public TwitterViewModel(List <TweetGroup> lists, string selectedList)
{
var self = this;
this.SavedLists = Knockout.ObservableArray(lists);
this.EditingList = new TweetGroup(
name: Knockout.Observable(selectedList),
userNames: Knockout.ObservableArray <string>()
);
this.UserNameToAdd = Knockout.Observable("");
this.CurrentTweets = Knockout.ObservableArray(new object[0]);
this.FindSavedList = name => KnockoutUtils.ArrayFirst(self.SavedLists.Value, grp => grp.Name.Value == name, self);
this.AddUser = () => {
if (self.UserNameToAdd.Value != null && self.UserNameToAddIsValid.Value)
{
self.EditingList.UserNames.Push(self.UserNameToAdd.Value);
self.UserNameToAdd.Value = "";
}
};
this.RemoveUser = userName => self.EditingList.UserNames.Remove(userName);
this.SaveChanges = new Action(OnSaveChanges);
this.DeleteList = () => {
var nameToDelete = self.EditingList.Name.Value;
var savedListsExceptOneToDelete = self.SavedLists.Value.Filter(grp => grp.Name.Value != nameToDelete);
self.EditingList.Name.Value =
savedListsExceptOneToDelete.Length == 0
? null
: savedListsExceptOneToDelete[0].Name.Value;
self.SavedLists.Value = savedListsExceptOneToDelete;
};
Knockout.Computed(() => {
// Observe viewModel.editingList.name(), so when it changes
// (i.e., user selects a different list) we know to copy the
// saved list into the editing list
var savedList = self.FindSavedList(self.EditingList.Name.Value);
if (savedList != null)
{
var userNamesCopy = savedList.UserNames.Slice(0);
self.EditingList.UserNames.Value = userNamesCopy;
}
else
{
self.EditingList.UserNames.Value = new string[0];
}
});
this.HasUnsavedChanges = Knockout.Computed(() => {
if (self.EditingList.Name.Value == null)
{
return(self.EditingList.UserNames.Value.Length > 0);
}
var savedData = self.FindSavedList(self.EditingList.Name.Value).UserNames;
var editingData = self.EditingList.UserNames.Value;
return(savedData.Value.Join("|") != editingData.Join("|"));
});
this.UserNameToAddIsValid = Knockout.Computed(() => {
var pattern = @"^\s*[a-zA-Z0-9_]{1,15}\s*$";
return(self.UserNameToAdd.Value == "" ||
self.UserNameToAdd.Value.Match(new Regex(pattern, "g")) != null);
});
this.CanAddUserName = Knockout.Computed(() => {
return(self.UserNameToAddIsValid.Value && self.UserNameToAdd.Value != "");
});
// The active user tweets are (asynchronously) computed from editingList.userNames
Knockout.Computed(() => {
TwitterApi.GetTweetsForUsers <object[]>(
self.EditingList.UserNames.Value,
result => {
self.CurrentTweets.Value = result;
});
});
}
