API Reference: engrapha_diagrams¶

All public classes and their constructors. Every diagram inherits from DiagramBase which exposes save(filename), as_flowable(), and theme.

Base¶

DiagramBase(width, height, theme=None, caption=None)
ResponsiveDrawingFlowable(drawing, caption=None)

Member	Purpose
`save(filename)`	Export to PDF, SVG, PNG, or JPG
`as_flowable()`	Return `[drawing]` (or `[drawing, caption_paragraph]`)
`build()`	Render into `self.drawing`
`theme`	Active `DiagramTheme`

Diagram classes¶

Class	Purpose
`Flowchart`	Process / decision / I/O flowchart
`SequenceDiagram`	UML sequence with lifelines
`ClassDiagram`	UML class with attributes / methods
`ERDiagram`	Chen-notation entity-relationship
`SchemaDiagram`	SQL table diagram with foreign keys
`NetworkDiagram`	Network topology, topologies
`ArchitectureDiagram`	Multi-tier system diagram
`C4ContainerDiagram`	C4 Model container diagram
`AWSDiagram`	AWS vector icon diagram
`LayeredStack`	OSI / memory-hierarchy layers
`StateMachine`	DFA / lifecycle states
`TimingDiagram`	Digital signal waveforms
`GitDiagram`	Branch commit timeline

Flowchart¶

Flowchart(width, height, theme=None, caption=None,
          direction="TB", scale_factor=None)

Method	Purpose
`terminal(id, label, x, y)`	Pill start/end
`process(id, label, x, y)`	Rectangle
`decision(id, label, x, y)`	Diamond
`io_box(id, label, x, y)`	Parallelogram
`connector(id, label, x, y)`	Circle
`predefined(id, label, x, y)`	Double-walled rectangle
`custom(id, label, x, y, custom_draw)`	Your own shape (callback)
`edge(from, to, label="", branch="", path=None, orthogonal=False)`	Directed edge

SequenceDiagram¶

SequenceDiagram(width, height, theme=None, caption=None,
                row_height=32, margin=120)

Method	Purpose
`actor(id, label)`	Participant lifeline
`message(from, to, label, arrow="solid")`	Arrow between two lifelines
`activate(actor_id)`	Start activation bar
`deactivate(actor_id)`	End activation bar
`divider(text="")`	Horizontal time divider

Arrow styles: "solid", "dashed", "solid_open", "dashed_open".

ClassDiagram¶

ClassDiagram(width, height=None, theme=None, caption=None, class_w=100)

Method	Purpose
`uml_class(id, name, x, y, stereotype, attributes, methods, width)`	Add class box
`relate(from, to, kind, label, from_mult, to_mult)`	Add relationship

kind is one of "inheritance", "realization", "composition", "aggregation", "association", "dependency".

ERDiagram¶

ERDiagram(width, height, theme=None, caption=None,
          entity_w=90, entity_h=28, rel_w=60, rel_h=28,
          attr_rx=36, attr_ry=14)

Method	Purpose
`entity(name, x, y, weak)`	Strong (or weak) entity
`relationship(name, x, y, identifying)`	Relationship diamond
`attribute(name, parent, x, y, pk, derived, multivalued)`	Attribute oval
`entity_attributes(entity_id, attrs, distance, start_angle)`	Batch placement around a circle
`connect(from, to, card_from, card_to, total_from, total_to)`	Line + cardinality badges

SchemaDiagram¶

SchemaDiagram(width, height, theme=None, caption=None)

Method	Purpose
`table(name, columns, x, y)`	Add table
`relation(from_table, from_col, to_table, to_col)`	Foreign key link

columns is a list of (name, type, {"pk": bool, "fk": bool}).

NetworkDiagram¶

NetworkDiagram(width, height, theme=None, caption=None)

Method	Purpose
`node(id, label, x, y, kind, custom_draw, label_pos, custom_clip)`	Add node
`link(from, to, label, bidirectional)`	Edge between two nodes
`bus_topology(node_ids, labels, kind, bus_y)`	Bus topology helper
`star_topology(center_id, center_label, spoke_ids, spoke_labels, ...)`	Star helper
`ring_topology(node_ids, labels, kind)`	Ring helper
`mesh_topology(node_ids, labels, kind)`	Full mesh helper
`tree_topology(parent_child_map, node_labels, node_kinds)`	Tree helper

ArchitectureDiagram¶

ArchitectureDiagram(width, height, theme=None, caption=None,
                    orientation="horizontal")

Method	Purpose
`client(name, label, x, y)`	Top-tier client
`service(name, label, x, y)`	Middle-tier service
`database(name, label, x, y)`	Bottom-tier database
`queue(name, label, x, y)`	Bottom-tier queue
`connect(from, to, label)`	Orthogonal routed edge

C4ContainerDiagram¶

C4ContainerDiagram(width, height, theme=None, caption=None)

Method	Purpose
`system(name, desc)`	Software system context
`container(name, tech, desc)`	Container with tech
`relate(from, to, label)`	Relationship arc

AWSDiagram¶

AWSDiagram(width, height, theme=None, caption=None, orientation="horizontal")

Inherits ArchitectureDiagram. Adds:

Method	Visual
`ec2(name, label, x, y)`	Server blade chassis
`rds(name, label, x, y)`	Multi-disc cylinder
`s3(name, label, x, y)`	Trapezoidal bucket
`sqs(name, label, x, y)`	Stadium with slots
`lambda_fn(name, label, x, y)`	Lambda (λ) symbol

Use connect(...) inherited from ArchitectureDiagram.

LayeredStack¶

LayeredStack(width, height, theme=None, caption=None,
             margin=12, layer_h=30, corner_radius=5)

Method	Purpose
`layer(label, sublabel, fill, stroke, height)`	Append one layer
`divider()`	Draw thicker separator after last layer

StateMachine¶

StateMachine(width, height, theme=None, caption=None,
             state_r=22, direction=None, state_label_max_width=82,
             transition_label_max_width=96)

Method	Purpose
`state(id, label, x, y, initial, accepting, custom_draw)`	Add circle state
`transition(from, to, label, pill, offset)`	Directed edge

initial=True draws a filled-circle + arrow entry marker; accepting=True draws a double ring.

TimingDiagram¶

TimingDiagram(width, height, theme=None, caption=None, grid=True)

Method	Purpose
`signal(name, transitions)`	Custom (time, level) transitions
`clock(name, period, duty, cycles)`	Regular 50 % duty-cycle clock

transitions is a list of (time_pt, level) where level ∈ {0, 1}.

GitDiagram¶

GitDiagram(width, height, theme=None, caption=None, commit_spacing=65)

Method	Purpose
`commit(branch, label)`	Record a commit
`branch(parent_branch, child_branch)`	Branch off a parent
`merge(from_branch, to_branch, label)`	Merge branch -> branch

Theme matching¶

ed.DiagramTheme.from_notes_theme(notes_theme)  # returns DiagramTheme

Theme presets: ed.DARK, ed.LIGHT, plus ten augmented presets available only via the notes pathway (OCEAN_DARK, FOREST_DARK, etc.).