# Esvg
Easly slip optimized, cached svgs into your workflow using standalone CLI or the simple Rails integration.
1. Converts a directory full of SVGs into a an optimized SVG using symbols for each file.
2. Build a Javascript file to inject SVGs into pages, so it's easily cacheable.
3. Offers Rails application helpers for placing icons in your views.
[](https://rubygems.org/gems/esvg)
[](https://travis-ci.org/imathis/esvg)
[](http://imathis.mit-license.org)
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'esvg'
```
And then execute:
$ bundle
Or install it yourself as:
$ gem install esvg
## Usage: Rails
Add `Esvg.precompile_assets` to your `config/initializers/assets.rb` to add build with `rake assets:precomile`.
Add SVG files to your `app/assets/svgs/` directory.
for example:
```
app/assets/svgs
- logo.svg
- share.svg
- thumbs-up.svg
```
### Inject SVG symbols
Add this to a page or layout where SVGs should be available
```
<%= embed_svgs %>
```
**During development:**
This will embed a `<script>` which will place svg symbols at the top of your site's `<body>` as soon as the DOM is ready, and after any Turbolinks page load events.
**In Production:**
The `embed_svgs` view helper will write a `javascript_include_tag` to include the script (rather than embeding it in the page).
When you run `rake assets:precompile` this script will be built to `public/assets/svgs-{fingerprint}.js` (and a gzipped version).
This allows browsers to cache the javascript files and reduce the weight of downloading svgs for each page.
### Placing an SVG
To place an SVG, use the `use_svg` vew helper. This helper will embed an SVG `use` tag which will reference the appropriate symbol. Here's how it works.
```
# Syntax: use_svg name, [options]
# Standard example
<%= use_svg 'logo' %>
# Output:
# <svg class="svg-symbol svg-logo"><use xlink:href="#svg-logo"/></svg>
# Add custom classnames
<%= use_svg 'share', class: 'disabled' %>
# Output:
# <svg class="svg-symbol svg-share disabled"><use xlink:href="#svg-share"/></svg>
# Add custom styles
<%= use_svg 'logo', style: 'fill: #c0ffee' %>
# Use presets (setup in config yaml)
<%= use_svg 'chevron', preset: 'icon' %>
# Use size classes (setup in config yaml)
<%= use_svg 'chevron', size: 'small' %>
# Output:
# <svg class="svg-symbol svg-logo" style="fill: #coffee;"><use xlink:href="#svg-logo"/></svg>
# Add title and desc tags for SVG accessibility.
<%= use_svg 'kitten', title: "Mr. Snuggles", desc: "A graphic of a cat snuggling a ball of yarn" %>
# Output:
# <svg class="icon kitten-icon"><use xlink:href="#kitten-icon"/>
# <title>Mr. Snuggles</title>
# <desc>A graphic of a cat snuggling a ball of yarn</desc>
# </svg>
# Provide fallback icon if an icon is missing (great for when you are generating icon names from code)
<%= use_svg 'missing', fallback: 'default' %>
```
## Usage: stand-alone CLI
```
# Syntax:
$ esvg PATH [options]
# Examples:
$ esvg # Read icons from current directory, write js to ./svgs.js
$ esvg icons # Read icons from 'icons' directory, write js to ./svgs.js
$ esvg --output build # Read icons from current directory, write js to build/svgs.js
$ esvg -c --config foo.yml # Read confguration from foo.yml (otherwise, defaults to esvg.yml, or config/esvg.yml)
```
## Configuration
If you're using esvg from the command line, configuration files are read from `./esvg.yml` or you can pass a path with the `--config` option to read the config file from elsewhere.
```
source: . # Where to find SVG icons (Rails defaults to app/assets/esvg)
build: . # Where to write build files
assets: . # Where to write asset files (builds for directories beginning in _)
tmp: . # Write temporary cache files (will write to #{dir}/.esvg-cache/
class: svg-symbol # All svgs with `use_svg` will have this base classname
namespace: svg # Namespace for symbol ids, e.g 'svg-logo'
namespace_before: true # Add namespace before, e.g. 'svg-logo', false would be 'logo-svg'
alias: # Add aliases for icon names
comment: chat # use "chat" to reference comment.svg
error: bad, broken # Use "bad" or "broken" to reference error.svg
presets: # Add named presets for setting common options
icon: # Passing option preset: 'icon' will set these defaults
height: 1em
class: icon
sizes: # Define size classes for easy assignment
small: # size classes override presets
height: 10px
medium:
height: 20px
```
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/imathis/esvg. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](contributor-covenant.org) code of conduct.
## License
The gem is available as open source under the terms of the [MIT License](http://opensource.org/licenses/MIT).