API Extension: JSON tags and DELETE

code/mytodo/data/db.go

 package data
 
-import "gitlab.reutlingen-university.de/schmolli/todo/model"
+import (
+	"fmt"
+
+	"gitlab.reutlingen-university.de/schmolli/todo/model"
+)
 
 var Todos = []model.Todo{}
 var NextId = 0
+
+func DeleteToDoWithId(id int) (todo *model.Todo, err error) {
+	delIndex := -1
+	for pos, t := range Todos {
+		if t.ID == id {
+			delIndex = pos
+			break
+		}
+	}
+	if delIndex == -1 {
+		return nil, fmt.Errorf("todo with ID %d not found", id)
+	} else {
+		todo := Todos[delIndex]
+		deleteIndex(delIndex)
+		return &todo, nil
+	}
+}
+
+func DeleteAll() {
+	//Create empty slice
+	Todos = make([]model.Todo, 0)
+}
+
+func deleteIndex(pos int) {
+	Todos = append(Todos[:pos], Todos[pos+1:]...)
+}

code/mytodo/handler/todo.go

@@ -13,12 +13,13 @@ import (
 func AddTodo(c *gin.Context) {
 	var todo model.Todo
 	if err := c.BindJSON(&todo); err != nil {
-		c.IndentedJSON(http.StatusBadRequest, fmt.Sprintf("{\"error message\" : \"%s\"}", err.Error()))
+		c.AbortWithError(http.StatusBadRequest, err)
+	} else {
+		todo.ID = data.NextId
+		data.NextId++
+		data.Todos = append(data.Todos, todo)
+		c.IndentedJSON(http.StatusCreated, todo)
 	}
-	todo.ID = data.NextId
-	data.NextId++
-	data.Todos = append(data.Todos, todo)
-	c.IndentedJSON(http.StatusCreated, todo)
 }
 
 func GetTodos(c *gin.Context) {
@@ -28,7 +29,7 @@ func GetTodos(c *gin.Context) {
 func GetToDoByID(c *gin.Context) {
 	id, err := strconv.Atoi(c.Param("id"))
 	if err != nil {
-		c.IndentedJSON(http.StatusBadRequest, gin.H{"message": "illegal id "})
+		c.AbortWithError(http.StatusBadRequest, err)
 		return
 	}
 
@@ -38,5 +39,26 @@ func GetToDoByID(c *gin.Context) {
 			return
 		}
 	}
-	c.IndentedJSON(http.StatusNotFound, gin.H{"message": "Todo not found"})
+	c.AbortWithError(http.StatusNotFound, fmt.Errorf("todo with ID %d not found", id))
+}
+
+func DeleteToDoByID(c *gin.Context) {
+	id, err := strconv.Atoi(c.Param("id"))
+	if err != nil {
+		c.AbortWithError(http.StatusBadRequest, err)
+		return
+	}
+
+	var todo *model.Todo = nil
+	if todo, err = data.DeleteToDoWithId(id); err != nil {
+		c.AbortWithError(http.StatusNotFound, err)
+	}
+
+	c.IndentedJSON(http.StatusOK, *todo)
+}
+
+func DeleteAllTodos(c *gin.Context) {
+	len := len(data.Todos)
+	data.DeleteAll()
+	c.IndentedJSON(http.StatusOK, fmt.Sprintf("Deleted %d todo items", len))
 }

code/mytodo/main.go

@@ -11,5 +11,7 @@ func main() {
 	r.GET("/mytodo/todos", handler.GetTodos)
 	r.GET("/mytodo/todos/:id", handler.GetToDoByID)
 	r.POST("/mytodo/todos", handler.AddTodo)
+	r.DELETE("/mytodo/todos/:id", handler.DeleteToDoByID)
+	r.DELETE("/mytodo/todos/clear", handler.DeleteAllTodos)
 	r.Run(":10000")
 }

code/mytodo/model/todo.go

@@ -2,5 +2,5 @@ package model
 
 type Todo struct {
 	ID          int    `json:"id"`
-	Description string `json:"description"`
+	Description string `json:"description" binding:"required"`
 }