Victor - Ruby SVG Image Builder
Victor is a direct Ruby-to-SVG builder. All method calls are converted directly to SVG elements.
Table of Contents
- Install
- Examples
- Usage
- Composite SVG
- Saving the Output
- SVG Templates
- CSS
- Tagless Elements
- XML Encoding
- Using with Rails
- Related Projects
Install
$ gem install victor
Or with bundler:
gem 'victor'
Examples
require 'victor'
svg = Victor::SVG.new width: 140, height: 100, style: { background: '#ddd' }
svg.build do
rect x: 10, y: 10, width: 120, height: 80, rx: 10, fill: '#666'
circle cx: 50, cy: 50, r: 30, fill: 'yellow'
circle cx: 58, cy: 32, r: 4, fill: 'black'
polygon points: %w[45,50 80,30 80,70], fill: '#666'
3.times do |i|
x = 80 + i*18
circle cx: x, cy: 50, r: 4, fill: 'yellow'
end
end
svg.save 'pacman'
Output:
See the examples folder for several ruby scripts and their SVG output.
Usage
Initialize your SVG image:
require 'victor'
svg = Victor::SVG.new
Any option you provide to SVG.new
will be added as an attribute to the
main <svg>
element. By default, height
and width
are set to 100%.
svg = Victor::SVG.new width: '100%', height: '100%'
# same as just Victor::SVG.new
svg = Victor::SVG.new width: '100%', height: '100%', viewBox: "0 0 200 100"
Victor uses a single method (element
) to generate all SVG elements:
svg.element :rect, x: 2, y: 2, width: 200, height: 200
# => <rect x="2" y="2" width="200" height="200"/>
But you can omit it. Calls to any other method, will be delegated to the
element
method, so normal usage looks more like this:
svg.rect x: 2, y: 2, width: 200, height: 200
# => <rect x="2" y="2" width="200" height="200"/>
In other words, these are the same:
svg.element :anything, option: 'value'
svg.anything option: 'value'
You can use the build
method, to generate the SVG with a block
svg.build do
rect x: 0, y: 0, width: 100, height: 100, fill: '#ccc'
rect x: 20, y: 20, width: 60, height: 60, fill: '#f99'
end
If the value of an attribute is a hash, it will be converted to a style-compatible string:
svg.rect x: 0, y: 0, width: 100, height: 100, style: { stroke: '#ccc', fill: 'red' }
# => <rect x=0 y=0 width=100 height=100 style="stroke:#ccc; fill:red"/>
If the value of an attribute is an array, it will be converted to a space delimited string:
svg.path d: ['M', 150, 0, 'L', 75, 200, 'L', 225, 200, 'Z']
# => <path d="M 159 9 L 75 200 L 225 200 Z"/>
For SVG elements that have an inner content - such as text - simply pass it as the first argument:
svg.text "Victor", x: 40, y: 50
# => <text x="40" y="50">Victor</text>
You can also nest elements with blocks:
svg.build do
g font_size: 30, font_family: 'arial', fill: 'white' do
text "Scalable Victor Graphics", x: 40, y: 50
end
end
# => <g font-size="30" font-family="arial" fill="white">
# <text x="40" y="50">Scalable Victor Graphics</text>
# </g>
Underscores in attribute names are converted to dashes:
svg.text "Victor", x: 40, y: 50, font_family: 'arial', font_weight: 'bold', font_size: 40
# => <text x="40" y="50" font-family="arial" font-weight="bold" font-size="40">
# Victor
# </text>
Composite SVG
Victor also supports the abiliy to combine several smaller SVG objects into
one using the <<
operator or the #append
method.
This operator expects to receive any object that responds to #to_s
(can be another SVG
object).
require 'victor'
include Victor
# Create a reusable SVG object
frame = SVG.new
frame.rect x: 0, y: 0, width: 100, height: 100, fill: '#336'
frame.rect x: 10, y: 10, width: 80, height: 80, fill: '#fff'
# ... and another
troll = SVG.new
troll.circle cx: 50, cy: 60, r: 24, fill: 'yellow'
troll.polygon points: %w[24,50 50,14 76,54], fill: 'red'
# Combine objects into a single image
svg = SVG.new viewBox: '0 0 100 100'
svg << frame
svg << troll
# ... and save it
svg.save 'framed-troll'
Output:
These two calls are identical:
svg << other
svg.append other
Another approach to a more modular SVG composition, would be to subclass
Victor::SVG
.
See the composite svg example or the subclassing example for more details.
Saving the Output
Generate the full SVG to a string with render
:
result = svg.render
Or, save it to a file with save
:
svg.save 'filename'
# the '.svg' extension is optional
SVG Templates
The :default
SVG template is designed to be a full XML document (i.e.,
a standalone SVG image). If you wish to use the output as an SVG element
inside HTML, you can change the SVG template:
svg = Victor::SVG.new template: :html
# accepts :html, :minimal, :default or a filename
You can also point it to any other template file:
svg = Victor::SVG.new template: 'path/to/template.svg'
See the templates folder for an understanding of how templates are structured.
CSS
To add a CSS to your SVG, simply use the css
command inside your build
block, like this:
svg = Victor::SVG.new
svg.build do
css['.main'] = {
stroke: "green",
stroke_width: 2,
fill: "yellow"
}
circle cx: 35, cy: 35, r: 20, class: 'main'
end
You can also set CSS by providing a hash:
svg.css = {
'.bar': {
fill: '#666',
stroke: '#fff',
stroke_width: 1
},
'.negative': {
fill: '#f66'
},
'.positive': {
fill: '#6f6'
}
}
Underscore characters will be converted to dashes (stroke_width
becomes
stroke-width
).
If you need to add CSS statements , like @import
, use the following syntax:
css['@import'] = [
"url('https://fonts.googleapis.com/css?family=Audiowide')",
"url('https://fonts.googleapis.com/css?family=Pacifico')"
]
When the value of the CSS attribute is an array, Victor will simply use
the values of the array and prefix each of them with the key, so the above
will result in two @import url(...)
rows.
See the custom fonts example.
Tagless Elements
Using underscore (_
) as the element name will simply add the value to the
generated SVG, without any surrounding element. This is designed to allow
generating something like this:
<text>
You are
<tspan font-weight="bold">not</tspan>
a banana
</text>
using this Ruby code:
svg.build do
text do
_ 'You are'
tspan 'not', font_weight: "bold"
_ 'a banana'
end
end
See the targless elements example.
XML Encoding
Plain text values are encoded automatically:
svg.build do
text "Ben & Jerry's"
end
# <text>Ben & Jerry's</text>
If you need to use the raw, unencoded string, add !
to the element's name:
svg.build do
text! "Ben & Jerry's"
end
# <text>Ben & Jerry's</text>
See the xml encoding example.
Using with Rails
See the example_rails folder.
Related Projects
Icodi is a Ruby gem that uses Victor to generate consistent random icon images, similar to GitHub's identicon.