[pbs-devel] [PATCH proxmox v7 1/2] router: cli: add confirmation helper
Gabriel Goller
g.goller at proxmox.com
Mon Jun 3 10:43:10 CEST 2024
Add confirmation helper that outputs a prompt and lets the user
confirm or deny it.
Implemented to close #4763.
Co-authored-by: Thomas Lamprecht <t.lamprecht at proxmox.com>
Signed-off-by: Gabriel Goller <g.goller at proxmox.com>
---
proxmox-router/Cargo.toml | 1 +
proxmox-router/src/cli/mod.rs | 114 +++++++++++++++++++++++++++++++++-
2 files changed, 114 insertions(+), 1 deletion(-)
diff --git a/proxmox-router/Cargo.toml b/proxmox-router/Cargo.toml
index dcd71a40..0b9d361f 100644
--- a/proxmox-router/Cargo.toml
+++ b/proxmox-router/Cargo.toml
@@ -19,6 +19,7 @@ percent-encoding.workspace = true
serde_json.workspace = true
serde.workspace = true
unicode-width ="0.1.8"
+regex.workspace = true
# cli:
tokio = { workspace = true, features = [], optional = true }
diff --git a/proxmox-router/src/cli/mod.rs b/proxmox-router/src/cli/mod.rs
index 7df94ad9..78f08920 100644
--- a/proxmox-router/src/cli/mod.rs
+++ b/proxmox-router/src/cli/mod.rs
@@ -12,7 +12,12 @@
//! - Ability to create interactive commands (using ``rustyline``)
//! - Supports complex/nested commands
-use std::collections::HashMap;
+use std::{
+ collections::HashMap,
+ io::{self, Write},
+};
+
+use anyhow::{bail, Error};
use crate::ApiMethod;
@@ -61,6 +66,113 @@ pub fn init_cli_logger(env_var_name: &str, default_log_level: &str) {
.init();
}
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+/// Use for simple yes or no questions, where booleans can be confusing, especially if there's a
+/// default response to consider. The implementation provides query helper for the CLI.
+pub enum Confirmation {
+ Yes,
+ No,
+}
+
+impl Confirmation {
+ /// Get the formatted choice for the query prompt, with self being the highlighted (default)
+ /// one displayed as upper case.
+ pub fn default_choice_str(self) -> &'static str {
+ match self {
+ Self::Yes => "Y/n",
+ Self::No => "y/N",
+ }
+ }
+
+ /// Returns true if the answer is Yes
+ pub fn is_yes(self) -> bool {
+ self == Self::Yes
+ }
+
+ /// Returns true if the answer is No
+ pub fn is_no(self) -> bool {
+ self == Self::No
+ }
+
+ /// Parse an input string reference as yes or no confirmation.
+ ///
+ /// The input string is checked verbatim if it is exactly one of the single chars 'y', 'Y',
+ /// 'n', or 'N'. You must trim the string before calling, if needed, or use one of the query
+ /// helper functions.
+ ///
+ /// ```
+ /// use proxmox_router::cli::Confirmation;
+ ///
+ /// let answer = Confirmation::from_str("y");
+ /// assert!(answer.expect("valid").is_yes());
+ ///
+ /// let answer = Confirmation::from_str("N");
+ /// assert!(answer.expect("valid").is_no());
+ ///
+ /// let answer = Confirmation::from_str("bogus");
+ /// assert!(answer.is_err());
+ /// ```
+ pub fn from_str(input: &str) -> Result<Self, Error> {
+ match input.trim() {
+ "y" | "Y" => Ok(Self::Yes),
+ "n" | "N" => Ok(Self::No),
+ _ => bail!("unexpected choice '{input}'! Use 'y' or 'n'"),
+ }
+ }
+
+ /// Parse a input string reference as yes or no confirmation, allowing a fallback default
+ /// answer if the user enters an empty choice.
+ ///
+ /// The input string is checked verbatim if it is exactly one of the single chars 'y', 'Y',
+ /// 'n', or 'N'. The empty string maps to the default. You must trim the string before calling,
+ /// if needed, or use one of the query helper functions.
+ ///
+ /// ```
+ /// use proxmox_router::cli::Confirmation;
+ ///
+ /// let answer = Confirmation::from_str_with_default("", Confirmation::No);
+ /// assert!(answer.expect("valid").is_no());
+ ///
+ /// let answer = Confirmation::from_str_with_default("n", Confirmation::Yes);
+ /// assert!(answer.expect("valid").is_no());
+ ///
+ /// let answer = Confirmation::from_str_with_default("yes", Confirmation::Yes);
+ /// assert!(answer.is_err()); // full-word answer not allowed for now.
+ /// ```
+ pub fn from_str_with_default(input: &str, default: Self) -> Result<Self, Error> {
+ match input.trim() {
+ "y" | "Y" => Ok(Self::Yes),
+ "n" | "N" => Ok(Self::No),
+ "" => Ok(default),
+ _ => bail!("unexpected choice '{input}'! Use enter for default or use 'y' or 'n'"),
+ }
+ }
+
+ /// Print a query prompt with available yes no choices and returns the String the user enters.
+ fn read_line(query: &str, choices: &str) -> Result<String, io::Error> {
+ print!("{query} [{choices}]: ");
+
+ io::stdout().flush()?;
+ let stdin = io::stdin();
+ let mut line = String::new();
+ stdin.read_line(&mut line)?;
+ Ok(line)
+ }
+
+ /// Print a query prompt and parse the white-space trimmed answer using `from_str`.
+ pub fn query(query: &str) -> Result<Self, Error> {
+ let line = Self::read_line(query, "y/n")?;
+ Confirmation::from_str(line.trim())
+ }
+
+ /// Print a query prompt and parse the answer using `from_str_with_default`, falling back to the
+ /// default_answer if the user provided an empty string.
+ pub fn query_with_default(query: &str, default_answer: Self) -> Result<Self, Error> {
+ let line = Self::read_line(query, default_answer.default_choice_str())?;
+ Confirmation::from_str_with_default(line.trim(), default_answer)
+ }
+}
+
/// Define a simple CLI command.
pub struct CliCommand {
/// The Schema definition.
--
2.43.0
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