如何在HTML中使用JavaScript显示PHP回声？

Question

I want to transfer PHP echo text into HTML through JavaScript.I've seen that it can be done with the function document.getelementbyid() and innerHTML but I tried and it did not work.

This PHP Code:

<?php
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$uploadOk = 1;
$imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);
// Check if image file is a actual image or fake image
if(isset($_POST["submit"])) {
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if($check !== false) {
        echo "File is an image - " . $check["mime"] . ".";
        $uploadOk = 1;
    } else {
        echo "File is not an image.";
        $uploadOk = 0;
    }
}
// Check if file already exists
if (file_exists($target_file)) {
    echo "Sorry, file already exists.";
    $uploadOk = 0;
}
// Check file size
if ($_FILES["fileToUpload"]["size"] > 500000) {
    echo "Sorry, your file is too large.";
    $uploadOk = 0;
}
// Allow certain file formats
if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
&& $imageFileType != "gif" ) {
    echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
    $uploadOk = 0;
}
// Check if $uploadOk is set to 0 by an error
if ($uploadOk == 0) {
    echo "Sorry, your file was not uploaded.";
// if everything is ok, try to upload file
} else {
if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
    echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";
} else {
    echo "Sorry, there was an error uploading your file.";
}
}
?>

I want to echo the text displays in HTML Without switching to upload.php!!

On id statusbar I want to show echo text!

This HTML code:

<form action="../assets/php/upload.php" method="post" enctype="multipart/form-data">
<label>Izaberi fotografiju:</label>
<input type="file" name="fileToUpload" id="fileToUpload">
<input type="submit" value="Upload Image" name="submit" onClick="info()">
<p id="statusbar"></p> 
</form>

Answer 1

You have to write code inside <?php ?> tag.Like this.

<script type="text/javascript">
 //js code..

     <?php echo "Sory, only PNG, JPG, GIF"; ?>

</scrip>

Answer 2

You can directly echo things to html. You can also echo things to a js variable directly like this, then set the html content with js.

<script>
  var string = <?php echo "Sory, only PNG, JPG, GIF"; ?>
  document.getElementById("notify-container").innerText = string;
</script>

Answer 3

Say your HTML element was the following: <div id="error"></div> , you'd assign the error message to a JavaScript variable like so: <script> var errorMsg = <?php echo "Sory, only PNG, JPG, GIF"; ?> </script> <script> var errorMsg = <?php echo "Sory, only PNG, JPG, GIF"; ?> </script> Then you can show the message like so: document.getElementById('error').innerHTML = errorMsg;

Answer 4

let's say you have to print this in your uploading html page

if ($uploadOk == 0) {
echo "Sorry, your file was not uploaded.";
// if everything is ok, try to upload file
}

change this to below

if ($uploadOk == 0) {
$message = "Sorry, your file was not uploaded.";
header("Location: /index.php?message="$message);
// if everything is ok, try to upload file
}

then get the message and print in your html page