Dividing $obj->width() output by 2?

[Chrisnaj]

Hello.

I'm not a PHP coder (more frontend dev) but I've been tasked with tweaking some PHP.

Specifically, the client wants to upload double-sized images but still get the image to display at the original size.

At the moment, when an image is uploaded (via a custom image manager) the width of the image is noted and an inline style is generated within a file called ajax_actions.php:

$obj = new Image($id);

<img src="'.$obj->src().'" title="'.$obj->artist().'" style="max-width:'.$obj->width().'px;"/>

The code I'm interested in is this:

style="max-width:'.$obj->width().'px;"

Is there any way of introducing a calculation to halve the size of the uploaded image into the empty brackets following width, something like: 

$obj->width(/2)

?

I can't, at the moment, do any tests on the file myself, so I'm looking for information as to how it should be done.

If I haven't supplied enough info please let me know.

Any help would be greatly appreciated!

 

 

[Barand]

Images tend to be uploaded once but download for display many times. Thus the most efficient method is to create a display-sized image when the file is uploaded and store both. When required for output, get the display-sized image instead of the original. This results in smaller files hence faster loads.

Edited July 16, 2018 by Barand

[Chrisnaj]

Hi Barand,

thanks for getting back so quickly.

Just wondering if you've got an answer to my specific question re dividing the image width in 2 using the code I quoted?

 

[Barand]

Not from the code you posted - a php line directly followed by an html line.

Can you post the relevant current "working" code so I can see it in context.

In your Image class, are src(),  artist() and width() really methods or are they properties?

[Chrisnaj]

Here it is (thanks!):

<?php
if(isset($_REQUEST['action'])){ $action = $_REQUEST['action']; } else { echo 'ERROR'; exit; }

if($action == 'MORE_IMAGES'){
    if(isset($_REQUEST['ids'])){ $ids = explode(',', $_REQUEST['ids']); } else { echo 'ERROR'; exit; }
    if(isset($_REQUEST['category'])){ $category = $_REQUEST['category']; } else { echo 'ERROR'; exit; }
    if(isset($_REQUEST['category_id'])){ $category_id = $_REQUEST['category_id']; } else { echo 'ERROR'; exit; }
    if(isset($_REQUEST['from'])){ $from = $_REQUEST['from']; } else { echo 'ERROR'; exit; }

    $list = new Images($category);
    $list->query_list($ids);

    $list->reset(); 
    $i = $from; 
    while(list($id, $obj) = $list->each()){     
        echo '<img id="thumbnail-'.$i++.'" class="thumbnail" src="'.$obj->tsrc().'" title="'.$obj->artist().'" data-id="'.$obj->id().'"/>';
    }
} else if($action == 'IMAGE_DATA'){
    if(isset($_REQUEST['id'])){ $id = $_REQUEST['id']; } else { echo 'ERROR'; exit; }
    
    $sql = '
        SELECT nb_artist.nb_artist_name as name, '.sql_clean_href('nb_artist.nb_artist_name').' as href 
        FROM nb_artist LEFT JOIN nb_image_artist USING (nb_artist_id) WHERE nb_image_id = "'.$id.'"
    ';
    $rows = $GLOBALS['IDB']->get_results($sql, ARRAY_A);
    $artist = '<a href="/'.$rows[0]['href'].'">'.$rows[0]['name'].'</a>';
    
    $data = '';
    $styles = new Styles();
    $sql = '
        SELECT nb_style.nb_style_name as name, '.sql_clean_href('nb_style.nb_style_name').' as href
        FROM nb_style LEFT JOIN nb_image_style USING (nb_style_id) WHERE nb_image_id = "'.$id.'"
    ';
    $rows = $GLOBALS['IDB']->get_results($sql, ARRAY_A);
    foreach($rows as $row){
        if($styles->exists_by_href($row['href'])){
            $data .= '<li><a href="/'.$row['href'].'">'.$row['name'].'</a></li>';
        }
    }

    $subjects = new Subjects();
    $sql = '
        SELECT nb_subject.nb_subject_name as name, '.sql_clean_href('nb_subject.nb_subject_name').' as href
        FROM nb_subject LEFT JOIN nb_image_subject USING (nb_subject_id) WHERE nb_image_id = "'.$id.'"
    ';
    $rows = $GLOBALS['IDB']->get_results($sql, ARRAY_A);
    foreach($rows as $row){
        if($subjects->exists_by_href($row['href'])){
            $data .= '<li><a href="/'.$row['href'].'">'.$row['name'].'</a></li>';
        }
    }
    $obj = new Image($id);
    echo '
    <img id="prev-image" src="/wp-content/themes/nb/css/bg/arrow-previous.png">
    <img id="next-image" src="/wp-content/themes/nb/css/bg/arrow-next.png">
    <figure>
        <img src="'.$obj->src().'" title="'.$obj->artist().'" style="max-width:'.$obj->width().'px;"/>
        <figcaption class="clearfix">© '.date('Y').' '.$artist.'</figcaption>
    </figure>
    <div class="keywords">
        <strong>See also</strong>
        <ul class="clearfix">'.$data.'</ul>
        <p id="logged-in-image-link">http://www.nbillustration.co.uk/image/'.$id.'/</p>
    </div>';
    
} else if($action == 'IMAGE_DATA_SHORT'){
    if(isset($_REQUEST['id'])){ $id = $_REQUEST['id']; } else { echo 'ERROR'; exit; }
    $obj = new Image($id);
    echo '
    <figure>
        <img src="'.$obj->src().'" title="'.$obj->artist().'" style="max-width:'.$obj->width().'px;"/>
        <figcaption class="clearfix">© '.date('Y').' '.$obj->artist().'</figcaption>
    </figure>';
    
}
?>

 

[Barand]

try

$halfwidth = $obj->width() / 2;

echo '<img src="'.$obj->src().'" title="'.$obj->artist().'" style="max-width:'.$halfwidth.'px;"/>';

 

Edited July 16, 2018 by Barand

[Chrisnaj]

Thank you very much for your help ?