Andy Wardley > Template-Toolkit-2.24 > Template::Plugin::Image

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Module Version: 1.21   Source   Latest Release: Template-Toolkit-2.25

NAME ^

Template::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

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