YII图像缓存

Question

I am using IWI extension to cache image at time of display in yii framework . It's working fine but the problem is when I am updating a image the the past cache file and folder exists. Please help me to delete those past cache folder after update image.

Edit:

$img = $image_name[0]['image_name']; 
$p = 'images/'.$img;
$newpath = Yii::app()->iwi->load($p)->resize(100,300,Image::AUTO)->cache();
$newpath = explode('=',$newpath); ?> 
Image : <br/><br/> 
<?php echo CHtml::image($newpath[1],"image"); ?> 
<div class="row">
<?php echo $form->labelEx($model, 'image'); ?>
<?php echo $form->fileField($model, 'image'); ?>
<?php echo $form->error($model, 'image'); ?>
</div>

When i am updating a particular picture. Say I am updating a image whose id on the table is 1.the new picture is updating with new cache folders and previous cache folders exists.

Answer 1

Ok I had a look at the IwI extension and I think I understand what it is you ask.

Unfortunately you can't achieve this out of the box. Iwi uses a caching id with the last modified date. This means that changing an image creates a new cached file/folder rather than being replaced based on a dependency rule.

I think the best option would be to extend Iwi and then override the cache() method (preferably using Yii's caching)

Here's an untested example:

Extend Iwi class : This is very basicc and may not cover all your cases (ie: overwriting a file with another different file. Some of this is redundant but I did it so it was clear)

class MyIwi extends Iwi
{
    public function cache()
    {
        if (!isset($this->image["file"])) {
            return false;
        } 
        $cacheFolder = YiiBase::getPathOfAlias('webroot.images.site.cache');   
        $imagePath = $this->image["file"];
        $info = pathinfo($imagePath);


        //create unique ID (filename for cached image) using actions and path. then serialize and hash it.
        $needle = $this->actions;
        array_unshift($needle, $imagePath);
        $cachedFilePath = $cacheFolder."/".md5(json_encode($needle)).".".$info["extension"];

        //if cache file doesn't exist or is older than file then cache 
        if(  
           $this->createOrNone() //did not look into this, keeping because it was in original method
           &&
           (!file_exists($cachedFilePath)
           || 
           filetime($imagePath) > filetime($cachedFilePath))
        )
            $this->save($cachedFilePath);
        return Yii::app()->createUrl($cachedFilePath);
    }

}

Hopefully that will set you on the right track. Good luck