Rob Brown > Image-Empty-0.20 > Image::Empty

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Module Version: 0.20   Source  

NAME ^

Image::Empty - HTTP response helper for 1x1 empty GIFs or PNGs, for building tracking URLs.

VERSION ^

Version 0.20

SYNOPSIS ^

Create 1x1 empty/transparent GIFs or PNGs to use in tracking URLs without the hassle of actually creating and/or loading image data.

Such a basic and common scenario deserves a basic solution.

 use Image::Empty;
 
 my $gif = Image::Empty->gif;   # swap for png
 
 print $gif->render;            # HTTP headers and body

METHODS ^

Class Methods

gif

Returns an instance representing an empty GIF (43 bytes) for use in an HTTP response.

 my $gif = Image::Empty->gif;

png

Returns an instance representing an empty PNG (67 bytes) for use in an HTTP response.

 my $png = Image::Empty->png;

Instance Methods

render

The render method is used to set the HTTP headers and body.

 $gif->render;

With no arguments, returns a string.

Under a CGI environment this would generally be printed directly to STDOUT (ie, the browser).

Chaining methods together can give very concise and compact code.

 use Image::Empty;
 
 print Image::Empty->gif->render;

Remember that the render method returns the HTTP headers. The above 2 lines are all you need in a script.

Plack

If you are working with Plack, supply the Plack::Response object to the render method.

The finalized Plack::Response object is returned.

As a quick one-liner...

 my $app = sub {

         return Image::Empty->gif->render( Plack::Response->new );
 }

It is the same as doing...

 my $app = sub {
 
         my $gif = Image::Empty->gif;
 
         my $response = Plack::Response->new;
 
         $response->status(200);
 
         $response->content_type( $gif->type );
         $response->content_length( $gif->length );
 
         $response->header( 'Content-Disposition' => $gif->disposition . '; filename="' . $gif->filename . '"' );
 
         $response->body( $gif->content ); 
 
         return $response->finalize;
 }

Catalyst

If you are working with Catalyst, see Catalyst::View::Image::Empty.

Attributes

type

 $gif->type;

Returns the mime/type of the image for use in HTTP headers.

length

 $gif->length;

Returns the content length for use in HTTP headers.

disposition

 $gif->disposition;

Returns the content disposition for use in HTTP headers.

filename

 $gif->filename;

Returns the content filename for use in HTTP headers.

content

 $gif->content;

Returns the image data to send in the HTTP response body.

TODO ^

mod_perl support

AUTHOR ^

Rob Brown, <rob at intelcompute.com>

BUGS ^

Please report any bugs or feature requests to bug-image-empty at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Image-Empty. I will be notified, and then you will automatically be notified of progress on your bug as I make changes.

SUPPORT ^

You can find documentation for this module with the perldoc command.

    perldoc Image::Empty

You can also look for information at:

LICENSE AND COPYRIGHT ^

Copyright 2012 Rob Brown.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.

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