Link Parent Record With Child Image Files - php

Question

I wonder whether someone can help me please.
I've created this form which allows users to record details about a specific location they've visited and as each location is saved a unique incrementing 'locationid' is saved as part of the mySQL record.
I've extended this further and when they click on the add 'Add Image' Button they will be able to save image files connected to the 'location' record created. This is done via the code below which saved the original image file and thumbnail version into a folder on my server.
<?php
//define a maxim size for the uploaded images
//define ("MAX_SIZE","100");
// define the width and height for the thumbnail
// note that theese dimmensions are considered the maximum dimmension and are not fixed,
// because we have to keep the image ratio intact or it will be deformed
define ("WIDTH","150");
define ("HEIGHT","100");
// this is the function that will create the thumbnail image from the uploaded image
// the resize will be done considering the width and height defined, but without deforming the image
function make_thumb($img_name,$filename,$new_w,$new_h)
{
//get image extension.
$ext=getExtension($img_name);
//creates the new image using the appropriate function from gd library
if(!strcmp("jpg",$ext) || !strcmp("jpeg",$ext))
$src_img=imagecreatefromjpeg($img_name);
if(!strcmp("png",$ext))
$src_img=imagecreatefrompng($img_name);
//gets the dimmensions of the image
$old_x=imageSX($src_img);
$old_y=imageSY($src_img);
// next we will calculate the new dimmensions for the thumbnail image
// the next steps will be taken:
// 1. calculate the ratio by dividing the old dimmensions with the new ones
// 2. if the ratio for the width is higher, the width will remain the one define in WIDTH variable
// and the height will be calculated so the image ratio will not change
// 3. otherwise we will use the height ratio for the image
// as a result, only one of the dimmensions will be from the fixed ones
$ratio1=$old_x/$new_w;
$ratio2=$old_y/$new_h;
if($ratio1>$ratio2) {
$thumb_w=$new_w;
$thumb_h=$old_y/$ratio1;
}
else {
$thumb_h=$new_h;
$thumb_w=$old_x/$ratio2;
}
// we create a new image with the new dimmensions
$dst_img=ImageCreateTrueColor($thumb_w,$thumb_h);
// resize the big image to the new created one
imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y);
// output the created image to the file. Now we will have the thumbnail into the file named by $filename
if(!strcmp("png",$ext))
imagepng($dst_img,$filename);
else
imagejpeg($dst_img,$filename);
//destroys source and destination images.
imagedestroy($dst_img);
imagedestroy($src_img);
}
// This function reads the extension of the file.
// It is used to determine if the file is an image by checking the extension.
function getExtension($str) {
$i = strrpos($str,".");
if (!$i) { return ""; }
$l = strlen($str) - $i;
$ext = substr($str,$i+1,$l);
return $ext;
}
// This variable is used as a flag. The value is initialized with 0 (meaning no error found)
//and it will be changed to 1 if an error occurs. If the error occures the file will not be uploaded.
$errors=0;
// checks if the form has been submitted
if(isset($_POST['Submit']))
{
$title = ($_POST['title']);
if ($title == '') // if title is not set
$title = '(No Title Provided)';// use (empty title) string
//reads the name of the file the user submitted for uploading
$image=$_FILES['image']['name'];
// if it is not empty
if ($image == '')
{
echo '<b> Error! </b> - You <b> must </b> select a file to upload before selecting the <b> "Upload image" </b> button. Please try again.';
$errors=1;
}
else
if ($image)
{
// get the original name of the file from the clients machine
$filename = stripslashes($_FILES['image']['name']);
// get the extension of the file in a lower case format
$extension = getExtension($filename);
$extension = strtolower($extension);
// if it is not a known extension, we will suppose it is an error, print an error message
//and will not upload the file, otherwise we continue
if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png"))
{
echo '<b> Error! </b> - The image that you attempted to upload is not in the correct format. The file format <b> must </b> be one of the following: <b> "jpg", "jpeg" </b> or <b> "png" </b>. Please try again.';
$errors=1;
}
else
{
// get the size of the image in bytes
// $_FILES[\'image\'][\'tmp_name\'] is the temporary filename of the file in which the uploaded file was stored on the server
$size=getimagesize($_FILES['image']['tmp_name']);
$sizekb=filesize($_FILES['image']['tmp_name']);
//compare the size with the maxim size we defined and print error if bigger
if ($sizekb > 1150000)
{
echo '<b> Error! </b> - The file that you are attempting to upload is greater than the prescribed <b> 1MB </b> limit. Please try again.';
$errors=1;
}
//we will give an unique name, for example the time in unix time format
$image_name=$title.'.'.$extension;
//the new name will be containing the full path where will be stored (images folder)
$newname="images/".$image_name;
$copied = copy($_FILES['image']['tmp_name'], $newname);
//we verify if the image has been uploaded, and print error instead
if (!$copied)
{
echo '<b> Error! </b> Your file has not been loaded';
$errors=1;
}
else
{
// the new thumbnail image will be placed in images/thumbs/ folder
$thumb_name='images/thumbs/'.$image_name;
// call the function that will create the thumbnail. The function will get as parameters
//the image name, the thumbnail name and the width and height desired for the thumbnail
$thumb=make_thumb($newname,$thumb_name,WIDTH,HEIGHT);
}} }}
//If no errors registred, print the success message and show the thumbnail image created
if(isset($_POST['Submit']) && !$errors)
{
echo '<br><b> Success! </b> - Your image has been uploaded</br>';
echo '<img src="'.$thumb_name.'">';
}
?>
<!-- next comes the form, you must set the enctype to "multipart/form-data" and use an input type "file" -->
<form name="newad" method="post" enctype="multipart/form-data" action="">
<table>
<tr><td><input type="text" name="title" ></td></tr>
<tr><td><input type="file" name="image" ></td></tr>
<tr><td><input name="Submit" type="submit" value="Upload image"></td></tr>
</table>
</form>
The problem I'm having is that I can't find a way of linking the 'location (parent)' record and the 'image (child)' record. Because the image upload is part of the parent record creation, the unique 'locationid' field hasn't been created.
I just wondered whether someone, perhaps with a lot more experience that I could suggest a way of overcoming this problem?
Many thanks and kind regards

Answer 1

Then uploading an image, save it's path on server to some storage (PHP session for example)
When saving your location, link images from session with created location and remove them from session (but not from server storage)
If action is cancelled - remove saved images from session and from server storage.
Also you need some garbage colection for the case if user just closing his browser without pressing any "cancel" buttons in yout UI.