<input type="file" id="file-upload" proper noun="uploadedFile"></label> </div> <input type="submit" proper noun="uploadBtn" value="Upload" /> </form> </body> </html> You can use the following CSS to give the class a more appealing look.
div.upload-wrapper { color: white; font-weight: bold; brandish: flex; } input[blazon="file"] { position: absolute; left: -9999px; } input[blazon="submit"] { border: 3px solid #555; colour: white; background: #666; margin: 10px 0; border-radius: 5px; font-weight: bold; padding: 5px 20px; cursor: pointer; } input[type="submit"]:hover { background: #555; } label[for="file-upload"] { padding: 0.7rem; display: inline-block; groundwork: #fa5200; cursor: pointer; border: 3px solid #ca3103; border-radius: 0 5px 5px 0; border-left: 0; } label[for="file-upload"]:hover { background: #ca3103; } span.file-name { padding: 0.7rem 3rem 0.7rem 0.7rem; white-space: nowrap; overflow: hidden; background: #ffb543; color: black; border: 3px solid #f0980f; border-radius: 5px 0 0 5px; edge-right: 0; } The CSS basically hides the original fileinput and styles its accompanyingspan andlabel elements.
Although it may expect like a typical PHP form, there's an important deviation in the value of theenctype aspect of the<form> tag. It needs to be set tomultipart/class-data since the class contains the file field.
Theenctype aspect specifies the type of encoding which should exist used when the form is submitted, and information technology takes one of the following three values:
-
application/x-www-form-urlencoded: This is the default value when you lot don't ready the value of theenctypeattribute explicitly. In this example, characters are encoded before it's sent to the server. If you don't have the file field in your form, you should use this value for theenctypeaspect. -
multipart/grade-data: When you employ themultipart/course-informationvalue for theenctypeattribute, it allows you to upload files using the Mail method. Also, it makes certain that the characters are not encoded when the grade is submitted. -
text/plain: This is generally non used. With this setting, the information is sent unencoded.
Adjacent, nosotros output the file field, which allows you to select a file from your figurer.
<input type="file" name="uploadedFile" />
Apart from that, nosotros've displayed a bulletin at the top of the form. This message shows the status of the file upload, and information technology'll be set in a session variable by theupload.php script. We'll look more at this in the next section.
<?php if (isset($_SESSION['message']) && $_SESSION['bulletin']) { repeat '<p class="notification">'.$_SESSION['message']).'</p>'; unset($_SESSION['message']); } ?> So that sums up thealphabetize.php file. In the next department, we'll see how to handle the uploaded file on the server side.
Create the Upload Logic
In the previous section, we created the HTML form which is displayed on the client side and allows yous to upload a file from your computer. In this section, nosotros'll meet the server-side counterpart which allows y'all to handle the uploaded file.
Pull in the code from theupload.php file on GitHub. We'll become through the important parts of that file.
In theupload.php file, nosotros've checked whether it's a valid POST asking in the first identify.
if (isset($_POST['uploadBtn']) && $_POST['uploadBtn'] == 'Upload') { ... } In PHP, when a file is uploaded, the$_FILES superglobal variable is populated with all the data about the uploaded file. It'due south initialized as an array and may incorporate the following information for successful file upload.
-
tmp_name: The temporary path where the file is uploaded is stored in this variable. -
proper name: The bodily proper noun of the file is stored in this variable. -
size: Indicates the size of the uploaded file in bytes. -
type: Contains the mime type of the uploaded file. -
error: If there'due south an error during file upload, this variable is populated with the advisable error message. In the case of successful file upload, it contains 0, which you can compare by using theUPLOAD_ERR_OKconstant.
Afterward validating the Mail asking, we check that the file upload was successful.
if (isset($_FILES['uploadedFile']) && $_FILES['uploadedFile']['fault'] === UPLOAD_ERR_OK) { ... } You can see that the$_FILES variable is a multi-dimensional array, the first element is the name of the file field, and the second element has the data most the uploaded file, equally we've just discussed to a higher place.
If the file upload is successful, nosotros initialize a few variables with data about the uploaded file.
// get details of the uploaded file $fileTmpPath = $_FILES['uploadedFile']['tmp_name']; $fileName = $_FILES['uploadedFile']['name']; $fileSize = $_FILES['uploadedFile']['size']; $fileType = $_FILES['uploadedFile']['blazon']; $fileNameCmps = explode(".", $fileName); $fileExtension = strtolower(finish($fileNameCmps)); In the above snippet, we've also figured out the extension of the uploaded file and stored it in the$fileExtension variable.
As the uploaded file may contain spaces and other special characters, it'south better to sanitize the filename, and that's exactly we've washed in the following snippet.
$newFileName = md5(fourth dimension() . $fileName) . '.' . $fileExtension;
Information technology's important that you restrict the type of file which can be uploaded to certain extensions and don't permit everything using the upload form. Nosotros've washed that past checking the extension of the uploaded file with a set of extensions that we want to allow for uploading.
$allowedfileExtensions = array('jpg', 'gif', 'png', 'naught', 'txt', 'xls', 'doc'); if (in_array($fileExtension, $allowedfileExtensions)) { ... } Finally, nosotros apply themove_uploaded_file function to move the uploaded file to the specific location of our pick.
// directory in which the uploaded file will be moved $uploadFileDir = './uploaded_files/'; $dest_path = $uploadFileDir . $newFileName; if(move_uploaded_file($fileTmpPath, $dest_path)) { $message ='File is successfully uploaded.'; } else { $bulletin = 'There was some error moving the file to upload directory. Please brand sure the upload directory is writable by web server.'; } Themove_uploaded_file function takes two arguments. The first statement is the filename of the uploaded file, and the second statement is the destination path where you desire to move the file.
Finally, we redirect the user to theindex.php file. Likewise, we set the appropriate bulletin in the session variable, which will be displayed to users later on redirection in theindex.php file.
How It All Works Together
Don't forget to create theuploaded_files directory and arrive writable past theweb-server user. Next, get ahead and run theindex.php file, which should display the file upload class which looks like this:
Click on theScan button—that should open a dialog box which allows y'all to select a file from your figurer. Select a file with one of the extensions allowed in our script, and click on theUpload button.
That should submit the course, and if everything goes well, yous should see the uploaded file in theuploaded_files directory. You could also try uploading other files with extensions that are not allowed, and bank check if our script prevents such uploads.
Resolving Mutual Errors
A lot of things can become wrong during a file upload which might consequence in errors. You lot can cheque the exact mistake that occurred during the upload using$_FILES['uploadedFile']['mistake']. Here is the explanation of those errors:
File Is Too Big
UPLOAD_ERR_INI_SIZE andUPLOAD_ERR_FORM_SIZE occur when the size of an uploaded file is more than the value specified in php.ini or the HTML grade respectively. You can get rid of this mistake past increasing the upload size limits or letting users know near them beforehand.
Temporary Folder Is Missing
UPLOAD_ERR_NO_TMP_DIR is reported when the temporary folder to upload the file is missing.UPLOAD_ERR_NO_FILE is reported when at that place is no file to upload.
Partial Upload or Can't Write to Disk
You will getUPLOAD_ERR_PARTIAL if the file could only exist uploaded partially andUPLOAD_ERR_CANT_WRITE if the file could not exist written to the disk.
A PHP Extension Stopped the File Upload
Sometimes, you will get the errorUPLOAD_ERR_EXTENSION because some extension stopped the file upload. This one volition require more investigation by you to figure out which extension caused the trouble.
Here is the total lawmaking fromupload.php which will evidence users a message on the upload page in example of success or failure of the upload. The information almost the success or failure of the upload is stored in the$_SESSION['message'].
<?php session_start(); $bulletin = ''; if (isset($_POST['uploadBtn']) && $_POST['uploadBtn'] == 'Upload') { if (isset($_FILES['uploadedFile']) && $_FILES['uploadedFile']['error'] === UPLOAD_ERR_OK) { // get details of the uploaded file $fileTmpPath = $_FILES['uploadedFile']['tmp_name']; $fileName = $_FILES['uploadedFile']['name']; $fileSize = $_FILES['uploadedFile']['size']; $fileType = $_FILES['uploadedFile']['type']; $fileNameCmps = explode(".", $fileName); $fileExtension = strtolower(end($fileNameCmps)); // sanitize file-name $newFileName = md5(time() . $fileName) . '.' . $fileExtension; // check if file has one of the following extensions $allowedfileExtensions = array('jpg', 'gif', 'png', 'nada', 'txt', 'xls', 'doc'); if (in_array($fileExtension, $allowedfileExtensions)) { // directory in which the uploaded file will be moved $uploadFileDir = './uploaded_files/'; $dest_path = $uploadFileDir . $newFileName; if(move_uploaded_file($fileTmpPath, $dest_path)) { $bulletin ='File is successfully uploaded.'; } else { $bulletin = 'There was some mistake moving the file to upload directory. Delight brand certain the upload directory is writable by web server.'; } } else { $message = 'Upload failed. Immune file types: ' . implode(',', $allowedfileExtensions); } } else { $bulletin = 'There is some error in the file upload. Please check the following mistake.<br>'; $message .= 'Error:' . $_FILES['uploadedFile']['error']; } } $_SESSION['message'] = $message; header("Location: index.php"); Learn PHP With a Complimentary Online Course
Today, we discussed the basics of file upload in PHP. In the start half of the article, we discussed the different configuration options that need to exist in place for file upload to work. Then we looked at a real-earth instance which demonstrated how file upload works in PHP.
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Source: https://code.tutsplus.com/tutorials/how-to-upload-a-file-in-php-with-example--cms-31763
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