SVG Sprites for Apostrophe

This module provides an Apostrophe piece type that manages and renders SVG sprites. Sprites can be imported from files in a website codebase or an external source via a URL.

SVG sprites must be generated by a separate process. The module does not provide functionality to build the sprite files. See below for sprite markup requirements.

Installation

To install the module, use the command line to run this command in an Apostrophe project's root directory:

npm install @apostrophecms/svg-sprite

Usage

Configure the SVG Sprite module in the app.js file:

require('apostrophe')({
  shortName: 'my-project',
  modules: {
    '@apostrophecms/svg-sprite': {}
  }
});

The SVG Sprites module should then be configured in its own index.js file with information about the sprite maps. Sprite files should be registered in the maps option, set to an array of configuration objects.

// modules/@apostrophecms/svg-sprite/index.js
module.exports = {
  options: {
    maps: [
      {
        label: 'Places Icons',
        name: 'places',
        file: 'svg/places.svg'
      },
      {
        label: 'Service Icons',
        name: 'services',
        file: 'svg/services.svg'
      }
    ]
  }
}

The configuration objects include:

• label: A clear label for the group of sprites.
• name: A string with no whitespace that is unique within the project.
• file: The location of the file. This may be a local file or a URL, as discussed below.

The sprites can be imported into Apostrophe as pieces by running the module's import task. This task will look for each registered sprite file and generate pieces (Apostrophe content) for each SVG. On the command line this task could be started from the project root with the following command:

node app @apostrophecms/svg-sprite:import

Sprite file location options

There are three options for registering SVG file locations:

1. Use a partial file path to a specific file, e.g., 'svg/places.svg'.
2. Use a partial file path with wild card symbols, e.g., 'svg/*-icons.svg'. See the Glob package documentation for acceptable patterns.
3. Use a URL for an externally hosted file, e.g., 'http://myfiles.net/svg/icons.svg'.

When using the partial file path options, the module will look for those files in its own public directory: modules/@apostrophecms/svg-sprite/public/. For example, 'svg/places.svg' would reference a file at modules/@apostrophecms/svg-sprite/public/svg/places.svg in the code base.

Sprite file markup

Sprite files use the SVG symbol element to include multiple SVG images within a single svg tag. See the CSS-Tricks guide for more information about how to construct and use these sprite files.

Requirements for this module include:

• Sprite maps must be formatted so that all <symbol>...<symbol/> elements are on the same node level. This simply means that symbol tags should not be nested within other symbol tags.
• symbol tags must have an id attribute, e.g., <symbol id="bicycle">...</symbol>.
• symbol tags can optionally have a title attribute that will be used as the imported piece's title field, e.g., <symbol title="Bicycle icon">...</symbol>

Here is an example of sprite file markup (with the path values abbeviated):

<svg xmlns="http://www.w3.org/2000/svg">
    <symbol width="24" height="24" viewBox="0 0 24 24" id="coffee_cup" >
        <path d="..." />
    </symbol>
    <symbol width="24" height="24" viewBox="0 0 24 24" id="bicycle" >
        <path d="..." />
    </symbol>
</svg>

Using SVG sprite pieces

The primary properties we use to reference individual SVG symbols are:

• file: The file path or URL to the full sprite map. This file still includes all symbols that were part of that original map file.
• svgId: The id property of the individual SVG symbol. We have to use this in combination with the file path to get a specific symbol.
• map: The map name property can be used to quickly find one of the sprite maps that were configured in the module's maps array.

HTML markup using an individual SVG symbol might look like the example below. The example uses svgSprite as a reference to the individual piece content. A project might reference sprite pieces using a relationship field, for example.

<svg>
  <use xlink:href="{{ svgSprite.file }}#{{ svgSprite.id }}"></use>
</svg>