On Fri, 10 May 2002 10:52:31 +0100 (BST) Mark Fowler <[EMAIL PROTECTED]> wrote: > > The basic text support could be extended to allow for images to be > > overlayed on the text (or placed under the text), or stretch images > > similarly to how Enlightenment displays window manager themes. > > Hmm, yes. I have it so the image can be aligned in various ways. > It's not quite up to stretching it yet, but we shall see.
I'm not either, all my module supports currently is text. > > Essentially, arguments are passed using the PATH_INFO HTTP header. > > We want the browser to think this is an actual file, instead of a > > dynamically generated image, so that the browser is more inclined to > > cache the content. So, a typical query would be: > > > > http://localhost/genText/font=ArialBold;size=24;fgcolor=#ffffff; > > bgcolor=#000000;rotate=90;text=This+Is+The+Text > > This is indeed a key concept. More importantly I designed my schemes > so that they could actually be saved to disk with that filename. One > possible idea would be to place the image creation in an ErrorHandler > which returns the image and writes it to the correct location on disk. > Thus the next time the image is called the perl code is skipped all > together and the image is simply sucked off of the disk. I think > Randal did a column on something like this a while back. Yes, like I say in my caching section, I sort the arguments and then MD5 them, and thats the name of the file on disk. So /tmp/Imagecache/0/1/A/098FAD9 etc. I actually do this process in the URI Transformation phase. I intercept a request, check to see if the given arguments already has a cache entry on disk, and if so, I change $r->filename() to that location on disk. Otherwise, I generate it, and again point to that filename...I then let Apache serve the file. > > *) Configuration Files > > I was thinking of using a system accessible in the httpd.conf for the > apache module. I want to stay away from httpd.conf-based config files. Although great for most things, the configuration of different image styles can be very site-specific, so I wouldn't want to have to reboot every time someone makes a change. In addition to this, I would like image styles to be editable through my Content Management System; if it's based in the httpd.conf (or even an .htaccess file), that means I'm giving a customer access to the control of the webserver, and that makes the hair stand up on the back of my neck. Rather, I could define an XML configuration file, and use a directive in the httpd.conf (or .htaccess) to point to the relevant configuration file for that site/location. > > *) Caching Schemes > > I hadn't really considered caching systems. Sounds good. > > > Note: To prevent the filesystem from filling up, due to DoS attacks, > > it may be prudent to have a cron job periodically cull files that > > have the oldest access time. > > Or have the handler do it itself after it's returned an image. You'd > also want the handler to keep a scoreboard of how many images have > been generated in the last x minutes to stop generating for things > like runaway spiders (though OTOH, this could probably be better > handled by another module somewhere else in the chain) I'm trying to keep from tying up the httpd processes unnecessarily. I just want to generate an image, and then pass it off to apache as fast as possible. If I have to disk scan (or even maintain a scoreboard in memory), I'm not sure how that would affect performance. It might not be a bad idea to add a scoreboard, but I don't want it to have to do too much. > > Looking forward, I would like to be able to use this for more than > > just text. I'd like my customers to be able to select an image, set > > the maximum size, check a few boxes or radio buttons to say what > > formatting options they'd like, and the image is automagically > > resized without wasting disk space or taking a long time to > > download. > > Disk space cheap, CPU cycles expensive. Disk space cheap, CPU cycles expensive, web developer time *really* expensive. So, auto-generate, and load from disk cache. > > I'm sure there are plenty of other uses for this, but I'll leave it > > at this. > > I'm warey of creating a all too powerful module. It's taken me an age > to come up with an interface that I think (IMHO) that has a sensible > user interface. I wouldn't want to create something too powerful. Unfortunately for me, I need to add these fancy-dancy features. The reason I'm coming back to this module of mine is because I need to have background images behind text, semi-transparency of multi-layered images, and resizing/scaling of images with borders and shadows, etc. -- -man Michael A Nachbaur PGP Public Key at http://www.nachbaur.com/pgpkey.asc PGP Key fingerprint = 83DC 7C3A 3084 6A21 9A3F 801E D974 AFB4 BFD7 2B6F
