Your question is very broad. However, I'll do my best to answer it:
You have 3 logical layers to your problem here:
- The HTML that creates the user interface
- The Javascript - that handles processing and sending your images (or any file) to another place.
- Your PHP code, which will accept your images and process/save them to your server.
A brief overview of how to approach the solution:
Build a form in HTML with a file upload field.
<form method="post" enctype="multipart/form-data">
<input type="file" name="files[]" multiple>
<input type="submit" value="Upload File" name="submit">
</form>
In your HTML file, write or include Javascript that will serialise the form data, and POST it to your PHP file.
<script type="text/javascript">
const url = 'process.php';
const form = document.querySelector('form');
form.addEventListener('submit', e => {
e.preventDefault();
const files = document.querySelector('[type=file]').files;
const formData = new FormData();
for (let i = 0; i < files.length; i++) {
let file = files[i];
formData.append('files[]', file);
}
// Uses browser's built in Fetch API - you can replace this with jQuery or whatever you choose.
fetch(url, {
method: 'POST',
body: formData
}).then(response => {
console.log(response);
});
});
</script>
Write the logic into a new PHP file (called process.php) to handle the form data (images) as appropriate.
<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
if (isset($_FILES['files'])) {
$errors = [];
$path = 'uploads/';
$extensions = ['jpg', 'jpeg', 'png', 'gif'];
$all_files = count($_FILES['files']['tmp_name']);
$fileNames = [];
for ($i = 0; $i < $all_files; $i++) {
$file_name = $_FILES['files']['name'][$i];
$file_tmp = $_FILES['files']['tmp_name'][$i];
$file_type = $_FILES['files']['type'][$i];
$file_size = $_FILES['files']['size'][$i];
$file_ext = strtolower(end(explode('.', $_FILES['files']['name'][$i])));
$fileNames[] = $file_name;
$file = $path . $file_name;
if (!in_array($file_ext, $extensions)) {
$errors[] = 'Extension not allowed: ' . $file_name . ' ' . $file_type;
}
if ($file_size > 2097152) {
$errors[] = 'File size exceeds limit: ' . $file_name . ' ' . $file_type;
}
if (empty($errors)) {
move_uploaded_file($file_tmp, $file);
}
}
if ($errors) {
print_r($errors);
} else {
print_r(json_encode(['file_names' => $fileNames]));
}
}
}
For speed - the example code in this solution was taken from https://www.taniarascia.com/how-to-upload-files-to-a-server-with-plain-javascript-and-php/
For other examples - you could check out StackOverflow's other questions. Here's a similar one to yours: uploading image using javascript