显示更改配置文件图片失败的错误

Question

当我们上传不允许或超过允许大小的文件类型时，我试图使用javaScript显示错误。虽然如果不满足条件但不会上传图像，但也不会显示错误。

的functions.php

<?php
function createDir($path) {
    if (! file_exists ( $path )) {
        $old_mask = umask ( 0 );
        mkdir ( $path, 0777, TRUE );
        umask ( $old_mask );
    }
}
function createThumb($path1, $path2, $file_type, $new_w, $new_h, $squareSize = '') {
    /* read the source image */
    $source_image = FALSE;

    if (preg_match ( "/jpg|JPG|jpeg|JPEG/", $file_type )) {
        $source_image = imagecreatefromjpeg ( $path1 );
    } elseif (preg_match ( "/png|PNG/", $file_type )) {

        if (! $source_image = @imagecreatefrompng ( $path1 )) {
            $source_image = imagecreatefromjpeg ( $path1 );
        }
    } elseif (preg_match ( "/gif|GIF/", $file_type )) {
        $source_image = imagecreatefromgif ( $path1 );
    }
    if ($source_image == FALSE) {
        $source_image = imagecreatefromjpeg ( $path1 );
    }

    $orig_w = imageSX ( $source_image );
    $orig_h = imageSY ( $source_image );

    if ($orig_w < $new_w && $orig_h < $new_h) {
        $desired_width = $orig_w;
        $desired_height = $orig_h;
    } else {
        $scale = min ( $new_w / $orig_w, $new_h / $orig_h );
        $desired_width = ceil ( $scale * $orig_w );
        $desired_height = ceil ( $scale * $orig_h );
    }

    if ($squareSize != '') {
        $desired_width = $desired_height = $squareSize;
    }

    /* create a new, "virtual" image */
    $virtual_image = imagecreatetruecolor ( $desired_width, $desired_height );
    // for PNG background white----------->
    $kek = imagecolorallocate ( $virtual_image, 255, 255, 255 );
    imagefill ( $virtual_image, 0, 0, $kek );

    if ($squareSize == '') {
        /* copy source image at a resized size */
        imagecopyresampled ( $virtual_image, $source_image, 0, 0, 0, 0, $desired_width, $desired_height, $orig_w, $orig_h );
    } else {
        $wm = $orig_w / $squareSize;
        $hm = $orig_h / $squareSize;
        $h_height = $squareSize / 2;
        $w_height = $squareSize / 2;

        if ($orig_w > $orig_h) {
            $adjusted_width = $orig_w / $hm;
            $half_width = $adjusted_width / 2;
            $int_width = $half_width - $w_height;
            imagecopyresampled ( $virtual_image, $source_image, - $int_width, 0, 0, 0, $adjusted_width, $squareSize, $orig_w, $orig_h );
        } 

        elseif (($orig_w <= $orig_h)) {
            $adjusted_height = $orig_h / $wm;
            $half_height = $adjusted_height / 2;
            imagecopyresampled ( $virtual_image, $source_image, 0, 0, 0, 0, $squareSize, $adjusted_height, $orig_w, $orig_h );
        } else {
            imagecopyresampled ( $virtual_image, $source_image, 0, 0, 0, 0, $squareSize, $squareSize, $orig_w, $orig_h );
        }
    }

    if (@imagejpeg ( $virtual_image, $path2, 90 )) {
        imagedestroy ( $virtual_image );
        imagedestroy ( $source_image );
        return TRUE;
    } else {
        return FALSE;
    }
}
?>

upload.php的

if ($_FILES ['image_upload_file'] ["error"] > 0) {
    $output ['error'] = "Error in File";
} elseif (! in_array ( $_FILES ['image_upload_file'] ["type"], $allowedImageType )) {
    $output ['error'] = "You can only upload JPG, PNG and GIF file";
} elseif (round ( $_FILES ['image_upload_file'] ["size"] / 1024 ) > 4096) {
    $output ['error'] = "You can upload file size up to 4 MB";
} else {
    /* create directory with 777 permission if not exist - start */
    createDir ( IMAGE_SMALL_DIR );
    createDir ( IMAGE_MEDIUM_DIR );
    /* create directory with 777 permission if not exist - end */
    $path [0] = $_FILES ['image_upload_file'] ['tmp_name'];
    $file = pathinfo ( $_FILES ['image_upload_file'] ['name'] );
    $fileType = $file ["extension"];
    $desiredExt = 'jpg';
    $fileNameNew = rand ( 333, 999 ) . time () . ".$desiredExt";
    $path [1] = IMAGE_MEDIUM_DIR . $fileNameNew;
    $path [2] = IMAGE_SMALL_DIR . $fileNameNew;

    if (createThumb ( $path [0], $path [1], $fileType, IMAGE_MEDIUM_SIZE, IMAGE_MEDIUM_SIZE, IMAGE_MEDIUM_SIZE )) {

        if (createThumb ( $path [1], $path [2], "$desiredExt", IMAGE_SMALL_SIZE, IMAGE_SMALL_SIZE, IMAGE_SMALL_SIZE )) {
            $output ['status'] = TRUE;
            $output ['image_medium'] = $path [1];
            $output ['image_small'] = $path [2];
        }
    }
}
echo json_encode ( $output );
    }

的settings.php

<script>
$(document).on('change', '#image_upload_file', function () {
var progressBar = $('.progressBar'), bar = $('.progressBar .bar'), percent =  $('.progressBar .percent');
$('#image_upload_form').ajaxForm({
beforeSend: function() {
progressBar.fadeIn();
var percentVal = '0%';
bar.width(percentVal)
percent.html(percentVal);
},
uploadProgress: function(event, position, total, percentComplete) {
var percentVal = percentComplete + '%';
bar.width(percentVal)
percent.html(percentVal);
},
success: function(html, statusText, xhr, $form) {   
obj = $.parseJSON(html);  
if(obj.status){   
var percentVal = '100%';
bar.width(percentVal)
percent.html(percentVal);
$("#imgArea>img").prop('src',obj.image_medium);     
}else{
alert(obj.error);
}
},
complete: function(xhr) {
progressBar.fadeOut();      
} 
}).submit();    
});
</script>