flowchart

Working with Edges

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	n1 := f.AddNode("n1")
	n2 := f.AddNode("n2")
	// define some Edges
	e1 := f.AddEdge(n1, n2)
	e2 := f.AddEdge(n1, n2)
	// you can access and modify the Node members afterwards
	e2.From = n2
	e2.To = n1
	// define the Edge shape (EdgeStyles may override the shape)
	e1.Shape = flowchart.EShapeDottedLine
	// add text (you can also directly access e1.Text slice)
	e1.AddLines("first line", "second line")
	e1.AddLines("third line")
	// CSS styling (see EdgeStyle for more details)
	e2.Style = f.EdgeStyle("es1")
	// Previously defined Edges can be looked up
	f.GetEdge(1).Style.Stroke = flowchart.ColorCyan
	fmt.Print(f)
}

Output:

graph TB
n1["n1"]
n2["n2"]
n1 -.-|"first line<br/>second line<br/>third line"| n2
n2 --> n1
linkStyle 1 stroke:#0ff

Accessing the readonly fields of an Edge

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	n1 := f.AddNode("n1")
	n2 := f.AddNode("n2")
	e1 := f.AddEdge(n1, n2)
	e2 := f.AddEdge(n1, n2)
	// the ID of an Edge is actually the order of the Edge creation
	fmt.Println(e2.ID(), e1.ID())
}

Output:

1 0

Working with EdgeStyles

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	n1 := f.AddNode("n1")
	n2 := f.AddNode("n2")
	e1 := f.AddEdge(n1, n2)
	e2 := f.AddEdge(n1, n2)
	// create one or more styles
	es1 := f.EdgeStyle("es1")
	es2 := f.EdgeStyle("es2")
	// and assign them to Edges
	e1.Style = es1
	// you can also lookup previously defined EdgeStyles
	e2.Style = f.EdgeStyle("es2")
	// there are some CSS shortcuts
	es2.Stroke = flowchart.ColorRed
	es2.StrokeWidth = 2
	es2.StrokeDash = 5
	// but you can also add additional styles, just in case
	es2.More = "font-size:20px"
	fmt.Print(f)
}

Output:

graph TB
n1["n1"]
n2["n2"]
n1 --> n2
linkStyle 0 stroke-width:1px
n1 --> n2
linkStyle 1 stroke:#f00,stroke-width:2px,stroke-dasharray:5px,font-size:20px

Defining default linkStyles and curve interpolation

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	f.DefaultEdgeStyle = f.EdgeStyle("my_style_1")
	f.DefaultEdgeStyle.Interpolation = flowchart.InterpolationBasis
	fmt.Print(f)
}

Output:

graph TB
linkStyle default interpolate basis

Accessing the readonly fields of an EdgeStyle

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	es := f.EdgeStyle("this_is_my_id")
	// get a copy of the id field
	fmt.Println(es.ID())
}

Output:

this_is_my_id

Working with Flowcharts

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	// define some Subgraphs
	// see Subgraph for details about what you can do with them
	sg1 := f.AddSubgraph("sg1")
	sg1.Title = "Generating Flowchart graphs"
	// define some Nodes
	// see Node and NodeStyle for details about what you can do with them
	n1 := sg1.AddNode("n1")
	n2 := sg1.AddNode("n2")
	// define some Edges
	// see Edge and EdgeStyle for details about what you can do with them
	f.AddEdge(n1, n2)
	// you can lookup already defined entities
	// but if the ID is not found nil is returned
	sgX := f.GetSubgraph("sg2")
	nX := f.GetNode("n3")
	eX := f.GetEdge(2)
	fmt.Println(sgX, nX, eX)
	// same way you get nil if you try to add an existing ID
	sgY := f.AddSubgraph("sg1")
	nY := f.AddNode("n1")
	// actually this works, since Edges don't have a real ID
	eY := f.AddEdge(n1, n2)
	fmt.Println(sgY, nY, eY)
	// you can iterate over all entities defined in the Flowcharts
	// and all of its Subgraphs
	for _, item := range f.ListSubgraphs() {
		fmt.Printf("%s\n", item.ID())
	}
	for _, item := range f.ListNodes() {
		fmt.Printf("%s\n", item.ID())
	}
	for _, item := range f.ListEdges() {
		fmt.Printf("%d\n", item.ID())
	}
}

Output:

<nil> <nil> <nil>
<nil> <nil> n1 --> n2

sg1
n1
n2
0
1

Generating URLs for the mermaid live editor

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	f.AddEdge(f.AddNode("n1"), f.AddNode("n2"))
	// you can also use f.ViewInBrowser() to open the URL in browser directly
	fmt.Println(f.LiveURL())
}

Output:

https://mermaid.live/view/#pako:eNqqVkrOT0lVslJKL0osyFAIcYrJyzOMjlHKM4xRio3JyzMCsY0gbEMFXd2YUgMD41SFPKOYPCUdpdzUotzEzBQlq2qlkozUXJA5KalpiaU5JUq1tYAAAAD__yEwHQk=

Working with Nodes

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	// define some Nodes
	n1 := f.AddNode("n1")
	n2 := f.AddNode("n2")
	// define the Node shape
	n1.Shape = flowchart.NShapeRoundRect
	// add text (you can also directly access n1.Text slice)
	n1.AddLines("first line", "second line")
	n1.AddLines("third line")
	// you may add a link
	n2.Link = "http://www.example.com"
	n2.LinkText = "tooltip"
	// CSS styling (see NodeStyle for more details)
	n2.Style = f.NodeStyle("ns1")
	// Previously defined Nodes can be looked up
	f.GetNode("n2").Style.Fill = flowchart.ColorCyan
	fmt.Print(f)
}

Output:

graph TB
classDef ns1 fill:#0ff
n1("first line<br/>second line<br/>third line")
n2["n2"]
class n2 ns1
click n2 "http://www.example.com" "tooltip"

Accessing the readonly fields of a Node

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	n1 := f.AddNode("this_is_my_id")
	// get a copy of the id field
	fmt.Println(n1.ID())
}

Output:

this_is_my_id

Working with NodeStyles

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	n1 := f.AddNode("n1")
	n2 := f.AddNode("n2")
	// create one or more styles
	ns1 := f.NodeStyle("ns1")
	ns2 := f.NodeStyle("ns2")
	// and assign them to Nodes
	n1.Style = ns1
	// you can also lookup previously defined NodeStyles
	n2.Style = f.NodeStyle("ns2")
	// there are some CSS shortcuts
	ns2.Fill = flowchart.ColorYellow
	ns2.Stroke = flowchart.ColorBlue
	ns2.StrokeWidth = 2
	ns2.StrokeDash = 5
	// but you can also add additional styles, just in case
	ns2.More = "font-size:20px"
	fmt.Print(f)
}

Output:

graph TB
classDef ns1 stroke-width:1px
classDef ns2 fill:#ff0,stroke:#00f,stroke-width:2px,stroke-dasharray:5px,font-size:20px
n1["n1"]
class n1 ns1
n2["n2"]
class n2 ns2

Accessing the readonly fields of a NodeStyle

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	ns := f.NodeStyle("this_is_my_id")
	// get a copy of the id field
	fmt.Println(ns.ID())
}

Output:

this_is_my_id

Working with Subgraphs

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	// add some Subgraphs
	sg1 := f.AddSubgraph("sg1")
	sg1.Title = "vpc-123"
	sg2 := sg1.AddSubgraph("sg2")
	sg2.Title = "AZ a"
	// oops we forgot to get the reference ...
	sg1.AddSubgraph("sg3")
	// ... but we can also look it up
	sg3 := f.GetSubgraph("sg3")
	sg3.Title = "AZ b"
	// add some Nodes to different Subgraphs
	f.AddEdge(sg2.AddNode("i-123"), sg2.AddNode("mydb"))
	f.AddEdge(sg3.AddNode("i-456"), f.GetNode("mydb"))
	fmt.Print(f)
}

Output:

graph TB
subgraph vpc-123
subgraph AZ a
i-123["i-123"]
mydb["mydb"]
end
subgraph AZ b
i-456["i-456"]
end
end
i-123 --> mydb
i-456 --> mydb

Adding the same ID multiple times won't work

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	f.AddNode("myid1")
	// myid1 can be used since we deal with a different type
	sg := f.AddSubgraph("myid1")
	// myid1 can't be used since for both types it was already defined
	n := sg.AddNode("myid1")
	s := sg.AddSubgraph("myid1")
	fmt.Println(n, s)
}

Output:

<nil> <nil>

Accessing the readonly fields of a Subgraph

package main

import (
	"fmt"

	"github.com/Heiko-san/mermaidgen/flowchart"
)

func main() {
	f := flowchart.NewFlowchart()
	sg := f.AddSubgraph("this_is_my_id")
	sg.Title = "this is my title"
	// get a copy of the id field
	id := sg.ID()
	// get a pointer to the top level Flowchart
	fx := sg.Flowchart()
	fmt.Println(id, f == fx)
}

Output:

this_is_my_id true