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

VERSION
Version 1.13, 28 October 2001 the section on "animate", the section on "cdata", the section on "CDATA", the section on "circle", the section on "defs", the section on "desc", the section on "ellipse", the section on "fe", the section on "get_path", the section on "group", the section on "image", the section on "line", the section on "mouseaction", the section on "new", the section on "path", the section on "polygon", the section on "polyline", the section on "rectangle (alias: rect)", the section on "script", the section on "style", the section on "text", the section on "title", the section on "use", the section on "xmlify (alias: to_xml render)" #!/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 ); 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: The the section on "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: A complete SVG document with its own associated DTD. A namespace for the SVG elements may be optionally specified. 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 the section on "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 the section on "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" ); Ronan Oger, ronan@roasp.com perl(1), L<SVG::Utils>, http://roasp.com/ http://www.w3c.org/Graphics/SVG/ 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 the section on "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 the section on "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 the section on "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 the section on "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: the section on "polyline", the section on "path", the section on "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 the section on "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 the section on "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 the section on "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: the section on "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">.

CDATA
$script = $svg->script(); $script->CDATA($text); Generates a <![CDATA[ ... ]]> tag with the contents of $text rendered exactly as supplied. 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: my $text = qq§ var SVGDoc; var groups = new Array(); var last_group; /***** * * init * * Find this SVG's document element * Define members of each group by id * *****/ function init(e) { SVGDoc = e.getTarget().getOwnerDocument(); append_group(1, 4, 6); // group 0 append_group(5, 4, 3); // group 1 append_group(2, 3); // group 2 }§; $svg->script()->CDATA($text); Result: E<lt>script E<gt> <gt>![CDATA[ var SVGDoc; var groups = new Array(); var last_group; /***** * * init * * Find this SVG's document element * Define members of each group by id * *****/ function init(e) { SVGDoc = e.getTarget().getOwnerDocument(); append_group(1, 4, 6); // group 0 append_group(5, 4, 3); // group 1 append_group(2, 3); // group 2 } ]]E<gt> SEE ALSO: L<"cdata">, L<"script">.

filter
$tag = $svg->filter(%attributes) Generate a filter. Filter elements contain the section on "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: the section on "fe".

fe
$tag = $svg->fe(-type=>'type', %attributes) Generate a filter sub-element. Must be a child of a the section on "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: SEE ALSO: the section on "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 the section on "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" ); The following elements are generically supported by SVG: See e.g. the section on "pattern" for an example of the use of these methods.