jgan / victor

Ruby SVG Image Builder

Victor - Ruby SVG Image Builder

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Victor is a direct Ruby-to-SVG builder. All method calls are converted directly to SVG elements.

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Table of Contents

• Install
• Examples
• Usage
• Features
  • Composite SVG
  • Saving the Output
  • SVG Templates
  • CSS
  • Tagless Elements
  • XML Encoding
  • DSL Syntax
• Using with Rails
• Related Projects
• Contributing / Support

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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"

As an alternative, you can set the root SVG attributes using the setup method:

require 'victor'
svg = Victor::SVG.new
svg.setup width: 200, height: 150

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>

Features

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 &amp; 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.

DSL Syntax

Victor supports another a cleaner DSL-like syntax. To use it, simply require 'victor/script'.

Once required, you have access to:

• svg - returns an instance of Victor::SVG
• All the methods that are available on the SVG object, are included at the root level.

For example:

require 'victor/script'

setup width: 100, height: 100

build do
  circle cx: 50, cy: 50, r: 30, fill: "yellow"
end

puts render
save 'output.svg'

See the dsl example.

Using with Rails

See the example_rails folder.

Related Projects

victor-cli

A command line utility that generates Victor Ruby code from SVG code.

victor-opal

A Victor playground that works in the browser.

Icodi

A Ruby gem that uses Victor to generate consistent random icon images, similar to GitHub's identicon.

Contributing / Support

If you experience any issue, have a question or a suggestion, or if you wish to contribute, feel free to open an issue.

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