Serialize Json / Web Services to Observable Collection Model - web-services

Question

I want to ask, so i've consume a web service api and than serialize it into a observable collection of Model.
My question is how i can use this observable collection everywhere, so i don't have to call/get/consume from web services everytime?
So just call the api one time and then can use the data everytime without callng API again?
Thanks

Answer 1

As #thang mentioned above there are many ways to store the data in the app to eliminate calling web service each time.
I will suggest you the way I am doing it:
1.When I retrieve the JSON data from the Web Api I am parsing it to Observable Collection:
ObservableCollection<User> usersList = JsonConvert.DeserializeObject<ObservableCollection<User>>(responseJson).Users;
2.Once I have my list I can also save serialized objects (in JSON format) to the text file (remember that JSON is nothing else like string):
private async void saveUsersToFile(string serializedUsersListAsJson)
{
StorageFolder storageFolder = ApplicationData.Current.LocalFolder;
StorageFile usersFile = await storageFolder.CreateFileAsync("users.txt", CreationCollisionOption.OpenIfExists);
await FileIO.WriteTextAsync(usersFile, serializedUsersListAsJson);
}
This step allows you to store the data even if the app is closed and relaunched.
3.When you launch the app you can invoke below method to read data from the file:
private async void retrieveNotes()
{
StorageFolder storageFolder = ApplicationData.Current.LocalFolder;
StorageFile usersFile = await storageFolder.CreateFileAsync("users.txt", CreationCollisionOption.OpenIfExists)
string serializedUsersList = await FileIO.ReadTextAsync(usersFile );
// Deserialize JSON list to the ObservableCollection:
if(serializedUsersList!=null)
{
var usersList= JsonConvert.DeserializeObject<ObservableCollection<User>>(serializedUsersList);
}
4.Last step is to declare Observable Collection field in Pages where you need to use it. For instance if you need to pass this list between Pages you can just use:
Frame.Navigate(typeof(MainPage), usersList);
Remember to read the data from the file once the app is launched. After that you can just use it while app is running. My suggestion is to cache data each time you connect Web Api to retrieve new data.
Hope this will help. If you want to read more about data storage please read below post on my blog:
https://mobileprogrammerblog.wordpress.com/2016/05/23/universal-windows-10-apps-data-storage/

Answer 2

To save the data for next time user open the app
Store the data in local Sqlite database, or serialized the collection to a local file to use later.
To use the data in same section
Store the data in a common object, and retrieve it every time you need to initialize the ViewModel
To use the data across Win 10 device
Store the file / database in OneDrive and sync when needed
If the data size is small and you dont have critical need to have 100% sync data, store it inside roaming folder