WWW::MermaidInk Raku package

The function mermaid-ink of the Raku package "WWW::MermaidInk" gets images corresponding to Mermaid-js specifications via the web Mermaid-ink interface of Mermaid-js.

For a "full set" of examples see the file MermaidInk_woven.html.

Usage

use WWW::MermaidInk
loads the package.

mermaid-ink($spec)
retrieves an image defined by the spec $spec from Mermaid's Ink Web interface.

mermaid-ink($spec format => 'md-image')
returns a string that is a Markdown image specification in Base64 format.

mermaid-ink($spec file => fileName)
exports the retrieved image into a specified PNG file.

mermaid-ink($spec file => Whatever)
exports the retrieved image into the file $*CMD ~ /out.png.

Details & Options

Mermaid lets you create diagrams and visualizations using text and code.
Mermaid has different types of diagrams: Flowchart, Sequence Diagram, Class Diagram, State Diagram, Entity Relationship Diagram, User Journey, Gantt, Pie Chart, Requirement Diagram, and others. It is a JavaScript based diagramming and charting tool that renders Markdown-inspired text definitions to create and modify diagrams dynamically.
mermaid-ink uses the Mermaid's functionalities via the Web interface "https://mermaid.ink/img".
The first argument can be a string (that is, a mermaid-js specification) or a list of pairs.
The option "directives" can be used to control the layout of Mermaid diagrams if the first argument is a list of pairs.
mermaid-ink produces images only.

Examples

Basic Examples

Generate a flowchart from a Mermaid specification:

use WWW::MermaidInk;

'graph TD 
   WL --> |ZMQ|Python --> |ZMQ|WL' 
 ==> mermaid-ink(format=>'md-image')

Create a Markdown image expression from a class diagram:

my $spec = q:to/END/;
classDiagram
    Animal <|-- Duck
    Animal <|-- Fish
    Animal <|-- Zebra
    Animal : +int age
    Animal : +String gender
    Animal: +isMammal()
    Animal: +mate()
    class Duck{
        +String beakColor
        +swim()
        +quack()
    }
    class Fish{
        -int sizeInFeet
        -canEat()
    }
    class Zebra{
        +bool is_wild
        +run()
    }
END

mermaid-ink($spec, format=>'md-image')

Scope

The first argument can be a list of pairs -- the corresponding Mermaid-js graph is produced. Here are the edges of directed graph:

my @edges = ['1' => '3', '3' => '1', '1' => '4', '2' => '3', '2' => '4', '3' => '4'];

[1 => 3 3 => 1 1 => 4 2 => 3 2 => 4 3 => 4]

Here is the corresponding mermaid-js image:

mermaid-ink(@edges, format=>'md-image')

Command Line Interface (CLI)

The package provides the CLI script mermaid-ink. Here is its help message:

mermaid-ink --help

# Usage:
#   mermaid-ink <spec> [-o|--file=<Str>] [--format=<Str>] -- Diagram image for Mermaid-JS spec (via mermaid.ink).
#   mermaid-ink [<words> ...] [-o|--file=<Str>] [--format=<Str>] -- Command given as a sequence of words.
#   
#     <spec>             Mermaid-JS spec.
#     -o|--file=<Str>    File to export the image to. [default: '']
#     --format=<Str>     Format of the result; one of "asis", "base64", "md-image", or "none". [default: 'md-image']

Flowchart

This flowchart summarizes the execution path of obtaining Mermaid images in a Markdown document:

graph TD
    UI[/User input/]
    MS{{Mermaid-ink server}}
    Raku{{Raku}}
    MDnb>Markdown document]
    MDIC[[Input cell]]
    MDOC[[Output cell]]
    MI[mermaid-ink]
    TCP[[Text::CodeProcessing]]
    UI --> MDIC -.- MDnb
    MDIC --> MI -.- TCP
    MI --> |spec|MS
    MS --> |image|MI
    MI --> MDOC -.- MDnb
    MDnb -.- TCP -.- Raku

References

Articles

[AA1] Anton Antonov, "Interactive Mermaid diagrams generation via Markdown evaluation", (2022), RakuForPrediction at WordPress.

Functions and packages

[AAf1] Anton Antonov, MermaidInk Mathematica resource function, (2022-2023), Wolfram Function Repository.