This is a simple template tool that works with variable names and
HashMap of String. The Template can be parsed from str
and then you can render it using the variables in HashMap and any
shell commands running through Exec.
str that's easy to write,? to separate the alternatives, uses whichever it can find first. If ? is at the end, leaves it blank instead of erroring out."string" enclosed in " as an alternative if you want to put something instead of blank at the end.chrono,
You can use any format starting with % inside the variable placeholder {} to use a date time format supported by chrono.$( and ) to run it and use the result in the template. You can use other format elements inside it.Simple variables:
rust
let templ = parse_template("hello {name}").unwrap();
let mut vars: HashMap<String, String> = HashMap::new();
vars.insert("name".into(), "world".into());
let rendered = templ
.render(&RenderOptions {
variables: vars,
..Default::default()
})
.unwrap();
assert_eq!(rendered, "hello world");
Safe replace, blank if not present, or literal string if not present:
rust
let templ = parse_template("hello {name?} {lastname?\"User\"}").unwrap();
let vars: HashMap<String, String> = HashMap::new();
let rendered = templ
.render(&RenderOptions {
variables: vars,
..Default::default()
})
.unwrap();
assert_eq!(rendered, "hello User");
Alternate, whichever variable it finds first will be replaced:
rust
let templ = parse_template("hello {nickname?name}").unwrap();
let mut vars: HashMap<String, String> = HashMap::new();
vars.insert("name".into(), "world".into());
let rendered = templ
.render(&RenderOptions {
variables: vars,
..Default::default()
})
.unwrap();
assert_eq!(rendered, "hello world");
Custom Commands:
rust
let templ = parse_template("L=$(printf \"%.2f\" {length})").unwrap();
let mut vars: HashMap<String, String> = HashMap::new();
vars.insert("length".into(), "12.342323".into());
let rendered = templ
.render(&RenderOptions {
wd: PathBuf::from("."),
variables: vars,
shell_commands: true,
})
.unwrap();
assert_eq!(rendered, "L=12.34");
You can turn off Custom Commands for safety:
rust
let templ = parse_template("L=$(printf \"%.2f\" {length})").unwrap();
let mut vars: HashMap<String, String> = HashMap::new();
vars.insert("length".into(), "12.342323".into());
let rendered = templ
.render(&RenderOptions {
wd: PathBuf::from("."),
variables: vars,
shell_commands: false,
})
.unwrap();
assert_eq!(rendered, "L=$(printf \"%.2f\" 12.342323)");
Date Time:
rust
let templ = parse_template("hello {name} at {%Y-%m-%d}").unwrap();
let timefmt = Local::now().format("%Y-%m-%d");
let output = format!("hello world at {}", timefmt);
let mut vars: HashMap<String, String> = HashMap::new();
vars.insert("name".into(), "world".into());
let rendered = templ
.render(&RenderOptions {
wd: PathBuf::from("."),
variables: vars,
shell_commands: false,
})
.unwrap();
assert_eq!(rendered, output);
Makes a RenderIter<'a> that can generate incremented strings from the given Template and the RenderOptions. The Iterator will have -N appended where N is the number representing the number of instance.
rust
let templ = parse_template("hello {name}").unwrap();
let mut vars: HashMap<String, String> = HashMap::new();
vars.insert("name".into(), "world".into());
let options = RenderOptions {
variables: vars,
..Default::default()
};
let mut names = options.render_iter(&templ);
assert_eq!("hello world-1", names.next().unwrap());
assert_eq!("hello world-2", names.next().unwrap());
assert_eq!("hello world-3", names.next().unwrap());
{} will be replaced with empty string. Although you can use "0", "1", etc as variable names in the template and the render options variables.printf bash command to format things the way you want.
Like a template this is $(printf "%.2f" {weight}) kg. should be rendered with the correct float formatting.