Add kanban position task property and migrate existing

pkg/migration/20210725153703.go

@@ -0,0 +1,70 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-2021 Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public Licensee as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public Licensee for more details.
+//
+// You should have received a copy of the GNU Affero General Public Licensee
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package migration
+
+import (
+	"math"
+	"src.techknowlogick.com/xormigrate"
+	"xorm.io/xorm"
+)
+
+type tasks20210725153703 struct {
+	ID             int64   `xorm:"bigint autoincr not null unique pk" json:"id" param:"listtask"`
+	Position       float64 `xorm:"double null" json:"position"`
+	KanbanPosition float64 `xorm:"double null" json:"kanban_position"`
+}
+
+func (tasks20210725153703) TableName() string {
+	return "tasks"
+}
+
+func init() {
+	migrations = append(migrations, &xormigrate.Migration{
+		ID:          "20210725153703",
+		Description: "",
+		Migrate: func(tx *xorm.Engine) error {
+			err := tx.Sync2(tasks20210725153703{})
+			if err != nil {
+				return err
+			}
+
+			tasks := []*tasks20210725153703{}
+			err = tx.Where("position is not null").Find(&tasks)
+			if err != nil {
+				return err
+			}
+
+			// Migrate all old kanban positions to the kanban positions property
+			for _, task := range tasks {
+				task.KanbanPosition = task.Position
+				task.Position = float64(task.ID) * math.Pow(2, 16)
+				_, err = tx.
+					Where("id = ?", task.ID).
+					Cols("kanban_position", "position").
+					Update(task)
+				if err != nil {
+					return err
+				}
+			}
+
+			return nil
+		},
+		Rollback: func(tx *xorm.Engine) error {
+			return nil
+		},
+	})
+}

pkg/models/tasks.go

@@ -118,6 +118,8 @@ type Task struct {
 	// A 64-Bit float leaves plenty of room to initially give tasks a position with 2^16 difference to the previous task
 	// which also leaves a lot of room for rearranging and sorting later.
 	Position float64 `xorm:"double null" json:"position"`
+	// The position of tasks in the kanban board. See the docs for the `position` property on how to use this.
+	KanbanPosition float64 `xorm:"double null" json:"kanban_position"`
 
 	// The user who initially created the task.
 	CreatedBy   *user.User `xorm:"-" json:"created_by" valid:"-"`
@@ -836,6 +838,14 @@ func setTaskBucket(s *xorm.Session, task *Task, originalTask *Task, doCheckBucke
 	return nil
 }
 
+func calculateDefaultTaskPosition(t *Task, position float64) float64 {
+	if position == 0 {
+		return float64(t.ID+1) * math.Pow(2, 16)
+	}
+
+	return position
+}
+
 // Create is the implementation to create a list task
 // @Summary Create a task
 // @Description Inserts a task into a list.
@@ -895,9 +905,8 @@ func createTask(s *xorm.Session, t *Task, a web.Auth, updateAssignees bool) (err
 
 	t.Index = latestTask.Index + 1
 	// If no position was supplied, set a default one
-	if t.Position == 0 {
-		t.Position = float64(latestTask.ID+1) * math.Pow(2, 16)
-	}
+	t.Position = calculateDefaultTaskPosition(latestTask, t.Position)
+	t.KanbanPosition = calculateDefaultTaskPosition(latestTask, t.KanbanPosition)
 	if _, err = s.Insert(t); err != nil {
 		return err
 	}