wordpress – Unique Scenario – get attachment ID by URL

I have encountered a quit unique scenario where I have an IMAGE url but not the ID of an unattached attachment (I know it sounds strange – but in wordpress terminology it is correct 🙂 ).

I am engaging the wordpress attachment upload form in a plugin, where a user can upload an image . he then clicks the “insert into post” button which populates the $options field. (standard procedure)

I then need the ID of that image.
The thing is that most of the functions of wordpress need an ID to work.

I can retrieve the ID of that image with a code like this :

$image_src = $options['upload_image'] ; // the options field in the plugin that holds the image URL


    $postid_img  = $wpdb->get_var(
        "SELECT ID FROM $wpdb->posts 
         WHERE guid = '$image_src' 
         AND post_type='attachment' LIMIT 1");

Now $postid_img is in fact the ID .

So where is the problem ?

The problem is that this code works perfectly only if the chosen image size is the FULL image size .
whenever the URL has intermediate image sizes, (e.g. – the image name , and hence the URL is with a surfixed size like ImageName -123×4500.jpg) – the above function will return 0.

Most of the wordpress attachment related functions (like get_intermediate_size() , or get_attachment_url() or many others ) need the ID as a parameter. but I do not have the ID at this stage of the function.

I even tried a little unknown function called url_to_postid( $url ) – which also fails.

I know that theoretically I could remove all the other sizes from the form, but it is a “hack” – not a solution – especially when we are inside a plugin that might need to co-exist with other plugins .

So how can I get the ID (of the “FULL” image) , based on a “custom” image URL with an Unknown ID , which is also unattached (not to post, page) at that moment ?

(Note that all the solutions which involve a post object or a custom query (which is not direct sql) will probably fail because at this point – the image is not attached to nothing – even if uploaded .)

EDIT I

(Note 2 – all string manipulations on the URL like trimming/regex etc, will be too dangerous to engage . if I will rely on the resolution part (e.g. 300×300) – I can never know what it will be , 4digitx4digit, 3×4 etc.. if I rely on the “-” character , there is no guarentee it will not appear in the image name itself.)

EDIT II UPDATE I –

I found a Hack to “resolve” this problem. I write “resolve” becasue it will work in MY SPECIFIC CASE , but not in all cases . (thanks to kovshenin on #wordpress IRC who pinted me in the right direction)

I changed the jQuery code of that updates the input field from :

window.send_to_editor = function(html) {
    imgurl = jQuery('img',html).attr('src');
    jQuery('#upload_image').val(imgurl);
    tb_remove();
    }

to :

window.send_to_editor = function(html) {
       var attachment_id = 0;
       var classes = jQuery('img',html).attr('class').match(/wp-image-([0-9]+)/); // regex to "hijack" the class name (which is the ID)
       if ( classes[1] )
        attachment_id = classes[1];
            imgurl = jQuery('img',html).attr('src');
            jQuery('#upload_image').val(attachment_id); // assign att id.
           tb_remove();
};

What this code does is actually take a CLASS name from the upload form (which has the ID in it ) and populate the input field with the right ID instead of the URL.

This is “hackish” at best – and not a solution for all situations. But in my specific scenario – it works .

Now – the interesting fact is that if this CLASS name in the form contains the ID – there MUST be a way to get it . it exists there – therefor something (a hook / filter / variable ) must be there for me to grab – but what and where – I do not know , and still did not find out .

The solution that @biziclop has suggested seems is the a right one – but for some reason it does not work on my code . Maybe some small thing must be changed there . (see update II)

Someone suggested to use backup_sizes instead of _wp_attachment_metadata with the same approach – but still nada .

If anyone has the answers – please post . I can not believe there is no way to get it (especially when it EXISTS on the form code like class-postID 🙂

UPDATE II –

@biziclop solution is working great .
I missed out the simple fact that my tables do not have the default renaming – hence the NULL array return when using his code “as-is”. (that and the stupid idea of trying to progress without the DEBUG mode on 🙂 )

SO thanks again !

All the above (and below) solutions would work.

One thing I am still curious about is the above mentioned classes in the upload form. If they are generated with the right ID (class-ID) there must be a way to get them with a simple hook/filter .. but I guess that would be for a later time .