A Swift package for working with GraphViz.
- Swift 5.1+
- GraphViz (only for rendering)
import GraphViz
var graph = Graph(directed: true)
let a = Node("a"), b = Node("b"), c = Node("c")
graph.append(Edge(from: a, to: b))
graph.append(Edge(from: a, to: c))
var b_c = Edge(from: b, to: c)
b_c.constraint = false
graph.append(b_c)
// Produce DOT language representation
let dot = DOTEncoder().encode(graph)
// Render image using dot layout algorithm
let data = try! graph.render(using: .dot, to: .svg)
let svg = String(data: data, encoding: .utf8)!
digraph {
a -> b
a -> c
b -> c [constraint=false]
}Note: The
render(using:to:)method requires that the GraphViz binary corresponding to the specified layout algorithm is accessible from the current$PATH.
To use the following interface,
add "GraphVizBuilder" to your package's dependencies
and replace import GraphViz with import GraphVizBuilder as needed.
import GraphVizBuilder
let graph = Graph(directed: true) {
"a" --> "b"
"a" --> "c"
("b" --> "c").constraint(false)
}Note: Swift 5.1 may require explicit typecast expressions in order to reconcile use of custom edge operators like
-->. (error: ambiguous reference to member '-->')
Add the GraphViz package to your target dependencies in Package.swift:
import PackageDescription
let package = Package(
name: "YourProject",
dependencies: [
.package(
url: "https://github.com/SwiftDocOrg/GraphViz",
from: "0.1.3"
),
]
)Add GraphViz as a dependency to your target(s):
targets: [
.target(
name: "YourTarget",
dependencies: ["GraphViz"]),To render graphs to SVG, PNG, and other formats,
you must have GraphViz executables (e.g. dot) installed on your system
and accessible from $PATH.
You can install GraphViz from the command line:
# macOS
$ brew install graphviz
# Linux (Ubuntu)
$ sudo apt-get install graphviz
MIT
Mattt (@mattt)