Draws a diagram in the language of Mermaid with Pele, and names its elements
A diagram with a .mmd file, or with the source option and
lang: :mermaid, calls draw!/3. Pele is a library in
JavaScript, so the function runs Node with the script priv/pele/render.mjs,
through Expresso.Element.Diagram.Tool. The project holds a copy of
pele.js and its license in priv/pele/, so a render needs Node and no
package of npm. version/0 gives the version of the copy.
The script writes the SVG of Pele and the model of its parse(). Pele gives
each part of a diagram the attribute data-id, and the model gives the
ends of each edge and the members of each group. name/1 gives each part
an id and the marks of Expresso.Element.Diagram.Outline, with the plan
of its type, such as Expresso.Element.Diagram.Pele.Flowchart.
Expresso.Element.Diagram.Pele.Plan gives the contract of a plan.
The name of an edge has its two ends and its arrow, as for Graphviz and D2,
so a part names an edge as the source names its ends. Some parts have more
than one element with the same data-id, such as an edge and its label, or
an actor of a sequence diagram at the top and at the bottom. Each element
gets the same id, so a part shows them at the same steps. Only the first
element whose plan gives marks gets them, so the list for a screen reader
holds each part one time.
A diagram of a type without a plan keeps the data-id of Pele as the name
of each part, with no marks.
Summary
Functions
Draw the source of a Mermaid diagram, and return the SVG and the names
Run the script on a source, and return the text of its JSON
Pele has one layout, so a diagram of Mermaid takes no layout option
Give each part of the result of the script its name and its marks
The types of Pele that have a plan, with the names and the marks of their parts
The path of the script that runs Pele
Give a diagram of Pele the colors of the theme
The tool, for Expresso.Element.Diagram.Tool
The version of the copy of Pele
Functions
@spec draw!(String.t(), String.t(), Expresso.Element.Diagram.Font.t()) :: {String.t(), [String.t()]}
Draw the source of a Mermaid diagram, and return the SVG and the names
label names the diagram in a message, such as the path of its file. Pele
writes the family of font in the SVG, and it measures each text with the
advance widths of the characters of font, from
Expresso.Element.Diagram.Font.advances/2. The widths cover each character
of the source and each printable character of ASCII, because Pele can write
a text that is not in the source, such as a number on an axis. The function
raises an
ArgumentError when Node is not present and when Pele cannot draw the
source, with the message of Pele.
@spec json!(String.t(), String.t(), Expresso.Element.Diagram.Font.t()) :: String.t()
Run the script on a source, and return the text of its JSON
The JSON holds the SVG, the type of the diagram and the model of parse().
draw!/3 reads it, and the fixtures of the tests hold it as it is.
@spec layouts() :: [atom()]
Pele has one layout, so a diagram of Mermaid takes no layout option
Give each part of the result of the script its name and its marks
The result holds the SVG, the type of the diagram and the model of
parse(). The function returns the SVG and the names, in the order of the
file.
iex> svg = ~s(<svg><g class="pele-node" data-id="web"></g></svg>)
iex> Expresso.Element.Diagram.Pele.name(%{"svg" => svg, "type" => "flowchart", "model" => %{"edges" => [], "subgraphs" => []}})
{~s(<svg><g class="pele-node" data-id="web" id="web" data-graph-kind="node"></g></svg>), ["web"]}@spec planned() :: [String.t()]
The types of Pele that have a plan, with the names and the marks of their parts
@spec script() :: Path.t()
The path of the script that runs Pele
Give a diagram of Pele the colors of the theme
Pele writes each color as a custom property with a fallback, such as
var(--pele-fg, #1f1f1f), and the style sheet of the deck sets the
properties for the class diagram-pele. Therefore the SVG needs no change.
@spec tool() :: Expresso.Element.Diagram.Tool.t()
The tool, for Expresso.Element.Diagram.Tool
@spec version() :: String.t()
The version of the copy of Pele