# markdown-it-kroki

> This library was designed to embed [Kroki.io](https://kroki.io/) diagram into [Marp](https://marp.app/) slide decks!!


This library is a plugin for markdown-it to embed figure created by textual syntax.
To use this package, you can embed **Software Diagram** (like UML) written by **code** in Marp slide decks.

See marp sample code.

## Sample

    ---
    marp: true
    ---


    ## plantuml

    ```plantuml[platuml image]
    @startuml
    left to right direction
    actor Guest as g
    package Professional {
    actor Chef as c
    actor "Food Critic" as fc
    }
    package Restaurant {
    usecase "Eat Food" as UC1
    usecase "Pay for Food" as UC2
    usecase "Drink" as UC3
    usecase "Review" as UC4
    }
    fc --> UC4
    g --> UC1
    g --> UC2
    g --> UC3
    @enduml
    ```

![plantuml-sample](img/plantuml-sample.png)

If you want to write diagrams, you can use various syntaxes (such as [PlantUML](https://plantuml.com/) or [Mermaid](https://mermaid-js.github.io/mermaid/#/)) within fenced code blocks.

## How to install

You can install `npm install` command like below.

```bash
npm install -D @kazumatu981/markdown-it-kroki
```

## How to use

Here is the how to use `markdow-it-kroki`.
This section introduces how to create Marp slides deck project,
and introduces how to create Marp slides deck server.

You can find detail [here](https://marp.app/),
and you can learn about marp plugin ecosystem [here](https://marpit.marp.app/usage?id=extend-marpit-by-plugins).

### **[1st step]** Create slides deck project

First, to create a slides deck, you have to create a **Marp Project** directory and initialize a npm project.

```bash
mkdir myslides
cd myslides
npm init -y
```

Then, build a Marp environment.
Install [@marp-team/marp-cli](https://github.com/marp-team/marp-cli).

```bash
npm install -D @marp-team/marp-cli
```

> Off-course you can install as **global package** (like `npm install -g @marp-team/marp-cli`), or **run at-once** (like `npx`).

### **[2nd step]** Download this project and install

```bash
git clone https://github.com/kazumatu981/markdown-it-kroki.git

cd myslides
npm install -D path/to/markdown-it-kroki
```

### **[3rd step]** Create `marp.config.js`.

Here is the configuration file for **Marp**.

```javascript
module.exports = {
    inputDir: './slides',
    engine: ({ marp }) => marp.use(require('@kazumatu981/markdown-it-kroki'), {
        entrypoint: "https://kroki.io",
    })
}
```

### **[4th step]** Create your slides

On `slies` directory. you create slides-deck. like this.

    ---
    marp: true
    ---


    ## mermaid

    ```mermaid[mermaid image]
    flowchart TD
        Start --> Stop
    ```

### **[5th step]** run server

Run marp server.

```bash
marp -s -c marp.config.js
```

## Detail

### Syntax of Markdown

#### Diagram Language

You have to write diagram language by [fenced code block](https://spec.commonmark.org/0.30/#fenced-code-blocks) syntax, start with **triple back quot** and after that the language.

    ```plantuml

> [!NOTE]  
> This package depends on [Kroki.io](https://kroki.io).   
> If you want to know which **diagram languages are supported**,
> please check the official website at [https://kroki.io/](https://kroki.io/).

#### Alt Text

You can write Alt-text attribute to IMG tag in HTML.
Write in `square blacket` after **Diagram Language**.

    ```mermaid [check your network config..]

### Options of `constructor`

| property-name    | type     | mean                                                   | defaul value              |
| ---------------- | -------- | ------------------------------------------------------ | ------------------------- |
| `entrypoint`     | `string` | The entry point for Kroki server.                      | `'https://kroki.io'`      |
| `containerClass` | `string` | class name of container (`DIV`-tag `class` attribute). | `'kroki-image-container'` |
| `imageFormat`    | `string` | image format of diagram. see [here](https://kroki.io/) | `'svg'`                   |
| `useImg` | `boolean` | use `<img>` tag for embed diagram. ( *for compatibility for past version* ) | `false` |
| `render` | `function` | if you render `html` yourself use this option. see [How To Write `render()` call back](memo/howToWriteRender.md) | `undefined` |

## FAQ

You can find answer of frequently asked questions [here](faq.md).