Argument that requires argument group?

[EnderNon]

this is my current setup:

use clap::{Args, Parser};

#[derive(Parser, Clone)]
#[command(version, about, long_about = None, arg_required_else_help(true))]
pub struct FrArgs {
    /// Flag to dump the packet data 
    #[arg(short, long)]
    #[arg(requires="DumpArgs")]
    #[clap(default_value_t = false)]
    pub dump: bool,
    #[command(flatten)]
    pub dumper: DumpArgs,

    #[arg(long)]
    #[clap(default_missing_value = "./log.txt", default_value = "")]
    pub log: String,
}

#[derive(Args, Clone)]
#[group(required = false, multiple = true)]
pub struct DumpArgs {
    /// Server address
    #[arg(short, long)]
    pub address: String,
    /// Minecraft email
    #[arg(short, long)]
    pub email: String,
}

What I'm trying to do is, make it so that if the argument dump is present, then the entire group DumpArgs (from the struct) is required too. However, it doesn't seem to work properly, it seems to think that the arguments in DumpArgs (address, email) are always required. I don't know how to fix this, help would be appreciated.

cargo run -- --log "test"
    Finished `dev` profile [optimized + debuginfo] target(s) in 0.13s
     Running `debug/respack-scraper --log test`
error: the following required arguments were not provided:
  --address <ADDRESS>
  --email <EMAIL>

Usage: respack-scraper --address <ADDRESS> --email <EMAIL> --log <LOG>

For more information, try '--help'.

[EnderNon]

Also changing the requires value to "dumper" (as in the struct variable name for the flattened group) seems to break it

    /// Flag to dump the packet data 
    #[arg(short, long)]
    #[arg(requires="dumper")]
    #[clap(default_value_t = false)]
    pub dump: bool,
    #[command(flatten)]
    pub dumper: DumpArgs,

cargo run -- --dump   
   Compiling respack-scraper v0.1.0 (/new2/git/respack-scraper)
    Finished `dev` profile [optimized + debuginfo] target(s) in 2.17s
     Running `debug/respack-scraper --dump`

thread 'main' panicked at /home/endernon/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/clap_builder-4.5.39/src/builder/debug_asserts.rs:149:13:
Command respack-scraper: Argument or group 'dumper' specified in 'requires*' for 'dump' does not exist
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

cargo run  -- -a "test" -e "test"  
    Finished `dev` profile [optimized + debuginfo] target(s) in 0.09s
     Running `debug/respack-scraper -a test -e 'test`

thread 'main' panicked at /home/endernon/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/clap_builder-4.5.39/src/builder/debug_asserts.rs:149:13:
Command respack-scraper: Argument or group 'dumper' specified in 'requires*' for 'dump' does not exist
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

cargo run  -- --dump -a "test" -e "test" 
    Finished `dev` profile [optimized + debuginfo] target(s) in 0.09s
     Running `debug/respack-scraper --dump -a test -e 'test'`

thread 'main' panicked at /home/endernon/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/clap_builder-4.5.39/src/builder/debug_asserts.rs:149:13:
Command respack-scraper: Argument or group 'dumper' specified in 'requires*' for 'dump' does not exist
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[epage]

You are likely running into a problem with your struct design. When populating dump, you are requiring a DumpArgs to be instantiated which requires every field to be specified.

The best option is likely

    #[command(flatten)]
-    pub dumper: DumpArgs,
+    pub dumper: Option<DumpArgs>,

[EnderNon]

You are likely running into a problem with your struct design. When populating dump, you are requiring a DumpArgs to be instantiated which requires every field to be specified.

The best option is likely

    #[command(flatten)]
-    pub dumper: DumpArgs,
+    pub dumper: Option<DumpArgs>,

Yes, that was it. I've got two new questions now.
(1) How can I make sure that dumper has either got everything filled or nothing filled? As in, either have both address and email or else have neither address nor email.
(2) Is there a way to signify in the help menu that address and email are part of the dump group?

  -d, --dump               Flag to dump the packet data
  -a, --address <ADDRESS>  Server address
  -e, --email <EMAIL>      Minecraft email

This is what it looks like right now. Does indenting exist so that it shows -a and -e (from DumpGroup) are only required for -d?

[epage]

(1) How can I make sure that dumper has either got everything filled or nothing filled? As in, either have both address and email or else have neither address nor email.

We don't have an "all or nothing" mode for groups.

Personally, I think I'd be more interested in us supporting a way to say that an option is required within one of its groups and for us, on clap v5, to change the meaning of a required field in clap_derive from being required at all to being required within the group. This would allow us to evolve things to be more group-centric and naturally have a way of expressing "all or nothing" just through the types (since all structs create a group).

Feel free to open an issue around this need.

(2) Is there a way to signify in the help menu that address and email are part of the dump group?

The main way I've handled this or recommended this is to use help_heading. #4589 would help.

[hydra]

I'm bumping into this today, I made a PR to an example repo to demonstrate a) the issue, b) the desired approach.

hydra/rust-examples#1

@epage would really appreciate it if you could put some effort into this for clap v5
@EnderNon did you open an issue for this need?

[EnderNon]

nah I just decided to make it into requiring you to supply a toml config, it's easier this way