1. About

An example preprocessor for mdbook.

2. Configurations

2.1 Configurations

Add the configuration below to book.toml.

[preprocessor.ynn]
command = "<path to executable>"
patterns = [
    ["<old>", "<new>"],
    ...
]
timestamp = "<format>"

patterns (optional)

patterns provides a simple replace functionality with user-defined regular expressions.
- "<old>" is a regular expression.
- "<new>" is generally a string literal, but $0, $1, ... can be used to represent capture groups.
timestamp (optional)

When timestamp is specified, the last commit date of the source file is prepended to each page.

The prepended timestamp is enclosed in <div id='mdbook_preprocessor_last_modified'></div>, making it customizable via CSS.

Commit dates are retrieved this command:
```
git log -1 --pretty='format:<format>' <file>
```

2.2 Example

[preprocessor.ynn]
command = "/Users/user/.cargo/bin/mdbook_preprocessor"
patterns = [
    [":warning:", "⚠️"],
    [":check:", "✅"],
    ["==(.*?)==", "<font color=Red>$1</font>"],
]
timestamp = "🕒 last modified: %cs"

The last pattern converts ==[string]== into <font color=Red>[string]</font>.

3. Installation

3.1 From Local

$ cargo install --locked --path .

3.2 From GitHub

$ cargo install --locked --git 'https://github.com/your-diary/mdbook_preprocessor'

4. Build

$ cargo build --release

5. Test

$ cargo test

6. How To Customize This Project

Basically, the only part you may want to edit is the body of the replace() function in src/replacer.rs.

pub fn replace(filepath: &Option<PathBuf>, s: &str, config: &Table) -> String {
    /* ... */
}

Optionally, you may want to fix or add its tests.

For a more advanced but yet simple example, the official example preprocessor would help.

your-diary/mdbook_preprocessor