NAME

SVG - Perl extension for generating Scalable Vector Graphics (SVG) documents

VERSION

Version 1.12, 18 October 2001

METHODS

"animate", "cdata", "circle", "defs", "desc", "ellipse", "fe", "get_path", "group", "image", "line", "mouseaction", "new", "path", "polygon", "polyline", "rectangle (alias: rect)", "script", "style", "text", "title", "use", "xmlify (alias: to_xml render)"

SYNOPSIS

#!/usr/bin/perl -w
use strict;
use SVG;

# create an SVG object
my $svg= SVG->new(width=>200,height=>200);

# use explicit element constructor to generate a group element
my $y=$svg->group(
    id    => 'group_y',
    style => { stroke=>'red', fill=>'green' }
);

# add a circle to the group
$y->circle(cx=>100, cy=>100, r=>50, id=>'circle_in_group_y');

# or, use the generic 'tag' method to generate a group element by name
my $z=$svg->tag('g',
                id    => 'group_z',
                style => {
                    stroke => 'rgb(100,200,50)',
                    fill   => 'rgb(10,100,150)'
                }
            );

# create and add a circle using the generic 'tag' method
$z->tag('circle', cx=>50, cy=>50, r=>100, id=>'circle_in_group_z');

# create an anchor on a rectangle within a group within the group z
my $k = $z->anchor(
    id      => 'anchor_k',
    -href   => 'http://test.hackmare.com/',
    -target => 'new_window_0'
)->rectangle(
    x     => 20, y      => 50,
    width => 20, height => 30,
    rx    => 10, ry     => 5,
    id    => 'rect_k_in_anchor_k_in_group_z'
);

# now render the SVG object, implicitly use svg namespace
print $svg->xmlify;

# or, explicitly use svg namespace and generate a document with its own DTD
print $svg->xmlify(-namespace=>'svg');

# or, explicitly use svg namespace and generate an in-line docunent
print $svg->xmlify(
    -namespace => "svg",
    -ns_url    => "http://www.w3.org/2000/svg", # SVG namespace
    -xmlns     => "http://roasp.com/",          # Document namespace
    -inline   => 1
);

DESCRIPTION

SVG is a 100% Perl module which generates a nested data structure containing the DOM representation of an SVG (Scalable Vector Graphics) image. Using SVG, you can generate SVG objects, embed other SVG instances into it, access the DOM object, create and access javascript, and generate SMIL animation content.

General Steps to generating an SVG document

Generating SVG is a simple three step process:

1 The first step is to construct a new SVG object with "new".
2 The second step is to call element constructors to create SVG elements. Examples of element constructors are "circle" and "path".
3 The third and last step is to render the SVG object into XML using the "xmlify" method.

The "xmlify" method takes a number of optional arguments that control how SVG renders the object into XML, and in particular determine whether a stand-alone SVG document or an inline SVG document fragment is generated:

-stand-alone

A complete SVG document with its own associated DTD. A namespace for the SVG elements may be optionally specified.

-in-line

An in-line SVG document fragment with no DTD that be embedded within other XML content. As with stand-alone documents, an alternate namespace may be specified.

No XML content is generated until the third step is reached. Up until this point, all constructed element definitions reside in a DOM-like data structure from which they can be accessed and modified.

EXPORTS

None. However, SVG permits both options and additional element methods to be specified in the import list. These options and elements are then available for all SVG instances that are created with the "new" constructor. For example, to change the indent string to two spaces per level:

use SVG qw(-indent => "  ");

With the exception of -auto, all options may also be specified to the "new" constructor. The currently supported options are:

-auto        enable autoloading of all unrecognised method calls (0)
-indent      the indent to use when rendering the SVG into XML ("\t")
-inline      whether the SVG is to be standalone or inlined (0)
-printerror  print SVG generation errors to standard error (1)
-raiseerror  die if a generation error is encountered (1)

SVG also allows additional element generation methods to be specified in the import list. For example to generate 'star' and 'planet' element methods:

use SVG qw(star planet);

or:

use SVG ("star","planet");

This will add 'star' to the list of elements supported by SVG.pm (but not of course other SVG parsers...). Alternatively the '-auto' option will allow any unknown method call to generate an element of the same name:

use SVG (-auto => 1, "star", "planet");

Any elements specified explicitly (as 'star' and 'planet' are here) are predeclared; other elements are defined as and when they are seen by Perl. Note that enabling '-auto' effectively disables compile-time syntax checking for valid method names.

Example:

use SVG (
    -auto       => 0,
    -indent     => "  ",
    -raiserror  => 0,
    -printerror => 1,
    "star", "planet", "moon"
);

AUTHOR

Ronan Oger, ronan@roasp.com

SEE ALSO

perl(1), L<SVG::Utils>,
http://roasp.com/
http://www.w3c.org/Graphics/SVG/

Methods

SVG provides both explicit and generic element constructor methods. Explicit generators are generally (with a few exceptions) named for the element they generate.

All element constructors take a hash of element attributes and options; element attributes such as 'id' are passed by name, while options for the method (such as the type of an element that supports multiple alternate forms) are passed preceded by a hyphen, e.g '-type'. Both types may be freely intermixed; see the "fe" method and code examples througout the documentation for more examples.

new (constructor)

$svg = SVG->new(%attributes)

Creates a new SVG object. Attributes of the root SVG element be passed as an optional list of key value pairs. Additionally, SVG options (prefixed with a hyphen) may be set on a per object basis:

Example:

my $svg1=new SVG;

my $svg2=new SVG(id => 'root_element');

my $svg3=new SVG(
    -printerror => 1,
    -raiseerror => 0,
    -indent     => '  ',
    -namespace => "mysvg",
    -ns_url    => "http://www.w3.org/2000/svg", # SVG namespace
    -xmlns     => "http://roasp.com/",          # Document namespace
    -inline   => 1
    id          => 'root_element'
    width       => 300,
    height      => 200,
);

Default SVG options may also be set in the import list. See "EXPORTS" above for more on the available options.

Furthermore, the following options:

-version
-encoding
-standalone
-namespace
-xmlns (inline)
-ns_url (inline)
-inline
-identifier
-dtd (standalone)

may also be set in xmlify, overriding any corresponding values set in the SVG->new declaration

xmlify (alias: to_xml render)

$xmlstring = $svg->xmlify(%attributes)

Returns xml representation of svg document.

XML Declaration

Name               Default Value
-version           '1.0'               
-encoding          'UTF-8'
-standalone        'yes'
-namespace         'svg'                - namespace for elements
-xmlns (inline)    'http://example.org' - see <parent> tag below
-ns_url (inline)   'the url of the xml' - see <parent> tag below
-inline           '0' - If '1', then this is an inline document.
-identifier        '-//W3C//DTD SVG 1.0//EN';
-dtd (standalone)  'http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd'

Parent tag:

<parent xmlns="[-xmlns]" xmlns:[-namespace]="[-ns_url]">

For example:

print $svg->xmlify(
    -namespace => "mysvg",
    -ns_url    => "http://www.w3.org/2000/svg", # SVG namespace
    -xmlns     => "http://roasp.com/",          # Document namespace
    -inline   => 1
);

Output:

<parent xmlns="http://roasp.com" xmlns:mysvg="http://www.w3.org/2000/svg">
<mysvg:svg>
   ...
</mysvg:svg>

tag (alias: element)

$tag = $svg->tag($name, %attributes)

Generic element generator. Creates the element named $name with the attributes specified in %attributes. This method is the basis of most of the explicit element generators.

Example:

my $tag = $svg->tag('g', transform=>'rotate(-45)');

anchor

$tag = $svg->anchor(%attributes)

Generate an anchor element. Anchors are put around objects to make them 'live' (i.e. clickable). It therefore requires a drawn object or group element as a child.

Example:

    # generate an anchor	
    $tag = $svg->anchor(
        -href=>'http://here.com/some/simpler/svg.svg'
    );
    # add a circle to the anchor. The circle can be clicked on.
    $tag->circle(cx=>10,cy=>10,r=>1);

    # more complex anchor with both URL and target
    $tag = $svg->anchor(
	      -href   => 'http://somewhere.org/some/other/page.html',
	      -target => 'new_window'
    );

circle

$tag = $svg->circle(%attributes)

Draw a circle at (cx,cy) with radius r.

Example:

my $tag = $svg->circlecx=>4, cy=>2, r=>1);

ellipse

$tag = $svg->ellipse(%attributes)

Draw an ellipse at (cx,cy) with radii rx,ry.

Example:

my $tag = $svg->ellipse(
    cx=>10, cy=>10,
    rx=>5, ry=>7,
    id=>'ellipse',
    style=>{
        'stroke'=>'red',
        'fill'=>'green',
        'stroke-width'=>'4',
        'stroke-opacity'=>'0.5',
        'fill-opacity'=>'0.2'
    }
);

rectangle (alias: rect)

$tag = $svg->rectangle(%attributes)

Draw a rectangle at (x,y) with width 'width' and height 'height' and side radii 'rx' and 'ry'.

Example:

$tag = $svg->rectangle(
    x=>10, y=>20,
    width=>4, height=>5,
    rx=>5.2, ry=>2.4,
    id=>'rect_1'
);

image

$tag = $svg->image(%attributes)

Draw an image at (x,y) with width 'width' and height 'height' linked to image resource '-href'. See also "use".

Example:

$tag = $svg->image(
    x=>100, y=>100,
    width=>300, height=>200,
    '-href'=>"image.png", #may also embed SVG, e.g. "image.svg"
    id=>'image_1'
);

Output:

<image xlink:href="image.png" x="100" y="100" width="300" height="200"/>

use

$tag = $svg->use(%attributes)

Retrieve the content from an entity within an SVG document and apply it at (x,y) with width 'width' and height 'height' linked to image resource '-href'.

Example:

$tag = $svg->use(
    x=>100, y=>100,
    width=>300, height=>200,
    '-href'=>"pic.svg#image_1",
    id=>'image_1'
);

Output:

<use xlink:href="pic.svg#image_1" x="100" y="100" width="300" height="200"/>

According to the SVG specification, the 'use' element in SVG can point to a single element within an external SVG file.

polygon

$tag = $svg->polygon(%attributes)

Draw an n-sided polygon with vertices at points defined by a string of the form 'x1,y1,x2,y2,x3,y3,... xy,yn'. The "get_path" method is provided as a convenience to generate a suitable string from coordinate data.

Example:

# a five-sided polygon
my $xv = [0,2,4,5,1];
my $yv = [0,0,2,7,5];

$points = $a->get_path(
    x=>$xv, y=>$yv,
    -type=>'polygon'
);

$c = $a->polygon(
    %$points,
    id=>'pgon1',
    style=>\%polygon_style
);

SEE ALSO:

"polyline", "path", "get_path".

polyline

$tag = $svg->polyline(%attributes)

Draw an n-point polyline with points defined by a string of the form 'x1,y1,x2,y2,x3,y3,... xy,yn'. The "get_path" method is provided as a convenience to generate a suitable string from coordinate data.

Example:

# a 10-pointsaw-tooth pattern
my $xv = [0,1,2,3,4,5,6,7,8,9];
my $yv = [0,1,0,1,0,1,0,1,0,1];

$points = $a->get_path(
    x=>$xv, y=>$yv,
    -type=>'polyline',
    -closed=>'true' #specify that the polyline is closed.
);

my $tag = $a->polyline (
    %$points,
    id=>'pline_1',
    style=>{
        'fill-opacity'=>0,
        'stroke-color'=>'rgb(250,123,23)'
    }
);

line

$tag = $svg->line(%attributes)

Draw a straight line between two points (x1,y1) and (x2,y2).

Example:

my $tag = $svg->line(
    id=>'l1',
    x1=>0, y1=>10,
    x2=>10, y2=>0
);

To draw multiple connected lines, use "polyline".

text

$text = $svg->text(%attributes)->cdata();

$text_path = $svg->text(-type=>'path'); $text_span = $text_path->text(-type=>'span')->cdata('A'); $text_span = $text_path->text(-type=>'span')->cdata('B'); $text_span = $text_path->text(-type=>'span')->cdata('C'); $text = $svg->text(%attributes,-cdata=>'textstring');

define the container for a text string to be drawn in the image.

Input: -type = path type (path | polyline | polygon) -type = text element type (path | span | normal [default])

Example:

my $text1 = $svg->text(
    id=>'l1', x=>10, y=>10
)->cdata('hello, world');

my $text2 = $svg->text(
    id=>'l1', x=>10, y=>10, -cdata=>'hello, world');

my $text = $svg->text(
    id=>'tp', x=>10, y=>10 -type=>path)
    ->text(id=>'ts' -type=>'span')
    ->cdata('hello, world');

SEE ALSO:

L<"desc">, L<"cdata">.

title

$tag = $svg->title(%attributes)

Generate the title of the image.

Example:

my $tag = $svg->title(id=>'root-title')->cdata('This is the title');

desc

$tag = $svg->desc(%attributes)

Generate the description of the image.

Example:

my $tag = $svg->desc(id=>'root-desc')->cdata('This is a description');

comment

$tag = $svg->comment(@comments)

Generate the description of the image.

Example:

my $tag = $svg->comment('comment 1','comment 2','comment 3');

script

$tag = $svg->script(%attributes)

Generate a script container for dynamic (client-side) scripting using ECMAscript, Javascript or other compatible scripting language.

Example:

my $tag = $svg->script(-type=>"text/ecmascript");

# populate the script tag with cdata
# be careful to manage the javascript line ends.
# qq|text| or qq§text§ where text is the script 
# works well for this.

$tag->cdata(qq|function d(){
    //simple display function
    for(cnt = 0; cnt < d.length; cnt++)
        document.write(d[cnt]);//end for loop
    document.write("<BR>");//write a line break
  }|
);

path

$tag = $svg->path(%attributes)

Draw a path element. The path vertices may be imputed as a parameter or calculated usingthe "get_path" method.

Example:

# a 10-pointsaw-tooth pattern drawn with a path definition
my $xv = [0,1,2,3,4,5,6,7,8,9];
my $yv = [0,1,0,1,0,1,0,1,0,1];

$points = $a->get_path(
    x => $xv,
    y => $yv,
    -type   => 'path',
    -closed => 'true'  #specify that the polyline is closed
);

$tag = $svg->path(
    %$points,
    id    => 'pline_1',
    style => {
        'fill-opacity' => 0,
        'fill-color'   => 'green',
        'stroke-color' => 'rgb(250,123,23)'
    }
);

SEE ALSO:

"get_path".

get_path

$path = $svg->get_path(%attributes)

Returns the text string of points correctly formatted to be incorporated into the multi-point SVG drawing object definitions (path, polyline, polygon)

Input: attributes including:

-type     = path type (path | polyline | polygon)
x         = reference to array of x coordinates
y         = reference to array of y coordinates

Output: a hash reference consisting of the following key-value pair:

points    = the appropriate points-definition string
-type     = path|polygon|polyline
-relative = 1 (define relative position rather than absolute position)
-closed   = 1 (close the curve - path and polygon only)

Example:

   #generate an open path definition for a path.
   my ($points,$p);
   $points = $svg->get_path(x=&gt\@x,y=&gt\@y,-relative=&gt1,-type=&gt'path');

   #add the path to the SVG document
   my $p = $svg->path(%$path, style=>\%style_definition);

   #generate an closed path definition for a a polyline.
   $points = $svg->get_path(
       x=>\@x,
       y=>\@y,
       -relative=>1,
       -type=>'polyline',
       -closed=>1
   ); # generate a closed path definition for a polyline

   # add the polyline to the SVG document
   $p = $svg->polyline(%$points, id=>'pline1');

Aliases: get_path set_path

animate

$tag = $svg->animate(%attributes)

Generate an SMIL animation tag. This is allowed within any nonempty tag. Refer\ to the W3C for detailed information on the subtleties of the animate SMIL commands.

Inputs: -method = Transform | Motion | Color

my $an_ellipse = $svg->ellipse(
    cx=>30,cy=>150,rx=>10,ry=>10,id=>'an_ellipse',
    stroke=>'rgb(130,220,70)',fill=>'rgb(30,20,50)'); 

$an_ellipse-> animate(
    attributeName=>"cx",values=>"20; 200; 20",dur=>"10s", repeatDur=>'indefinite');

$an_ellipse-> animate(
    attributeName=>"rx",values=>"10;30;20;100;50",
    dur=>"10s", repeatDur=>'indefinite');

$an_ellipse-> animate(
    attributeName=>"ry",values=>"30;50;10;20;70;150",
    dur=>"15s", repeatDur=>'indefinite');

$an_ellipse-> animate(
    attributeName=>"rx",values=>"30;75;10;100;20;20;150",
    dur=>"20s", repeatDur=>'indefinite');

$an_ellipse-> animate(
    attributeName=>"fill",values=>"red;green;blue;cyan;yellow",
    dur=>"5s", repeatDur=>'indefinite');

$an_ellipse-> animate(
    attributeName=>"fill-opacity",values=>"0;1;0.5;0.75;1",
    dur=>"20s",repeatDur=>'indefinite');

$an_ellipse-> animate(
    attributeName=>"stroke-width",values=>"1;3;2;10;5",
    dur=>"20s",repeatDur=>'indefinite');

group

$tag = $svg->group(%attributes)

Define a group of objects with common properties. groups can have style, animation, filters, transformations, and mouse actions assigned to them.

Example:

$tag = $svg->group(
    id        => 'xvs000248',
    style     => {
        'font'      => [ qw( Arial Helvetica sans ) ],
        'font-size' => 10,
        'fill'      => 'red',
    },
    transform => 'rotate(-45)'
);

defs

$tag = $svg->defs(%attributes)

define a definition segment. A Defs requires children when defined using SVG.pm Example:

$tag = $svg->defs(id  =>  'def_con_one',);

style

$svg->style(%styledef)

Sets/Adds style-definition for the following objects being created.

Style definitions apply to an object and all its children for all properties for which the value of the property is not redefined by the child.

mouseaction

$svg->mouseaction(%attributes)

Sets/Adds mouse action definitions for tag

$svg->attrib($name, $value)

Sets/Adds mouse action definitions.

$svg->attrib $name, $value

$svg->attrib $name, \@value

$svg->attrib $name, \%value

Sets/Replaces attributes for a tag.

cdata

$svg->cdata($text)

Sets cdata to $text. SVG.pm allows you to set cdata for any tag. If the tag is meant to be an empty tag, SVG.pm will not complain, but the rendering agent will fail. In the SVG DTD, cdata is generally only meant for adding text or script content.

Example:

$svg->text(
    style => {
        'font'      => 'Arial',
        'font-size' => 20
    })->cdata('SVG.pm is a perl module on CPAN!');

my $text = $svg->text(style=>{'font'=>'Arial','font-size'=>20});
$text->cdata('SVG.pm is a perl module on CPAN!');

Result:

E<lt>text style="font: Arial; font-size: 20" E<gt>SVG.pm is a perl module on CPAN!E<lt>/text E<gt>

SEE ALSO:

L<"desc">, L<"title">, L<"text">, L<"script">.

filter

$tag = $svg->filter(%attributes)

Generate a filter. Filter elements contain "fe" filter sub-elements.

Example:

my $filter = $svg->filter(
    filterUnits=>"objectBoundingBox",
    x=>"-10%",
    y=>"-10%",
    width=>"150%",
    height=>"150%",
    filterUnits=>'objectBoundingBox'
);

$filter->fe();

SEE ALSO:

"fe".

fe

$tag = $svg->fe(-type=>'type', %attributes)

Generate a filter sub-element. Must be a child of a "filter" element.

Example:

my $fe = $svg->fe(
    -type     => 'DiffuseLighting'  # required - element name omiting 'fe'
    id        => 'filter_1',
    style     => {
        'font'      => [ qw(Arial Helvetica sans) ],
        'font-size' => 10,
        'fill'      => 'red',
    },
    transform => 'rotate(-45)'
);

Note that the following filter elements are currently supported:

  • feBlend

  • feColorMatrix

  • feComponentTransfer

  • feComposite

  • feConvolveMatrix

  • feDiffuseLighting

  • feDisplacementMap

  • feDistantLight

  • feFlood

  • feFuncA

  • feFuncB

  • feFuncG

  • feFuncR

  • feGaussianBlur

  • feImage

  • feMerge

  • feMergeNode

  • feMorphology

  • feOffset

  • fePointLight

  • feSpecularLighting

  • feSpotLight

  • feTile

  • feTurbulence

SEE ALSO:

"filter".

pattern

$tag = $svg->pattern(%attributes)

Define a pattern for later reference by url.

Example:

my $pattern = $svg->pattern(
    id     => "Argyle_1",
    width  => "50",
    height => "50",
    patternUnits        => "userSpaceOnUse",
    patternContentUnits => "userSpaceOnUse"
);

set

$tag = $svg->set(%attributes)

Set a definition for an SVG object in one section, to be referenced in other sections as needed.

Example:

my $set = $svg->set(
    id     => "Argyle_1",
    width  => "50",
    height => "50",
    patternUnits        => "userSpaceOnUse",
    patternContentUnits => "userSpaceOnUse"
);

stop

$tag = $svg->stop(%attributes)

Define a stop boundary for "gradient"

Example:

my $pattern = $svg->stop(
    id     => "Argyle_1",
    width  => "50",
    height => "50",
    patternUnits        => "userSpaceOnUse",
    patternContentUnits => "userSpaceOnUse"
);

$tag = $svg->gradient(%attributes)

Define a color gradient. Can be of type linear or radial

Example:

my $gradient = $svg->gradient(
    -type => "linear",
    id    => "gradient_1"
);

GENERIC ELEMENT METHODS

The following elements are generically supported by SVG:

  • altGlyph

  • altGlyphDef

  • altGlyphItem

  • clipPath

  • color-profile

  • cursor

  • definition-src

  • font-face-format

  • font-face-name

  • font-face-src

  • font-face-url

  • foreignObject

  • glyph

  • glyphRef

  • hkern

  • marker

  • mask

  • metadata

  • missing-glyph

  • mpath

  • switch

  • symbol

  • tref

  • view

  • vkern

See e.g. "pattern" for an example of the use of these methods.

1 POD Error

The following errors were encountered while parsing the POD:

Around line 920:

Non-ASCII character seen before =encoding in 'qq§text§'. Assuming CP1252