sequence

ExampleDiagram_Activate turns a participant's activation bar on, which shows it doing something rather than waiting.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncRequest("Alice", "Bob", "How are you?").
		Activate("Bob").
		SyncResponse("Bob", "Alice", "Fine, thanks").
		Deactivate("Bob").
		Build()

}

Output:
sequenceDiagram
    Alice->>Bob: How are you?
    activate Bob
    Bob-->>Alice: Fine, thanks
    deactivate Bob

ExampleDiagram_Actor declares someone taking part, drawn as a stick figure rather than a box.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		Actor("Alice").
		Participant("Bob").
		SyncRequest("Alice", "Bob", "How are you?").
		Build()

}

Output:
sequenceDiagram
    actor Alice
    participant Bob
    Alice->>Bob: How are you?

ExampleDiagram_AltElse begins an alternative path.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AltStart("is logged in").
		AltElse("is not").
		AltEnd().
		Build()

}

Output:
sequenceDiagram
    alt is logged in
    else is not
    end

ExampleDiagram_AltEnd closes the choice AltStart opened.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AltStart("is logged in").
		AltEnd().
		Build()

}

Output:
sequenceDiagram
    alt is logged in
    end

ExampleDiagram_AltStart opens a choice between paths. AltElse begins each alternative and AltEnd closes the whole thing.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AltStart("is logged in").
		SyncResponse("Bob", "Alice", "Here you are").
		AltElse("is not").
		SyncResponse("Bob", "Alice", "Please log in").
		AltEnd().
		Build()

}

Output:
sequenceDiagram
    alt is logged in
    Bob-->>Alice: Here you are
    else is not
    Bob-->>Alice: Please log in
    end

ExampleDiagram_AsyncRequest draws a call that does not wait for a reply.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AsyncRequest("Alice", "Bob", "Start the job").
		Build()

}

Output:
sequenceDiagram
    Alice->)Bob: Start the job

ExampleDiagram_AsyncRequestWithActivation draws an asynchronous call that turns the bar on.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AsyncRequestWithActivation("Alice", "Bob", "Start the job").
		Build()

}

Output:
sequenceDiagram
    Alice->>+Bob: Start the job

ExampleDiagram_AsyncRequestf draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AsyncRequestf("Alice", "Bob", "Start job %d", 7).
		Build()

}

Output:
sequenceDiagram
    Alice->)Bob: Start job 7

ExampleDiagram_AsyncRequestfWithActivation draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AsyncRequestfWithActivation("Alice", "Bob", "Start job %d", 7).
		Build()

}

Output:
sequenceDiagram
    Alice->>+Bob: Start job 7

ExampleDiagram_AsyncResponse draws a reply to a call that was not waiting.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AsyncResponse("Bob", "Alice", "Job finished").
		Build()

}

Output:
sequenceDiagram
    Bob--)Alice: Job finished

ExampleDiagram_AsyncResponseWithActivation draws an asynchronous reply that turns the bar off.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AsyncResponseWithActivation("Bob", "Alice", "Job finished").
		Build()

}

Output:
sequenceDiagram
    Bob-->>-Alice: Job finished

ExampleDiagram_AsyncResponsef draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AsyncResponsef("Bob", "Alice", "Job %d finished", 7).
		Build()

}

Output:
sequenceDiagram
    Bob--)Alice: Job 7 finished

ExampleDiagram_AsyncResponsefWithActivation draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AsyncResponsefWithActivation("Bob", "Alice", "Job %d finished", 7).
		Build()

}

Output:
sequenceDiagram
    Bob-->>-Alice: Job 7 finished

ExampleDiagram_AutoNumber numbers the messages, so a discussion can refer to one of them by number.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AutoNumber().
		SyncRequest("Alice", "Bob", "How are you?").
		SyncResponse("Bob", "Alice", "Fine, thanks").
		Build()

}

Output:
sequenceDiagram
    autonumber
    Alice->>Bob: How are you?
    Bob-->>Alice: Fine, thanks

ExampleDiagram_AutoNumber_second shows that numbering is a call rather than an option, so it can be turned on partway through a chain.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		AutoNumber().
		SyncRequest("Alice", "Bob", "How are you?").
		Build()

}

Output:
sequenceDiagram
    autonumber
    Alice->>Bob: How are you?

ExampleDiagram_BoxEnd closes the box BoxStart opened.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		BoxStart([]string{"Alice"}).
		Participant("Alice").
		BoxEnd().
		Build()

}

Output:
sequenceDiagram
    box Alice
    participant Alice
    end

ExampleDiagram_BoxStart draws a box around several participants, which is how a diagram says which of them belong to one system.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		BoxStart([]string{"Alice", "Bob"}).
		Participant("Alice").
		Participant("Bob").
		BoxEnd().
		Build()

}

Output:
sequenceDiagram
    box Alice & Bob
    participant Alice
    participant Bob
    end

ExampleDiagram_BreakEnd closes the block BreakStart opened.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		BreakStart("the request is invalid").
		BreakEnd().
		Build()

}

Output:
sequenceDiagram
    break the request is invalid
    end

ExampleDiagram_BreakStart opens a block that stops the flow when it happens.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		BreakStart("the request is invalid").
		SyncResponse("Bob", "Alice", "400 Bad Request").
		BreakEnd().
		Build()

}

Output:
sequenceDiagram
    break the request is invalid
    Bob-->>Alice: 400 Bad Request
    end

ExampleDiagram_Build writes the diagram and reports the error the chain recorded.

package main

import (
	"fmt"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	err := sequence.NewDiagram(nil).
		SyncRequest("Alice", "Bob", "How are you?").
		Build()
	fmt.Println("error:", err)

}

Output:
error: output writer must not be nil

ExampleDiagram_CreateActor brings an actor into being partway through.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		Participant("System").
		CreateActor("Reviewer").
		SyncRequest("System", "Reviewer", "Please review").
		Build()

}

Output:
sequenceDiagram
    participant System
    create actor Reviewer
    System->>Reviewer: Please review

ExampleDiagram_CreateParticipant brings a participant into being partway through, which is how a diagram shows something being started rather than having been there all along.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		Participant("Alice").
		CreateParticipant("Worker").
		SyncRequest("Alice", "Worker", "Start").
		Build()

}

Output:
sequenceDiagram
    participant Alice
    create participant Worker
    Alice->>Worker: Start

ExampleDiagram_CriticalEnd closes the block CriticalStart opened.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		CriticalStart("connect to the database").
		CriticalEnd().
		Build()

}

Output:
sequenceDiagram
    critical connect to the database
    end

ExampleDiagram_CriticalOption begins what happens instead when the critical block cannot go ahead.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		CriticalStart("connect to the database").
		CriticalOption("the network is down").
		CriticalEnd().
		Build()

}

Output:
sequenceDiagram
    critical connect to the database
    option the network is down
    end

ExampleDiagram_CriticalStart opens a block that has to happen, with CriticalOption for each thing that can go wrong instead.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		CriticalStart("connect to the database").
		SyncRequest("Service", "Database", "Connect").
		CriticalOption("the network is down").
		SyncRequest("Service", "Operator", "Page").
		CriticalEnd().
		Build()

}

Output:
sequenceDiagram
    critical connect to the database
    Service->>Database: Connect
    option the network is down
    Service->>Operator: Page
    end

ExampleDiagram_Deactivate turns the bar off again.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		Activate("Bob").
		Deactivate("Bob").
		Build()

}

Output:
sequenceDiagram
    activate Bob
    deactivate Bob

ExampleDiagram_DestroyActor ends an actor.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		Actor("Reviewer").
		DestroyActor("Reviewer").
		Build()

}

Output:
sequenceDiagram
    actor Reviewer
    destroy Reviewer

ExampleDiagram_DestroyParticipant ends a participant, drawn with a cross.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		Participant("Alice").
		Participant("Worker").
		SyncRequest("Alice", "Worker", "Stop").
		DestroyParticipant("Worker").
		Build()

}

Output:
sequenceDiagram
    participant Alice
    participant Worker
    Alice->>Worker: Stop
    destroy Worker

ExampleDiagram_Error reports the same error Build does, for code that wants to look before writing anything.

package main

import (
	"fmt"
	"io"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	d := sequence.NewDiagram(io.Discard).SyncRequest("Alice", "Bob", "How are you?")
	fmt.Println("error:", d.Error())

}

Output:
error: <nil>

ExampleDiagram_LF adds a blank line to the diagram body.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncRequest("Alice", "Bob", "How are you?").
		LF().
		SyncResponse("Bob", "Alice", "Fine, thanks").
		Build()

}

Output:
sequenceDiagram
    Alice->>Bob: How are you?

    Bob-->>Alice: Fine, thanks

ExampleDiagram_LoopEnd closes the block LoopStart opened.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		LoopStart("every minute").
		SyncRequest("Alice", "Bob", "Still there?").
		LoopEnd().
		Build()

}

Output:
sequenceDiagram
    loop every minute
    Alice->>Bob: Still there?
    end

ExampleDiagram_LoopStart opens a block that repeats, and LoopEnd closes it.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		LoopStart("every minute").
		SyncRequest("Alice", "Bob", "Still there?").
		LoopEnd().
		Build()

}

Output:
sequenceDiagram
    loop every minute
    Alice->>Bob: Still there?
    end

ExampleDiagram_NoteLeftOf puts a note to the left of a participant.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		NoteLeftOf("Alice", "Alice is waiting").
		Build()

}

Output:
sequenceDiagram
    note left of Alice: Alice is waiting

ExampleDiagram_NoteOver puts a note across one or more participants. Two named with a comma between them is a note spanning both.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		NoteOver("Alice", "Thinking it over").
		NoteOver("Alice,Bob", "Both are waiting").
		Build()

}

Output:
sequenceDiagram
    note over Alice: Thinking it over
    note over Alice,Bob: Both are waiting

ExampleDiagram_NoteRightOf puts a note to the right of a participant.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		NoteRightOf("Bob", "Bob is busy").
		Build()

}

Output:
sequenceDiagram
    note right of Bob: Bob is busy

ExampleDiagram_OptEnd closes the block OptStart opened.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		OptStart("if the cache is cold").
		OptEnd().
		Build()

}

Output:
sequenceDiagram
    opt if the cache is cold
    end

ExampleDiagram_OptStart opens a block that may or may not happen, which is a choice with only one path.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		OptStart("if the cache is cold").
		SyncRequest("Bob", "Database", "Fetch").
		OptEnd().
		Build()

}

Output:
sequenceDiagram
    opt if the cache is cold
    Bob->>Database: Fetch
    end

ExampleDiagram_ParallelAnd begins another path running at the same time.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		ParallelStart("lint").
		ParallelAnd("test").
		ParallelEnd().
		Build()

}

Output:
sequenceDiagram
    par lint
    and test
    end

ExampleDiagram_ParallelEnd closes the paths ParallelStart opened.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		ParallelStart("lint").
		ParallelEnd().
		Build()

}

Output:
sequenceDiagram
    par lint
    end

ExampleDiagram_ParallelStart opens paths that run at the same time. ParallelAnd begins each one after the first and ParallelEnd closes them.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		ParallelStart("lint").
		SyncRequest("CI", "Linter", "Run").
		ParallelAnd("test").
		SyncRequest("CI", "Tester", "Run").
		ParallelEnd().
		Build()

}

Output:
sequenceDiagram
    par lint
    CI->>Linter: Run
    and test
    CI->>Tester: Run
    end

ExampleDiagram_Participant declares someone taking part, drawn as a box. Declaring one is what fixes the order they appear in; a participant a message names is drawn anyway, at the point it is first mentioned.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		Participant("Bob").
		Participant("Alice").
		SyncRequest("Alice", "Bob", "How are you?").
		Build()

}

Output:
sequenceDiagram
    participant Bob
    participant Alice
    Alice->>Bob: How are you?

ExampleDiagram_RequestError draws a call that failed, drawn with a cross at the end.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		RequestError("Alice", "Bob", "Timed out").
		Build()

}

Output:
sequenceDiagram
    Alice-xBob: Timed out

ExampleDiagram_RequestErrorf draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		RequestErrorf("Alice", "Bob", "Timed out after %ds", 30).
		Build()

}

Output:
sequenceDiagram
    Alice-xBob: Timed out after 30s

ExampleDiagram_ResponseError draws a reply that failed.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		ResponseError("Bob", "Alice", "Refused").
		Build()

}

Output:
sequenceDiagram
    Bob--xAlice: Refused

ExampleDiagram_ResponseErrorf draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		ResponseErrorf("Bob", "Alice", "Refused with %d", 503).
		Build()

}

Output:
sequenceDiagram
    Bob--xAlice: Refused with 503

ExampleDiagram_String returns the diagram without needing a writer, which is how it is handed to a markdown code block.

package main

import (
	"io"
	"os"

	md "github.com/nao1215/markdown"
	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	diagram := sequence.NewDiagram(io.Discard).
		SyncRequest("Alice", "Bob", "How are you?").
		String()

	_ = md.NewMarkdown(os.Stdout).
		CodeBlocks(md.SyntaxHighlightMermaid, diagram).
		Build()

}

Output:
```mermaid
sequenceDiagram
    Alice->>Bob: How are you?
```

ExampleDiagram_SyncRequest draws a solid arrow with a filled head, the ordinary call.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncRequest("Alice", "Bob", "How are you?").
		Build()

}

Output:
sequenceDiagram
    Alice->>Bob: How are you?

ExampleDiagram_SyncRequestWithActivation draws a call that also turns the receiver's activation bar on.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncRequestWithActivation("Alice", "Bob", "How are you?").
		Build()

}

Output:
sequenceDiagram
    Alice->>+Bob: How are you?

ExampleDiagram_SyncRequestf draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncRequestf("Alice", "Bob", "Retry %d of %d", 2, 3).
		Build()

}

Output:
sequenceDiagram
    Alice->>Bob: Retry 2 of 3

ExampleDiagram_SyncRequestfWithActivation draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncRequestfWithActivation("Alice", "Bob", "Retry %d", 2).
		Build()

}

Output:
sequenceDiagram
    Alice->>+Bob: Retry 2

ExampleDiagram_SyncResponse draws a dashed arrow with a filled head, the ordinary reply.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncResponse("Bob", "Alice", "Fine, thanks").
		Build()

}

Output:
sequenceDiagram
    Bob-->>Alice: Fine, thanks

ExampleDiagram_SyncResponseWithActivation draws a reply that also turns the bar off.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncResponseWithActivation("Bob", "Alice", "Fine, thanks").
		Build()

}

Output:
sequenceDiagram
    Bob-->>-Alice: Fine, thanks

ExampleDiagram_SyncResponsef draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncResponsef("Bob", "Alice", "%d items", 7).
		Build()

}

Output:
sequenceDiagram
    Bob-->>Alice: 7 items

ExampleDiagram_SyncResponsefWithActivation draws the same from a format string.

package main

import (
	"os"

	"github.com/nao1215/markdown/mermaid/sequence"
)

func main() {
	_ = sequence.NewDiagram(os.Stdout).
		SyncResponsefWithActivation("Bob", "Alice", "%d items", 7).
		Build()

}

Output:
sequenceDiagram
    Bob-->>-Alice: 7 items