日本語 | Русский | 中文 | 한국어 | Español | Français
The Package markdown is a simple markdown builder in golang. The markdown package assembles Markdown using method chaining, not uses a template engine like html/template. The syntax of Markdown follows GitHub Markdown.
The markdown package was initially developed to save test results in nao1215/spectest. Therefore, the markdown package implements the features required by spectest. For example, the markdown package supports mermaid diagrams (entity relationship diagram, sequence diagram, flowchart, pie chart, quadrant chart, state diagram, Gantt chart, architecture diagram), which was a necessary feature in spectest.
Additionally, complex code that increases the complexity of the library, such as generating nested lists, will not be added. I want to keep this library as simple as possible.
- OS: Linux, macOS, Windows
- Go: 1.23 or later
- Heading; H1, H2, H3, H4, H5, H6
- Blockquote
- Bullet list
- Ordered list
- Checkbox list
- Code blocks
- Horizontal rule
- Table
- Text formatting; bold, italic, code, strikethrough, bold italic
- Text with link
- Text with image
- Plain text
- Details
- Alerts; NOTE, TIP, IMPORTANT, CAUTION, WARNING
- mermaid sequence diagram
- mermaid entity relationship diagram
- mermaid flowchart
- mermaid pie chart
- mermaid quadrant chart
- mermaid state diagram
- mermaid Gantt chart
- mermaid architecture diagram (beta feature)
- Generate badges; RedBadge(), YellowBadge(), GreenBadge().
- Generate an index for a directory full of markdown files; GenerateIndex()
package main import ( "os" md "github.com/nao1215/markdown" ) func main() { md.NewMarkdown(os.Stdout). H1("This is H1"). PlainText("This is plain text"). H2f("This is %s with text format", "H2"). PlainTextf("Text formatting, such as %s and %s, %s styles.", md.Bold("bold"), md.Italic("italic"), md.Code("code")). H2("Code Block"). CodeBlocks(md.SyntaxHighlightGo, `package main import "fmt" func main() { fmt.Println("Hello, World!") }`). H2("List"). BulletList("Bullet Item 1", "Bullet Item 2", "Bullet Item 3"). OrderedList("Ordered Item 1", "Ordered Item 2", "Ordered Item 3"). H2("CheckBox"). CheckBox([]md.CheckBoxSet{ {Checked: false, Text: md.Code("sample code")}, {Checked: true, Text: md.Link("Go", "https://golang.org")}, {Checked: false, Text: md.Strikethrough("strikethrough")}, }). H2("Blockquote"). Blockquote("If you can dream it, you can do it."). H3("Horizontal Rule"). HorizontalRule(). H2("Table"). Table(md.TableSet{ Header: []string{"Name", "Age", "Country"}, Rows: [][]string{ {"David", "23", "USA"}, {"John", "30", "UK"}, {"Bob", "25", "Canada"}, }, }). H2("Image"). PlainTextf(md.Image("sample_image", "./sample.png")). Build() }Output:
# This is H1 This is plain text ## This is H2 with text format Text formatting, such as **bold** and *italic*, `code` styles. ## Code Block ```go package main import "fmt" func main() { fmt.Println("Hello, World!") } ``` ## List - Bullet Item 1 - Bullet Item 2 - Bullet Item 3 1. Ordered Item 1 2. Ordered Item 2 3. Ordered Item 3 ## CheckBox - [ ] `sample code` - [x] [Go](https://golang.org) - [ ] ~~strikethrough~~ ## Blockquote > If you can dream it, you can do it. ### Horizontal Rule --- ## Table | NAME | AGE | COUNTRY | |-------|-----|---------| | David | 23 | USA | | John | 30 | UK | | Bob | 25 | Canada | ## Image  If you want to see how it looks in Markdown, please refer to the following link.
You can generate Markdown using go generate. Please define code to generate Markdown first. Then, run "go generate ./..." to generate Markdown.
package main import ( "os" md "github.com/nao1215/markdown" ) //go:generate go run main.go func main() { f, err := os.Create("generated.md") if err != nil { panic(err) } defer f.Close() md.NewMarkdown(f). H1("go generate example"). PlainText("This markdown is generated by `go generate`"). Build() }Run below command:
go generate ./...# go generate example This markdown is generated by `go generate` The markdown package can create alerts. Alerts are useful for displaying important information in Markdown. This syntax is supported by GitHub. Code example:
md.NewMarkdown(f). H1("Alert example"). Note("This is note").LF(). Tip("This is tip").LF(). Important("This is important").LF(). Warning("This is warning").LF(). Caution("This is caution").LF(). Build()# Alert example > [!NOTE] > This is note > [!TIP] > This is tip > [!IMPORTANT] > This is important > [!WARNING] > This is warning > [!CAUTION] > This is caution Your alert will look like this;
Note
This is note
Tip
This is tip
Important
This is important
Warning
This is warning
Caution
This is caution
The markdown package can create red, yellow, and green status badges. Code example:
md.NewMarkdown(os.Stdout). H1("badge example"). RedBadge("red_badge"). YellowBadge("yellow_badge"). GreenBadge("green_badge"). BlueBadge("blue_badge"). Build()# badge example     Your badge will look like this;
package main import ( "os" "github.com/nao1215/markdown" "github.com/nao1215/mermaid/sequence" ) //go:generate go run main.go func main() { diagram := sequence.NewDiagram(io.Discard). Participant("Sophia"). Participant("David"). Participant("Subaru"). LF(). SyncRequest("Sophia", "David", "Please wake up Subaru"). SyncResponse("David", "Sophia", "OK"). LF(). LoopStart("until Subaru wake up"). SyncRequest("David", "Subaru", "Wake up!"). SyncResponse("Subaru", "David", "zzz"). SyncRequest("David", "Subaru", "Hey!!!"). BreakStart("if Subaru wake up"). SyncResponse("Subaru", "David", "......"). BreakEnd(). LoopEnd(). LF(). SyncResponse("David", "Sophia", "wake up, wake up"). String() markdown.NewMarkdown(os.Stdout). H2("Sequence Diagram"). CodeBlocks(markdown.SyntaxHighlightMermaid, diagram). Build() }Plain text output: markdown is here
## Sequence Diagram ```mermaid sequenceDiagram participant Sophia participant David participant Subaru Sophia->>David: Please wake up Subaru David-->>Sophia: OK loop until Subaru wake up David->>Subaru: Wake up! Subaru-->>David: zzz David->>Subaru: Hey!!! break if Subaru wake up Subaru-->>David: ...... end end David-->>Sophia: wake up, wake up ``` Mermaid output:
sequenceDiagram participant Sophia participant David participant Subaru Sophia->>David: Please wake up Subaru David-->>Sophia: OK loop until Subaru wake up David->>Subaru: Wake up! Subaru-->>David: zzz David->>Subaru: Hey!!! break if Subaru wake up Subaru-->>David: ...... end end David-->>Sophia: wake up, wake up package main import ( "os" "github.com/nao1215/markdown" "github.com/nao1215/markdown/mermaid/er" ) //go:generate go run main.go func main() { f, err := os.Create("generated.md") if err != nil { panic(err) } defer f.Close() teachers := er.NewEntity( "teachers", []*er.Attribute{ { Type: "int", Name: "id", IsPrimaryKey: true, IsForeignKey: false, IsUniqueKey: true, Comment: "Teacher ID", }, { Type: "string", Name: "name", IsPrimaryKey: false, IsForeignKey: false, IsUniqueKey: false, Comment: "Teacher Name", }, }, ) students := er.NewEntity( "students", []*er.Attribute{ { Type: "int", Name: "id", IsPrimaryKey: true, IsForeignKey: false, IsUniqueKey: true, Comment: "Student ID", }, { Type: "string", Name: "name", IsPrimaryKey: false, IsForeignKey: false, IsUniqueKey: false, Comment: "Student Name", }, { Type: "int", Name: "teacher_id", IsPrimaryKey: false, IsForeignKey: true, IsUniqueKey: true, Comment: "Teacher ID", }, }, ) schools := er.NewEntity( "schools", []*er.Attribute{ { Type: "int", Name: "id", IsPrimaryKey: true, IsForeignKey: false, IsUniqueKey: true, Comment: "School ID", }, { Type: "string", Name: "name", IsPrimaryKey: false, IsForeignKey: false, IsUniqueKey: false, Comment: "School Name", }, { Type: "int", Name: "teacher_id", IsPrimaryKey: false, IsForeignKey: true, IsUniqueKey: true, Comment: "Teacher ID", }, }, ) erString := er.NewDiagram(f). Relationship( teachers, students, er.ExactlyOneRelationship, // "||" er.ZeroToMoreRelationship, // "}o" er.Identifying, // "--" "Teacher has many students", ). Relationship( teachers, schools, er.OneToMoreRelationship, // "|}" er.ExactlyOneRelationship, // "||" er.NonIdentifying, // ".." "School has many teachers", ). String() err = markdown.NewMarkdown(f). H2("Entity Relationship Diagram"). CodeBlocks(markdown.SyntaxHighlightMermaid, erString). Build() if err != nil { panic(err) } }Plain text output: markdown is here
## Entity Relationship Diagram ```mermaid erDiagram teachers ||--o{ students : "Teacher has many students" teachers }|..|| schools : "School has many teachers" schools { int id PK,UK "School ID" string name "School Name" int teacher_id FK,UK "Teacher ID" } students { int id PK,UK "Student ID" string name "Student Name" int teacher_id FK,UK "Teacher ID" } teachers { int id PK,UK "Teacher ID" string name "Teacher Name" } ``` Mermaid output:
erDiagram teachers ||--o{ students : "Teacher has many students" teachers }|..|| schools : "School has many teachers" schools { int id PK,UK "School ID" string name "School Name" int teacher_id FK,UK "Teacher ID" } students { int id PK,UK "Student ID" string name "Student Name" int teacher_id FK,UK "Teacher ID" } teachers { int id PK,UK "Teacher ID" string name "Teacher Name" } package main import ( "io" "os" "github.com/nao1215/markdown" "github.com/nao1215/markdown/mermaid/flowchart" ) //go:generate go run main.go func main() { f, err := os.Create("generated.md") if err != nil { panic(err) } defer f.Close() fc := flowchart.NewFlowchart( io.Discard, flowchart.WithTitle("mermaid flowchart builder"), flowchart.WithOrientalTopToBottom(), ). NodeWithText("A", "Node A"). StadiumNode("B", "Node B"). SubroutineNode("C", "Node C"). DatabaseNode("D", "Database"). LinkWithArrowHead("A", "B"). LinkWithArrowHeadAndText("B", "D", "send original data"). LinkWithArrowHead("B", "C"). DottedLinkWithText("C", "D", "send filtered data"). String() err = markdown.NewMarkdown(f). H2("Flowchart"). CodeBlocks(markdown.SyntaxHighlightMermaid, fc). Build() if err != nil { panic(err) } }Plain text output: markdown is here
## Flowchart ```mermaid --- title: mermaid flowchart builder --- flowchart TB A["Node A"] B(["Node B"]) C[["Node C"]] D[("Database")] A-->B B-->|"send original data"|D B-->C C-. "send filtered data" .-> D ``` Mermaid output:
flowchart TB A["Node A"] B(["Node B"]) C[["Node C"]] D[("Database")] A-->B B-->|"send original data"|D B-->C C-. "send filtered data" .-> D package main import ( "io" "os" "github.com/nao1215/markdown" "github.com/nao1215/markdown/mermaid/piechart" ) //go:generate go run main.go func main() { f, err := os.Create("generated.md") if err != nil { panic(err) } defer f.Close() chart := piechart.NewPieChart( io.Discard, piechart.WithTitle("mermaid pie chart builder"), piechart.WithShowData(true), ). LabelAndIntValue("A", 10). LabelAndFloatValue("B", 20.1). LabelAndIntValue("C", 30). String() err = markdown.NewMarkdown(f). H2("Pie Chart"). CodeBlocks(markdown.SyntaxHighlightMermaid, chart). Build() if err != nil { panic(err) } }Plain text output: markdown is here
## Pie Chart ```mermaid %%{init: {"pie": {"textPosition": 0.75}, "themeVariables": {"pieOuterStrokeWidth": "5px"}} }%% pie showData title mermaid pie chart builder "A" : 10 "B" : 20.100000 "C" : 30 ``` Mermaid output:
%%{init: {"pie": {"textPosition": 0.75}, "themeVariables": {"pieOuterStrokeWidth": "5px"}} }%% pie showData title mermaid pie chart builder "A" : 10 "B" : 20.100000 "C" : 30 The mermaid provides a feature to visualize infrastructure architecture as a beta version, and that feature has been introduced.
package main import ( "io" "os" "github.com/nao1215/markdown" "github.com/nao1215/markdown/mermaid/arch" ) //go:generate go run main.go func main() { f, err := os.Create("generated.md") if err != nil { panic(err) } defer f.Close() diagram := arch.NewArchitecture(io.Discard). Service("left_disk", arch.IconDisk, "Disk"). Service("top_disk", arch.IconDisk, "Disk"). Service("bottom_disk", arch.IconDisk, "Disk"). Service("top_gateway", arch.IconInternet, "Gateway"). Service("bottom_gateway", arch.IconInternet, "Gateway"). Junction("junctionCenter"). Junction("junctionRight"). LF(). Edges( arch.Edge{ ServiceID: "left_disk", Position: arch.PositionRight, Arrow: arch.ArrowNone, }, arch.Edge{ ServiceID: "junctionCenter", Position: arch.PositionLeft, Arrow: arch.ArrowNone, }). Edges( arch.Edge{ ServiceID: "top_disk", Position: arch.PositionBottom, Arrow: arch.ArrowNone, }, arch.Edge{ ServiceID: "junctionCenter", Position: arch.PositionTop, Arrow: arch.ArrowNone, }). Edges( arch.Edge{ ServiceID: "bottom_disk", Position: arch.PositionTop, Arrow: arch.ArrowNone, }, arch.Edge{ ServiceID: "junctionCenter", Position: arch.PositionBottom, Arrow: arch.ArrowNone, }). Edges( arch.Edge{ ServiceID: "junctionCenter", Position: arch.PositionRight, Arrow: arch.ArrowNone, }, arch.Edge{ ServiceID: "junctionRight", Position: arch.PositionLeft, Arrow: arch.ArrowNone, }). Edges( arch.Edge{ ServiceID: "top_gateway", Position: arch.PositionBottom, Arrow: arch.ArrowNone, }, arch.Edge{ ServiceID: "junctionRight", Position: arch.PositionTop, Arrow: arch.ArrowNone, }). Edges( arch.Edge{ ServiceID: "bottom_gateway", Position: arch.PositionTop, Arrow: arch.ArrowNone, }, arch.Edge{ ServiceID: "junctionRight", Position: arch.PositionBottom, Arrow: arch.ArrowNone, }).String() //nolint err = markdown.NewMarkdown(f). H2("Architecture Diagram"). CodeBlocks(markdown.SyntaxHighlightMermaid, diagram). Build() if err != nil { panic(err) }Plain text output: markdown is here
## Architecture Diagram ```mermaid architecture-beta service left_disk(disk)[Disk] service top_disk(disk)[Disk] service bottom_disk(disk)[Disk] service top_gateway(internet)[Gateway] service bottom_gateway(internet)[Gateway] junction junctionCenter junction junctionRight left_disk:R -- L:junctionCenter top_disk:B -- T:junctionCenter bottom_disk:T -- B:junctionCenter junctionCenter:R -- L:junctionRight top_gateway:B -- T:junctionRight bottom_gateway:T -- B:junctionRight ``` 
package main import ( "io" "os" "github.com/nao1215/markdown" "github.com/nao1215/markdown/mermaid/state" ) //go:generate go run main.go func main() { f, err := os.Create("generated.md") if err != nil { panic(err) } defer f.Close() diagram := state.NewDiagram(io.Discard, state.WithTitle("Order State Machine")). StartTransition("Pending"). State("Pending", "Order received"). State("Processing", "Preparing order"). State("Shipped", "Order in transit"). State("Delivered", "Order completed"). LF(). TransitionWithNote("Pending", "Processing", "payment confirmed"). TransitionWithNote("Processing", "Shipped", "items packed"). TransitionWithNote("Shipped", "Delivered", "customer received"). LF(). NoteRight("Pending", "Waiting for payment"). NoteRight("Processing", "Preparing items"). LF(). EndTransition("Delivered"). String() err = markdown.NewMarkdown(f). H2("State Diagram"). CodeBlocks(markdown.SyntaxHighlightMermaid, diagram). Build() if err != nil { panic(err) } }Plain text output: markdown is here
## State Diagram ```mermaid --- title: Order State Machine --- stateDiagram-v2 [*] --> Pending Pending : Order received Processing : Preparing order Shipped : Order in transit Delivered : Order completed Pending --> Processing : payment confirmed Processing --> Shipped : items packed Shipped --> Delivered : customer received note right of Pending : Waiting for payment note right of Processing : Preparing items Delivered --> [*] ``` Mermaid output:
--- title: Order State Machine --- stateDiagram-v2 [*] --> Pending Pending : Order received Processing : Preparing order Shipped : Order in transit Delivered : Order completed Pending --> Processing : payment confirmed Processing --> Shipped : items packed Shipped --> Delivered : customer received note right of Pending : Waiting for payment note right of Processing : Preparing items Delivered --> [*] package main import ( "io" "os" "github.com/nao1215/markdown" "github.com/nao1215/markdown/mermaid/quadrant" ) //go:generate go run main.go func main() { f, err := os.Create("generated.md") if err != nil { panic(err) } defer f.Close() chart := quadrant.NewChart(io.Discard, quadrant.WithTitle("Product Prioritization")). XAxis("Low Effort", "High Effort"). YAxis("Low Value", "High Value"). LF(). Quadrant1("Quick Wins"). Quadrant2("Major Projects"). Quadrant3("Fill Ins"). Quadrant4("Thankless Tasks"). LF(). Point("Feature A", 0.9, 0.85). Point("Feature B", 0.25, 0.75). Point("Feature C", 0.15, 0.20). Point("Feature D", 0.80, 0.15). String() err = markdown.NewMarkdown(f). H2("Quadrant Chart"). CodeBlocks(markdown.SyntaxHighlightMermaid, chart). Build() if err != nil { panic(err) } }Plain text output: markdown is here
## Quadrant Chart ```mermaid quadrantChart title Product Prioritization x-axis Low Effort --> High Effort y-axis Low Value --> High Value quadrant-1 Quick Wins quadrant-2 Major Projects quadrant-3 Fill Ins quadrant-4 Thankless Tasks Feature A: [0.90, 0.85] Feature B: [0.25, 0.75] Feature C: [0.15, 0.20] Feature D: [0.80, 0.15] ``` Mermaid output:
quadrantChart title Product Prioritization x-axis Low Effort --> High Effort y-axis Low Value --> High Value quadrant-1 Quick Wins quadrant-2 Major Projects quadrant-3 Fill Ins quadrant-4 Thankless Tasks Feature A: [0.90, 0.85] Feature B: [0.25, 0.75] Feature C: [0.15, 0.20] Feature D: [0.80, 0.15] package main import ( "io" "os" "github.com/nao1215/markdown" "github.com/nao1215/markdown/mermaid/gantt" ) //go:generate go run main.go func main() { f, err := os.Create("generated.md") if err != nil { panic(err) } defer f.Close() chart := gantt.NewChart( io.Discard, gantt.WithTitle("Project Schedule"), gantt.WithDateFormat("YYYY-MM-DD"), ). Section("Planning"). DoneTaskWithID("Requirements", "req", "2024-01-01", "5d"). DoneTaskWithID("Design", "design", "2024-01-08", "3d"). Section("Development"). CriticalActiveTaskWithID("Coding", "code", "2024-01-12", "10d"). TaskAfterWithID("Review", "review", "code", "2d"). Section("Release"). MilestoneWithID("Launch", "launch", "2024-01-26"). String() err = markdown.NewMarkdown(f). H2("Gantt Chart"). CodeBlocks(markdown.SyntaxHighlightMermaid, chart). Build() if err != nil { panic(err) } }Plain text output: markdown is here
## Gantt Chart ```mermaid gantt title Project Schedule dateFormat YYYY-MM-DD section Planning Requirements :done, req, 2024-01-01, 5d Design :done, design, 2024-01-08, 3d section Development Coding :crit, active, code, 2024-01-12, 10d Review :review, after code, 2d section Release Launch :milestone, launch, 2024-01-26, 0d ``` Mermaid output:
gantt title Project Schedule dateFormat YYYY-MM-DD section Planning Requirements :done, req, 2024-01-01, 5d Design :done, design, 2024-01-08, 3d section Development Coding :crit, active, code, 2024-01-12, 10d Review :review, after code, 2d section Release Launch :milestone, launch, 2024-01-26, 0d The markdown package can create an index for Markdown files within the specified directory. This feature was added to generate indexes for Markdown documents produced by nao1215/spectest.
For example, consider the following directory structure:
testdata ├── abc │ ├── dummy.txt │ ├── jkl │ │ └── text.md │ └── test.md ├── def │ ├── test.md │ └── test2.md ├── expected │ └── index.md ├── ghi └── test.mdIn the following implementation, it creates an index markdown file containing links to all markdown files located within the testdata directory.
if err := GenerateIndex( "testdata", // target directory that contains markdown files WithTitle("Test Title"), // title of index markdown WithDescription([]string{"Test Description", "Next Description"}), // description of index markdown ); err != nil { panic(err) }The index Markdown file is created under "target directory/index.md" by default. If you want to change this path, please use the WithWriter() option. The link names in the file will be the first occurrence of H1 or H2 in the target Markdown. If neither H1 nor H2 is present, the link name will be the file name of the destination.
## Test Title Test Description Next Description ### testdata - [test.md](test.md) ### abc - [h2 is here](abc/test.md) ### jkl - [text.md](abc/jkl/text.md) ### def - [h2 is first, not h1](def/test.md) - [h1 is here](def/test2.md) ### expected - [Test Title](expected/index.md)First off, thanks for taking the time to contribute! See CONTRIBUTING.md for more information. Contributions are not only related to development. For example, GitHub Star motivates me to develop! Please feel free to contribute to this project.
Thanks goes to these wonderful people (emoji key):
 CHIKAMATSU Naohiro 💻 |  Karthik Sundari 💻 |  Avihuc 💻 |  Clarance Liberiste Ntwari 💻 |  Amitai Frey 💻 | ||
 Add your contributions | ||||||
This project follows the all-contributors specification. Contributions of any kind welcome!