How can I make a snippet return an image?

Is there a way to force a snippet to change the content-type? I want to set the header to an image. I know you can do it with a resource. But I wanted to make a self contained snippet.

I am making a snippet called DIG (Dynamic Image Generator) from this script. http://dummyimage.com/

[[!DIG? &size=`520x300` &background=`618200` &foreground=`fff` &text=`This is a MODx image.`]]

I can get it to create the file on the file system, but that leaves orphaned images to build up over time.

Could you just use an empty template and have the snippet generate HTML to produce the image (and maybe the header)?

Quote from: BobRay at Oct 21, 2010, 11:58 PM

Could you just use an empty template and have the snippet generate HTML to produce the image (and maybe the header)?

$output = '<img src = "generator.php" etc.>';
return $output;

Sure, but I was just trying to make it a bit cleaner for someone else to use.

If your snippet is responsible for writing the image directly to the browser, you could have it execute the following at the end:



(obviously replacing image/jpeg with your image’s associated content type.

This will prevent MODx from over-ruling the content-type header.

I did the same thing not long ago (using GD to render a thumbnail of an image on-demand.)

Thanks Andy, but that still kinda kills it as a snippet. But thank you, it gave me an idea. I moved the image generation code to an external file and just have the snippet build the image url.

It works great. This is snippet is intended to be used as a placeholder for development and mockups, I would not use it on a live site, since it makes the image on the fly every time. I added iab standard banner sizes too.

BTW I used the most excellent Packman to make the transport package. I am sure the snippet could be improved and made the Revo way.

Ah I see what you’re doing. Mine works slightly differently - you place the snippet on a dedicated resource page (uncached as the snippet caches thumbnails itself) which has an empty template:



I can then call this page from anywhere in modx:



imageId is the ID of a static resource in my modx content tree. Width and height are obviously how big to make the image. thumbnail_resource_id is a system setting containing the ID of the dedicated resource page.

This creates an <img> tag like:



The ImageThumbnail snippet reads the GET parameters and writes the image directly to the browser, which displays it for the <img> tag.

@Andy -- Good idea. I might need to do something like that in the future.

I made the DIG snippet just for fun. I think it would be useful for mocking up a design for a client with placeholder images (like the feature Dreamweaver has).