#template #project #handlebars #guidon


Library to initialize project from templates

16 unstable releases (3 breaking)

new 0.4.1 May 1, 2021
0.4.0 Mar 11, 2021
0.3.0 Jan 12, 2021
0.2.10 Nov 19, 2020
0.2.7 Jul 15, 2020

#32 in Template engine

Download history 25/week @ 2021-01-12 18/week @ 2021-01-19 11/week @ 2021-01-26 3/week @ 2021-02-02 16/week @ 2021-02-09 160/week @ 2021-02-16 3/week @ 2021-02-23 4/week @ 2021-03-02 18/week @ 2021-03-09 4/week @ 2021-03-16 33/week @ 2021-03-23 45/week @ 2021-03-30 29/week @ 2021-04-06 22/week @ 2021-04-13 35/week @ 2021-04-20 27/week @ 2021-04-27

124 downloads per month
Used in guidon-cli


834 lines


guidon performs templating based on handlebars templating system.


Files to be handles needs to have an .hbs extension. Folders and files names can be templatized too : {{folder/subfolder}} The entry point is the Guidon structure.

Basic init

 let mut guidon = Guidon::new(PathBuf::from("path/to/template/dir"));
 let mut vars = BTreeMap::new();
 vars.insert("key1".to_string(), "value1".to_string());

With this initialization:

  • guidon will use the vars map to find substitution values.
  • guidon will parse the directory path/to/template/dir/template
  • the result will be written in path/to/destination

TryNew init

guidon implements a TryNew trait to initialize from a dir or a git repo

TryNew from path

let mut guidon = Guidon::try_new("path/to/template/dir").unwrap();

With this initialization:

  • guidon will init the substitution variables from path/to/template/dir/variables.toml
  • guidon will parse the directory path/to/template/dir/template
let mut guidon = Guidon::try_new("path/to/template/dir/my_vars.toml").unwrap();

With this initialization:

  • guidon will init the substitution variables from path/to/template/dir/my_vars.toml
  • guidon will parse the directory path/to/template/dir

TryNew from CustomTemplate

Guidon can be provided with specific template file and directory to parse.

let custom = CustomTemplate {
    dir_path: Path::new("path/to/template/dir"),
    template_path: Path::new("path/to/my_vars.toml")
let mut guidon = Guidon::try_new(custom);

TryNew from git repo

let git = GitOptions::builder()
let mut guidon = Guidon::try_new(git);

With this initialization

  • guidon will clone the repo to a temporary directory
  • guidon will init the substitutions variables from tmp/dir/template.toml
  • when applying template, guidon will parse the directory tmp/dir/template

The git repo url could be in the form :

  • http[s]://[user[:password]]@uri/repo[.git] where user and password must be part of the url
  • git@uri:repo.git. The key used must be loaded in an ssh-agent instance

Template variables

The configuration file is structured as follows :

# Key value pairs for template substitution
test1 = "test 1"
test2 = "test 2"


  • replace. It's simply replace a string by another in the value. Tell me: {{replace my_var everybody world}} with my_var="Hello everybody ! will render as Tell me: Hello world !.
  • append. Simply append a string to the value. Tell me: {{append my_var "and everybody !"}} with my_var="Hello world" will render as Tell me: Hello world and everybody !.
  • prepend. Prepend a string to the value. Tell me: {{prepend my_var "Sure, "}} with my_var="hello world" will render as Tell me: Sure, hello world.
  • up: Uppercase the value
  • low: Lowercase the value
  • default: default to given value if input is null or empty Tell me: {{default my_var "Oops"}} with my_var not defined will render as Tell me: Oops
  • encrypt: Encrypt the data. The key must be provided
  • decrypt: Decrypt the data

encrypt and decrypt helpers are provide with the crypto feature.


guidon offers the possiblity to provide two callbacks :

  • a variables callback to operate on the variables before applying the template
  • a render callback, which is called if a missing value is detected while rendering the template.

These callbacks could be use for user interaction, or default behaviour.

Variable callback

In this example, the callback will add " cb" to every value.

let cb = |h: &mut BTreeMap<String, String>| {
        h.iter_mut().for_each(|(_, v)|  *v +=" cb");
let mut guidon = Guidon::new(PathBuf::from("template/path"));

Render callback

In this example, the callback will replace any missing value by the key concatenated with "-cb"

// this callback will add `-cb` to the key as a value
let cb = |h: String| {
        let mut s = h.clone();
let mut guidon = Guidon::new(PathBuf::from("template/path"));

File and Directory names

Filnames and directory can also be templatized. Super-{{my_var}}-content.txt will render as Super-boring-content.txt given my_var="boring". If the content of the file is templatized, we have Super-{{my_var}}-content.txt.hbs.//!


guidon uses the log facade.


This project is licensed under either of

at your option.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in guidon by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

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