Can I have Composer or something else download a Git repo as a dependency of my contrib module?

Question

I'm working on a module and there is a sub module for scanning barcodes that requires this, quagga.
Currently you have to manually download the library and put it into the libraries dir. If I add this as a dependency to the module you cannot install it without doing this first.

Can I have composer or something download a git repo to the libraries when installing the submodule?

Edit:
libraries.yml

form:
  version: VERSION
  css:
    layout:
      css/commerce_pos_barcode_scanning.css: {}
  js:
    js/commerce_pos_barcode_scanning.js: {}
  dependencies:
    - core/jquery
    - core/drupal
    - commerce_pos/quagga
quagga:
  remote: https://github.com/serratus/quaggaJS.git
  version: 1.0.0
  license:
    name: MIT
    url: https://github.com/serratus/quaggaJS/blob/master/LICENSE
    gpl-compatible: yes
  js:
    /libraries/webrtc/adapter-latest.js: {}
    /libraries/quagga/quagga.min.js: {}

install.yml

function commerce_pos_barcode_scanning_requirements($phase) {
  $requirements = [];
  if ($phase == 'install' || $phase == 'runtime') {
    $path = 'libraries/quagga/quagga.min.js';
    if (!file_exists($path)) {
      $requirements['commerce_pos_barcode_scanning'] = [
        'title' => t('POS Barcode Scanning'),
        'description' => t('To scan barcodes, you need to install the quagga JavaScript library. <a href="/modules/contrib/commerce_pos/modules/barcode_scanning/README.md">How To</a>'),
        'severity' => REQUIREMENT_WARNING,
      ];
    }
    else {
      $requirements['commerce_pos_barcode_scanning'] = [
        'title' => t('POS Barcode Scanning'),
        'severity' => REQUIREMENT_OK,
        'value' => t('quagga JavaScript library has been configured.'),
      ];
    }
  }

  return $requirements;
}

Answer 1

You can edit file composer.js

find "web/libraries/{$name}": ["type:drupal-library"], change to

"web/libraries/{$name}": [
                "type:drupal-library",
                "type:bower-asset",
                "type:npm-asset",
                "vendor:npm-asset",
                "vendor:bower-asset",

            ],

add repositories

{
            "type": "package",
            "package": {
                "name": "serratus/quaggaJS",
                "version": "0.12.1",
                "type": "drupal-library",
                "source": {
                    "url": "https://github.com/serratus/quaggaJS.git",
                    "type": "git",
                    "reference": "master"
                },
                "dist": {
                    "url": "https://github.com/serratus/quaggaJS/zipball/master/serratus-quaggaJS-v0.12.1-14-g862df88.zip",
                    "type": "zip"
                },
                "require": {
                    "composer/installers": "^1.0.20"
                }
            }
        }

and run composer require "serratus/quaggaJS"

Answer 2

To have this be done automatically people will simply configure their project's composer.json themselves. So I'd recommend to just explain one more time how this is supposed to be done via Composer on your project's page on drupal.org or in the documentation to your module.

• https://stackoverflow.com/q/43121292/2199525
• How to use Composer to install third party libraries
• How to require a JS library in a composer.json file

---

Another inadvisable approach would be to provided a Drush command to download the library. Like Semantic UI API does it. Browse their code on GitLab. The command has not been ported to D8 yet. But I think you'll get the idea. Probably worth looking at their 8.x-1.x branch as well. And see how they solved it in D8.

Below code is from 7.x-1.x. SEMANTIC_UI_DOWNLOAD_URL leads to a Zip file on GitHub.

  $args = func_get_args();
  if ($args[0]) {
    $path = $args[0];
  }
  else {
    //we have dependencies on libraries module so no need to check for that
    //TODO: any way to get path for libraries directory?
    //Just in case if it is site specific? e.g. sites/domain.com/libraries ?
    $path = drush_get_context('DRUSH_DRUPAL_ROOT') . '/sites/all/libraries/semantic_ui';
  }
  // Create the path if it does not exist yet. Added substr check for preventing 
  // any wrong attempts or hacks !
  if (substr($path, -11) == 'semantic_ui' && !is_dir($path)) {
    drush_mkdir($path);
  }
  if (is_dir($path . '/dist')) {
    drush_log(dt('Semantic Ui already present at @path. No download required.', array('@path' => $path)), 'ok');
  }
  elseif (drush_op('chdir', $path) &&
      drush_shell_exec('wget ' . SEMANTIC_UI_DOWNLOAD_URL . '  -O semantic_ui.zip') &&
      drush_shell_exec('unzip semantic_ui.zip') &&
      drush_shell_exec('rm -rf semantic_ui.zip') &&
      drush_shell_exec('mv Semantic-UI-master/dist/* .') &&
      drush_shell_exec('rm -rf Semantic-UI-master')) {
    drush_log(dt('The latest Semantic Ui library has been downloaded to @path', array('@path' => $path)), 'success');
  }
  else {
    drush_log(dt('Drush was unable to download the Semantic Ui library to @path', array('@path' => $path)), 'error');
  }