single command + shell in one CLI program

[Jan Nielsen]

Hi there,

I'd like to build a Spring Boot 2.3 CLI application with picocli as I described on Stackoverflow which run individual commands as well as a shell:

  manager -u <user> -p <pass> [list|create|delete] # run and exit
  manager -u <user> -p <pass> @script              # run and exit
  manager -u <user> -p <pass>                      # run shell

The first two work, but the shell does not when I follow the JLine3 example:

    https://github.com/remkop/picocli/blob/master/picocli-shell-jline3/

with PicocliCommands and PicocliJLineCompleter as Spring @Components but enabling the components disables the picocli functionality. I don't know, yet, what's happening but just wondering if there any known issues.

I'll setup repo for this sample in a bit -- but any ideas in the interim are greatly appreciated.

Cheers,

Jan

[Jan Nielsen]

Here's the repository:

    https://github.com/JanStureNielsen/manager-picocli

[Remko Popma]

Hi Jan,

Thank you for raising this.

It looks like you already found how to implement most of the requirements mentioned in the StackOverflow question. That is good!

I am not aware of any issues with combining JShell with Spring, but that could be simply because I never tried this combination.

Thank you for providing a link to a working example, that makes this conversation a lot easier.

I noticed that your repo has picocli-spring-boot-starter as a dependency, that is good.

However, the ApplicationRunner class instantiates the ConnectCommand directly.

To enable Spring dependency injection in the subcommands, please use the SpringPicocliFactory to instantiate the ConnectCommand.

The picocli-spring-boot-starter README has an example.

In the ConnectCommand#run method, the ShellCommand#main method is invoked.

This in turn means we instantiate the CliCommands object directly without going through Spring.

This is similar, we need to give Spring a chance to do dependency injection here.

One idea is to have an @Inject CliCommands field in ConnectCommand, as well as a @Inject IFactory field,

and pass these to the ShellCommand#main method, so that this method can use these objects to create a CommandLine to start the interactive shell.

I hope this helps,

Remko.

[Jan Nielsen]

Ahh -- thanks for those, Remko! The repository sample now works as I need. You can update to see the changes. It still does not feel quite right but it now has all the functional elements which is awesome! 

Thanks hugely for your help -- I'll tidy the sample up a bit more before taking more of your time with my questions.

Cheers,

Jan

[Remko Popma]

Great! Glad to hear you’re making good progress.
Please let me know if you get stuck or if you find anything where the documentation can be improved.

Remko.