Template::Plugin::ImagUser Contributed Perl DocumentTemplate::Plugin::Image(3)NAMETemplate::Plugin::Image - Plugin access to image sizes
SYNOPSIS
[% USE Image(filename) %]
[% Image.width %]
[% Image.height %]
[% Image.size.join(', ') %]
[% Image.attr %]
[% Image.tag %]
DESCRIPTION
This plugin provides an interface to the Image::Info or Image::Size
modules for determining the size of image files.
You can specify the plugin name as either '"Image"' or '"image"'. The
plugin object created will then have the same name. The file name of
the image should be specified as a positional or named argument.
[% # all these are valid, take your pick %]
[% USE Image('foo.gif') %]
[% USE image('bar.gif') %]
[% USE Image 'ping.gif' %]
[% USE image(name='baz.gif') %]
[% USE Image name='pong.gif' %]
A "root" parameter can be used to specify the location of the image
file:
[% USE Image(root='/path/to/root', name='images/home.png') %]
# image path: /path/to/root/images/home.png
# img src: images/home.png
In cases where the image path and image url do not match up, specify
the file name directly:
[% USE Image(file='/path/to/home.png', name='/images/home.png') %]
The "alt" parameter can be used to specify an alternate name for the
image, for use in constructing an XHTML element (see the "tag()" method
below).
[% USE Image('home.png', alt="Home") %]
You can also provide an alternate name for an "Image" plugin object.
[% USE img1 = image 'foo.gif' %]
[% USE img2 = image 'bar.gif' %]
The "name" method returns the image file name.
[% img1.name %] # foo.gif
The "width" and "height" methods return the width and height of the
image, respectively. The "size" method returns a reference to a 2
element list containing the width and height.
[% USE image 'foo.gif' %]
width: [% image.width %]
height: [% image.height %]
size: [% image.size.join(', ') %]
The "modtime" method returns the modification time of the file in
question, suitable for use with the Date plugin, for example:
[% USE image 'foo.gif' %]
[% USE date %]
[% date.format(image.modtime, "%B, %e %Y") %]
The "attr" method returns the height and width as HTML/XML attributes.
[% USE image 'foo.gif' %]
[% image.attr %]
Typical output:
width="60" height="20"
The "tag" method returns a complete XHTML tag referencing the image.
[% USE image 'foo.gif' %]
[% image.tag %]
Typical output:
<img src="foo.gif" width="60" height="20" alt="" />
You can provide any additional attributes that should be added to the
XHTML tag.
[% USE image 'foo.gif' %]
[% image.tag(class="logo" alt="Logo") %]
Typical output:
<img src="foo.gif" width="60" height="20" alt="Logo" class="logo" />
Note that the "alt" attribute is mandatory in a strict XHTML "img"
element (even if it's empty) so it is always added even if you don't
explicitly provide a value for it. You can do so as an argument to the
"tag" method, as shown in the previous example, or as an argument
[% USE image('foo.gif', alt='Logo') %]
CATCHING ERRORS
If the image file cannot be found then the above methods will throw an
"Image" error. You can enclose calls to these methods in a
"TRY...CATCH" block to catch any potential errors.
[% TRY;
image.width;
CATCH;
error; # print error
END
%]
USING Image::Info
At run time, the plugin tries to load Image::Info in preference to
Image::Size. If Image::Info is found, then some additional methods are
available, in addition to "size", "width", "height", "attr", and "tag".
These additional methods are named after the elements that Image::Info
retrieves from the image itself. The types of methods available depend
on the type of image (see Image::Info for more details). These
additional methods will always include the following:
file_media_type
This is the MIME type that is appropriate for the given file format.
The corresponding value is a string like: ""image/png"" or
""image/jpeg"".
file_ext
The is the suggested file name extention for a file of the given file
format. The value is a 3 letter, lowercase string like ""png"",
""jpg"".
color_type
The value is a short string describing what kind of values the pixels
encode. The value can be one of the following:
Gray
GrayA
RGB
RGBA
CMYK
YCbCr
CIELab
These names can also be prefixed by ""Indexed-"" if the image is
composed of indexes into a palette. Of these, only ""Indexed-RGB"" is
likely to occur.
(It is similar to the TIFF field PhotometricInterpretation, but this
name was found to be too long, so we used the PNG inpired term
instead.)
resolution
The value of this field normally gives the physical size of the image
on screen or paper. When the unit specifier is missing then this field
denotes the squareness of pixels in the image.
The syntax of this field is:
<res> <unit>
<xres> "/" <yres> <unit>
<xres> "/" <yres>
The "<res>", "<xres>" and "<yres>" fields are numbers. The "<unit>" is
a string like "dpi", "dpm" or "dpcm" (denoting "dots per
inch/cm/meter).
SamplesPerPixel
This says how many channels there are in the image. For some image
formats this number might be higher than the number implied from the
"color_type".
BitsPerSample
This says how many bits are used to encode each of samples. The value
is a reference to an array containing numbers. The number of elements
in the array should be the same as "SamplesPerPixel".
Comment
Textual comments found in the file. The value is a reference to an
array if there are multiple comments found.
Interlace
If the image is interlaced, then this returns the interlace type.
Compression
This returns the name of the compression algorithm is used.
Gamma
A number indicating the gamma curve of the image (e.g. 2.2)
AUTHOR
Andy Wardley <abw@wardley.org> <http://wardley.org/>
COPYRIGHT
Copyright (C) 1996-2007 Andy Wardley. All Rights Reserved.
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
Template::Plugin, Image::Info
perl v5.14.3 2011-12-20 Template::Plugin::Image(3)
