Better Resource Management

model.go

@@ -7,7 +7,36 @@ import (
 	todotxt "github.com/br0xen/go-todotxt"
 )
 
+// diskListChanged returns true if the task list in todo.txt
+// is different than what we have previously loaded.
+func (a *AppState) diskListChanged() bool {
+	if !a.taskListLoaded {
+		return false
+	}
+	curr, err := todotxt.LoadFromFilename(a.getTodoFile())
+	if err != nil {
+		return false
+	}
+	return curr.String() != a.TaskList.String()
+}
+
+// diskDoneListChanged returns true if the task list in done.txt
+// is different than what we have previously loaded.
+func (a *AppState) diskDoneListChanged() bool {
+	if !a.doneListLoaded {
+		return false
+	}
+	curr, err := todotxt.LoadFromFilename(a.getDoneFile())
+	if err != nil {
+		return false
+	}
+	return curr.String() != a.DoneList.String()
+}
+
 func (a *AppState) addTask(taskString string) error {
+	if a.diskListChanged() {
+		return a.e(ResStrListChanged)
+	}
 	t, err := todotxt.ParseTask(taskString)
 	if err != nil {
 		return err
@@ -20,6 +49,9 @@ func (a *AppState) addTask(taskString string) error {
 }
 
 func (a *AppState) toggleTaskComplete(id int) error {
+	if a.diskListChanged() {
+		return a.e(ResStrListChanged)
+	}
 	var task *todotxt.Task
 	var err error
 	if task, err = a.TaskList.GetTask(id); err != nil {
@@ -34,12 +66,15 @@ func (a *AppState) toggleTaskComplete(id int) error {
 }
 
 func (a *AppState) archiveTask(id int) error {
+	if a.diskListChanged() {
+		return a.e(ResStrListChanged)
+	}
 	var err error
 	var task *todotxt.Task
 	if task, err = a.TaskList.GetTask(id); err != nil {
 		return err
 	}
-	if err := a.TaskList.ArchiveTaskToFile(*task, app.getDoneFile()); err != nil {
+	if err := a.TaskList.ArchiveTaskToFile(*task, a.getDoneFile()); err != nil {
 		return err
 	}
 	a.TaskList.RemoveTask(*task)
@@ -47,6 +82,9 @@ func (a *AppState) archiveTask(id int) error {
 }
 
 func (a *AppState) unarchiveTask(id int) error {
+	if a.diskListChanged() {
+		return a.e(ResStrListChanged)
+	}
 	var err error
 	var task *todotxt.Task
 	if task, err = a.DoneList.GetTask(id); err != nil {
@@ -112,6 +150,7 @@ func (a *AppState) LoadTaskList() error {
 	var tl todotxt.TaskList
 	tl, err = todotxt.LoadFromFilename(a.getTodoFile())
 	a.TaskList = &tl
+	a.taskListLoaded = true
 	return err
 }
 
@@ -120,13 +159,20 @@ func (a *AppState) LoadDoneList() error {
 	var tl todotxt.TaskList
 	tl, err = todotxt.LoadFromFilename(a.getDoneFile())
 	a.DoneList = &tl
+	a.doneListLoaded = true
 	return err
 }
 
 func (a *AppState) WriteList() error {
+	if !a.taskListLoaded {
+		return a.e(ResStrTaskListNotLoaded)
+	}
 	return a.TaskList.WriteToFilename(a.getTodoFile())
 }
 
 func (a *AppState) WriteDoneList() error {
+	if !a.doneListLoaded {
+		return a.e(ResStrDoneListNotLoaded)
+	}
 	return a.DoneList.WriteToFilename(a.getDoneFile())
 }