Struct inquire::CustomType [−][src]
pub struct CustomType<'a, T> {
pub message: &'a str,
pub default: Option<(T, CustomTypeFormatter<'a, T>)>,
pub placeholder: Option<&'a str>,
pub help_message: Option<&'a str>,
pub formatter: CustomTypeFormatter<'a, T>,
pub parser: CustomTypeParser<'a, T>,
pub error_message: String,
pub render_config: &'a RenderConfig,
}
Expand description
Generic prompt suitable for when you need to parse the user input into a specific type, for example an f64
or a rust_decimal
, maybe even an uuid
.
This prompt has all of the validation, parsing and error handling features built-in to reduce as much boilerplaste as possible from your prompts. Its defaults are necessarily very simple in order to cover a large range of generic cases, for example a “Invalid input” error message.
You can customize as many aspects of this prompt as you like: prompt message, help message, default value, placeholder, value parser and value formatter.
Behavior
When initializing this prompt via the new()
method, some constraints on the return type T
are added to make sure we can apply a default parser and formatter to the prompt.
The default parser calls the str.parse
method, which means that T
must implement the FromStr
trait. When the parsing fails for any reason, a default error message “Invalid input” is displayed to the user.
After the user submits, the prompt handler tries to parse the input into the expected type. If the operation succeeds, the value is returned to the prompt caller. If it fails, the message defined in error_message
is displayed to the user.
The default formatter simply calls to_string()
on the parsed value, which means that T
must implement the ToString
trait, which normally happens implicitly when you implement the Display
trait.
If your type T
does not satisfy these constraints, you can always manually instantiate the entire struct yourself like this:
use inquire::{CustomType, ui::RenderConfig};
let amount_prompt: CustomType<f64> = CustomType {
message: "How much is your travel going to cost?",
formatter: &|i| format!("${:.2}", i),
default: None,
placeholder: Some("123.45"),
error_message: "Please type a valid number.".into(),
help_message: "Do not use currency and the number should use dots as the decimal separator.".into(),
parser: &|i| match i.parse::<f64>() {
Ok(val) => Ok(val),
Err(_) => Err(()),
},
render_config: RenderConfig::default_static_ref(),
};
Example
use inquire::CustomType;
let amount = CustomType::<f64>::new("How much do you want to donate?")
.with_formatter(&|i| format!("${:.2}", i))
.with_error_message("Please type a valid number")
.with_help_message("Type the amount in US dollars using a decimal point as a separator")
.prompt();
match amount {
Ok(_) => println!("Thanks a lot for donating that much money!"),
Err(_) => println!("We could not process your donation"),
}
Fields
message: &'a str
Message to be presented to the user.
default: Option<(T, CustomTypeFormatter<'a, T>)>
Default value, returned when the user input is empty.
placeholder: Option<&'a str>
Short hint that describes the expected value of the input.
help_message: Option<&'a str>
Help message to be presented to the user.
formatter: CustomTypeFormatter<'a, T>
Function that formats the user input and presents it to the user as the final rendering of the prompt.
parser: CustomTypeParser<'a, T>
Function that parses the user input and returns the result value.
error_message: String
Error message displayed when value could not be parsed from input.
render_config: &'a RenderConfig
RenderConfig to apply to the rendered interface.
Implementations
Creates a CustomType with the provided message and default configuration values.
Sets the default input.
Sets the placeholder.
Sets the help message of the prompt.
Sets the formatter
Sets the parser.
Sets a custom error message displayed when a submission could not be parsed to a value.
Sets the provided color theme to this prompt.
Parses the provided behavioral and rendering options and prompts the CLI user for input according to the defined rules.
Trait Implementations
Auto Trait Implementations
impl<'a, T> !RefUnwindSafe for CustomType<'a, T>
impl<'a, T> !Send for CustomType<'a, T>
impl<'a, T> !Sync for CustomType<'a, T>
impl<'a, T> Unpin for CustomType<'a, T> where
T: Unpin,
impl<'a, T> !UnwindSafe for CustomType<'a, T>
Blanket Implementations
Mutably borrows from an owned value. Read more