Dynamically Update Manifest file based on image uploads in SilverStripe admin

问题

I'm new to HTML5's application cache, but am familiar with the basics of it. I'm working on a cache manifest file for a SilverStripe site that needs to be dynamically updated whenever the content manager uploads a new image. I understand that the images will be appended to the Manifest function below using a loop, but the part that I find to be a challenge is updating the date and version number every time. Would I need to have the date and version listed as variables? Or is that not possible considering the setup of the Manifest function?

 public function Manifest() {
      $static = <<<EOT
        CACHE MANIFEST
        # 2016-03-17 v6.0.0
        [manifest content]
      EOT;

       //Append any new image file that gets uploaded
       $static = $static . "\n" . "/test.html";

       $this->response->addHeader("Content-type", "text/cache-manifest");
       return $static;
    }

回答1:

When you change cached by manifest file, the manifest content does not change. However you must change the content to trigger update in a browser. In this case you update a comment. This comment can contain anything. The date and version is common practice, because they reflect the change. So all you need it to get most recent change date from File.LastEdited field.

来源：https://stackoverflow.com/questions/36084893/dynamically-update-manifest-file-based-on-image-uploads-in-silverstripe-admin