Merge pull request #13 from Skarlso/master

Encapsulate database to its own type for standard error handling.

db/files.go

@@ -7,15 +7,8 @@ import (
 // AddFile is used to add the md5 of a file name which is uploaded to our application
 // this will enable us to randomize the URL without worrying about the file names
 func AddFile(fileName, token string) error {
-	SQL, err := database.Prepare("insert into files values(?,?)")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
-
-	if err != nil {
-		log.Println(err)
-	}
+	SQL := database.prepare("insert into files values(?,?)")
+	tx := database.begin()
 	_, err = tx.Stmt(SQL).Exec(fileName, token)
 	if err != nil {
 		log.Println(err)
@@ -30,7 +23,7 @@ func AddFile(fileName, token string) error {
 func GetFileName(token string) (string, error) {
 	sql := "select name from files where autoName=?"
 	var fileName string
-	rows, err := database.Query(sql, fileName)
+	rows := database.query(sql, fileName)
 	if rows.Next() {
 		err := rows.Scan(&fileName)
 		if err != nil {

db/tasks.go

@@ -2,19 +2,49 @@ package db
 
 import (
 	"database/sql"
-	_ "github.com/mattn/go-sqlite3" //we want to use sqlite natively
-	md "github.com/shurcooL/github_flavored_markdown"
-	"github.com/thewhitetulip/Tasks/types"
 	"log"
 	"strings"
 	"time"
+
+	_ "github.com/mattn/go-sqlite3" //we want to use sqlite natively
+	md "github.com/shurcooL/github_flavored_markdown"
+	"github.com/thewhitetulip/Tasks/types"
 )
 
-var database *sql.DB
+var database Database
 var err error
 
+//Database encapsulates database
+type Database struct {
+	db *sql.DB
+}
+
+func (db Database) begin() (tx *sql.Tx) {
+	tx, err := db.db.Begin()
+	if err != nil {
+		log.Println(err)
+	}
+	return tx
+}
+
+func (db Database) prepare(q string) (stmt *sql.Stmt) {
+	stmt, err := db.db.Prepare(q)
+	if err != nil {
+		log.Println(err)
+	}
+	return stmt
+}
+
+func (db Database) query(q string, args ...interface{}) (rows *sql.Rows) {
+	rows, err := db.db.Query(q, args...)
+	if err != nil {
+		log.Println(err)
+	}
+	return rows
+}
+
 func init() {
-	database, err = sql.Open("sqlite3", "./tasks.db")
+	database.db, err = sql.Open("sqlite3", "./tasks.db")
 	if err != nil {
 		log.Println(err)
 	}
@@ -22,7 +52,7 @@ func init() {
 
 //Close function closes this database connection
 func Close() {
-	database.Close()
+	database.db.Close()
 }
 
 //GetTasks retrieves all the tasks depending on the
@@ -46,10 +76,7 @@ func GetTasks(status string) types.Context {
 		getTasksql = basicSQL + " where finish_date is not null order by priority desc, created_date asc"
 	}
 
-	rows, err := database.Query(getTasksql)
-	if err != nil {
-		log.Println(err)
-	}
+	rows := database.query(getTasksql)
 	defer rows.Close()
 	for rows.Next() {
 		err := rows.Scan(&TaskID, &TaskTitle, &TaskContent, &TaskCreated, &TaskPriority)
@@ -73,10 +100,7 @@ func GetTaskByID(id int) types.Context {
 
 	getTasksql := "select id, title, content, priority from task where id=?"
 
-	rows, err := database.Query(getTasksql, id)
-	if err != nil {
-		log.Println(err)
-	}
+	rows := database.query(getTasksql, id)
 	defer rows.Close()
 	if rows.Next() {
 		err := rows.Scan(&task.Id, &task.Title, &task.Content, &task.Priority)
@@ -92,153 +116,56 @@ func GetTaskByID(id int) types.Context {
 
 //TrashTask is used to delete the task
 func TrashTask(id int) error {
-	trashSQL, err := database.Prepare("update task set is_deleted='Y',last_modified_at=datetime() where id=?")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
-	if err != nil {
-		log.Println(err)
-	}
-	_, err = tx.Stmt(trashSQL).Exec(id)
-	if err != nil {
-		log.Println("doing rollback")
-		tx.Rollback()
-	} else {
-		tx.Commit()
-	}
+	err := taskQuery("update task set is_deleted='Y',last_modified_at=datetime() where id=?", id)
 	return err
 }
 
 //CompleteTask  is used to mark tasks as complete
 func CompleteTask(id int) error {
-	stmt, err := database.Prepare("update task set is_deleted='Y', finish_date=datetime(),last_modified_at=datetime() where id=?")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
-	if err != nil {
-		log.Println(err)
-	}
-	_, err = tx.Stmt(stmt).Exec(id)
-	if err != nil {
-		log.Println(err)
-		tx.Rollback()
-	} else {
-		tx.Commit()
-	}
+	err := taskQuery("update task set is_deleted='Y', finish_date=datetime(),last_modified_at=datetime() where id=?", id)
 	return err
 }
 
 //DeleteAll is used to empty the trash
 func DeleteAll() error {
-	stmt, err := database.Prepare("delete from task where is_deleted='Y'")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
-	if err != nil {
-		log.Println(err)
-	}
-	_, err = tx.Stmt(stmt).Exec()
-	if err != nil {
-		log.Println("doing rollback")
-		tx.Rollback()
-	} else {
-		tx.Commit()
-	}
+	err := taskQuery("delete from task where is_deleted='Y'")
 	return err
 }
 
 //RestoreTask is used to restore tasks from the Trash
 func RestoreTask(id int) error {
-	restoreSQL, err := database.Prepare("update task set is_deleted='N',last_modified_at=datetime() where id=?")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
-	if err != nil {
-		log.Println(err)
-	}
-	_, err = tx.Stmt(restoreSQL).Exec(id)
-	if err != nil {
-		log.Println("doing rollback")
-		tx.Rollback()
-	} else {
-		tx.Commit()
-	}
+	err := taskQuery("update task set is_deleted='N',last_modified_at=datetime() where id=?", id)
 	return err
 }
 
-//RestoreTask is used to restore tasks from the Trash
+//RestoreTaskFromComplete is used to restore tasks from the Trash
 func RestoreTaskFromComplete(id int) error {
-	restoreSQL, err := database.Prepare("update task set finish_date=null,last_modified_at=datetime() where id=?")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
-	if err != nil {
-		log.Println(err)
-	}
-	_, err = tx.Stmt(restoreSQL).Exec(id)
-	if err != nil {
-		log.Println("doing rollback")
-		tx.Rollback()
-	} else {
-		tx.Commit()
-	}
+	err := taskQuery("update task set finish_date=null,last_modified_at=datetime() where id=?", id)
 	return err
 }
 
 //DeleteTask is used to delete the task from the database
 func DeleteTask(id int) error {
-	deleteSQL, err := database.Prepare("delete from task where id = ?")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
-	if err != nil {
-		log.Println(err)
-	}
-	_, err = tx.Stmt(deleteSQL).Exec(id)
-	if err != nil {
-		log.Println(err)
-		tx.Rollback()
-	} else {
-		tx.Commit()
-	}
+	err := taskQuery("delete from task where id = ?", id)
 	return err
 }
 
 //AddTask is used to add the task in the database
 func AddTask(title, content string, taskPriority int) error {
-	restoreSQL, err := database.Prepare("insert into task(title, content, priority, created_date, last_modified_at) values(?,?,?,datetime(), datetime())")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
-	_, err = tx.Stmt(restoreSQL).Exec(title, content, taskPriority)
-	if err != nil {
-		log.Println(err)
-		tx.Rollback()
-	} else {
-		tx.Commit()
-	}
+	err := taskQuery("insert into task(title, content, priority, created_date, last_modified_at) values(?,?,?,datetime(), datetime())", title, content, taskPriority)
 	return err
 }
 
 //UpdateTask is used to update the tasks in the database
 func UpdateTask(id int, title string, content string) error {
-	SQL, err := database.Prepare("update task set title=?, content=? where id=?")
-	if err != nil {
-		log.Println(err)
-	}
-	tx, err := database.Begin()
+	err := taskQuery("update task set title=?, content=? where id=?", title, content)
+	return err
+}
 
-	if err != nil {
-		log.Println(err)
-	}
-	_, err = tx.Stmt(SQL).Exec(title, content, id)
+func taskQuery(sql string, args ...interface{}) error {
+	SQL := database.prepare("update task set title=?, content=? where id=?")
+	tx := database.begin()
+	_, err = tx.Stmt(SQL).Exec(args...)
 	if err != nil {
 		log.Println(err)
 		tx.Rollback()
@@ -258,10 +185,8 @@ func SearchTask(query string) types.Context {
 	var TaskCreated time.Time
 	var context types.Context
 
-	rows, err := database.Query(stmt, query, query)
-	if err != nil {
-		log.Println(err)
-	}
+	rows := database.query(stmt, query, query)
+
 	for rows.Next() {
 		err := rows.Scan(&TaskID, &TaskTitle, &TaskContent, &TaskCreated)
 		if err != nil {