Designing cross-platform GUI apps with Fyne
Storing Data
You now have a fully functional app to track your to-do items, but the app will forget the items when you exit. To remedy this, you can connect to a database or store data in a file. However, Fyne lets you store your data in Preferences, a simple key-value store used to easily keep track of user interface state and small data storage without worrying about file storage or connection handling. You can access this feature using the Preferences() method on the App type created earlier.
Loading To-Do Items
You need to ensure that any existing to-do items are loaded when the app starts. To do this, you can simply set up the todos variable to be the result of a load call. Immediately before calling loadUI, you need to call
list = loadTODOs(a.Preferences())
This call will pass your application preferences to a new loadTODOs function that will return a slice of all stored to-dos.
Saving the Data
Before you have data to parse, you need to save it! To do this, you will use another new method, saveTODOs, which will take the current slice to save and a reference to the preferences you will be using:
saveTODOs(todos, p)
Be sure to call this method inside deleteTODO and addTODO after updating the data.
The methods that actually do the work in this example are really simple – you just concatenate all the items to a single string using a joiner constant and then split the items out on load, as shown in Listing 11.
Listing 11
storage.go
01 package main
02
03 import "fyne.io/fyne/v2"
04
05 const joiner = "|"
06
07 func loadTODOs(p fyne.Preferences) []string {
08 all := p.String("items")
09 if all == "" {
10 return []string{}
11 }
12 return strings.Split(all, joiner)
13 }
14
15 func saveTODOs(items []string, p fyne.Preferences) {
16 allItems := strings.Join(items, joiner)
17 p.SetString("items", allItems)
18 }
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Red Hat Adds New Deployment Option for Enterprise Linux Platforms
Red Hat has re-imagined enterprise Linux for an AI future with Image Mode.
-
OSJH and LPI Release 2024 Open Source Pros Job Survey Results
See what open source professionals look for in a new role.
-
Proton 9.0-1 Released to Improve Gaming with Steam
The latest release of Proton 9 adds several improvements and fixes an issue that has been problematic for Linux users.
-
So Long Neofetch and Thanks for the Info
Today is a day that every Linux user who enjoys bragging about their system(s) will mourn, as Neofetch has come to an end.
-
Ubuntu 24.04 Comes with a “Flaw"
If you're thinking you might want to upgrade from your current Ubuntu release to the latest, there's something you might want to consider before doing so.
-
Canonical Releases Ubuntu 24.04
After a brief pause because of the XZ vulnerability, Ubuntu 24.04 is now available for install.
-
Linux Servers Targeted by Akira Ransomware
A group of bad actors who have already extorted $42 million have their sights set on the Linux platform.
-
TUXEDO Computers Unveils Linux Laptop Featuring AMD Ryzen CPU
This latest release is the first laptop to include the new CPU from Ryzen and Linux preinstalled.
-
XZ Gets the All-Clear
The back door xz vulnerability has been officially reverted for Fedora 40 and versions 38 and 39 were never affected.
-
Canonical Collaborates with Qualcomm on New Venture
This new joint effort is geared toward bringing Ubuntu and Ubuntu Core to Qualcomm-powered devices.