Add a pwa:create:config command to bootstrap the configuration file

[Spomky]

Target branch: 1.6.x
Resolves issue # #84

• It is a Bug fix
• It is a New feature
• Breaks BC
• Includes Deprecations

Creating a PWA currently starts by copying config/packages/pwa.yaml from another project and tweaking the name and the description. This PR adds a pwa:create:config command that generates that file, either step by step or from options only.

Interactive mode

$ bin/console pwa:create:config

PWA Configuration Generator
===========================

 This command creates the configuration file of the bundle.
 Press Enter to accept the proposed value.

 Name of the application [Hacker News]:
 > HackerNews PWA
 Short name, displayed under the icon [HackerNews]:
 >
 Description of the application (optional):
 > A HackerNews implementation based on Symfony
 URL loaded when the application starts [/]:
 >
 Display mode [standalone]:
  [0] fullscreen
  [1] standalone
  [2] minimal-ui
  [3] browser
 >
 Theme color [#ffffff]:
 > #ff6600
 Background color [#ffffff]:
 >

 The icons and the favicons are generated from a single source image. It can be an Asset Mapper logical path (e.g. images/logo.svg) or a path to a file.

 Source image of the application (leave empty to skip):
 > images/logo.svg
 Generate the favicons from this image? (yes/no) [yes]:
 >

 Enable the service worker (offline support, caching, push notifications)? (yes/no) [yes]:
 >
 Path to the service worker source file [sw.js]:
 >

 [OK] The configuration file "config/packages/pwa.yaml" has been created.

Option mode

Every value has a dedicated option, so the command can be scripted:

bin/console pwa:create:config --no-interaction \
    --name="HackerNews PWA" \
    --description="A HackerNews implementation based on Symfony" \
    --icon=images/logo.svg

Both modes combine: interact() only asks for what was not passed as an option, and --no-interaction falls back to the defaults.

--dry-run writes the configuration on the standard output and nothing else, so it can be redirected:

bin/console pwa:create:config -n --dry-run > config/packages/pwa.yaml

Generated file

# See https://pwa.spomky-labs.com/ for the complete list of options.
pwa:
    image_processor: imagick
    manifest:
        enabled: true
        name: 'HackerNews PWA'
        short_name: HackerNews
        description: 'A HackerNews implementation based on Symfony'
        start_url: /
        display: standalone
        theme_color: '#ff6600'
        background_color: '#ffffff'
        icons:
            -
                src: images/logo.svg
                sizes: [48, 72, 96, 128, 144, 168, 192, 256, 512]
                format: png
    favicons:
        enabled: true
        default:
            src: images/logo.svg
            background_color: '#ffffff'
    serviceworker:
        enabled: true
        src: sw.js

Notes

• The default name is derived from the project directory, and the short name is truncated to 12 characters on a word boundary.
• The image processor is auto-detected, Imagick first as it is the only one able to read SVG sources. Requesting gd or imagick without the extension fails with an explicit message instead of writing a configuration that breaks the container.
• When the service worker is enabled, the empty source file Asset Mapper expects is created.
• An existing file is never overwritten without --force (or a confirmation in interactive mode).
• One of the tests feeds the generated file back into the bundle's Processor to guarantee it is actually loadable.

The documentation lives in another repository. installation.md still says a configuration file has to be written by hand — happy to open a companion PR there.

Options

Option	Description
--name	The name of the application
--short-name	The short name of the application, displayed under the icon
--description	The description of the application
--start-url	The URL loaded when the application starts
--display	The display mode (fullscreen, standalone, minimal-ui, browser)
--theme-color	The theme color of the application
--background-color	The background color of the application
--icon	The source image used to generate the icons and the favicons
--favicons / --no-favicons	Whether the favicons are generated
--serviceworker / --no-serviceworker	Whether the service worker is enabled
--serviceworker-src	The path to the service worker source file
--image-processor	The image processor used to generate the icons (imagick, gd, none)
--path	The configuration file to write
-f, --force	Overwrite the configuration file if it already exists
--dry-run	Display the configuration instead of writing it