Using databases with web apps is not much different than using them with desktop apps, but there are a few things to keep in mind. The most important thing to note is that a web app allows multiple users. This means you’ll want your database connection to be unique for each user that connects to the web app, rather than global to the app itself (as is common in desktop apps). The simplest way to ensure this is to create the connection to your database in the WebSession.Open event handler, saving a reference to the connection as a property that you add to WebSession.
Month: June 2016
Paul talks with Tom Catchesides of Light Blue Software about how he started using Xojo, the experience of migrating a FileMaker app to Xojo, surnames and retro computers. Don’t miss this fun-filled episode!
I’m sure you’ve all seen the iOS Mail app, which displays the number of unread messages in a small red badge in the top right of the app icon. You can do this too with your Xojo app and the magic of the Declare command.
In a previous post we saw how to implement the Singleton Design Pattern in our Xojo apps. Now, it is time to look at another useful Design Pattern you can use in your apps: the Observer Design Pattern. This one solves the kind of question “How can the ‘x’ controls be automatically notified every time there are changes on ‘y’?” Sound interesting? Let’s see how!
In fact, this is the first of a two part series regarding the Observer Design Pattern. This one will focus on how easy is to implement using the interfaces already available in Xojo for UI controls like the PushButton, the BevelButton, and also for the Timer class. In Part 2, we will see how to implement the Observer Design Pattern from scratch, using our own Classes and Interfaces, so it will be easier to understand the mechanisms behind this Pattern and how to use it.
Xojo is a popular way to create cross-platform apps for Windows, OS X, Linux, Raspberry Pi, web and iOS. I’m not surprised because Xojo makes creating software fast and fun! Xojo really is the best way to create cross-platform software.
One of the best things that Xojo offers to programming newcomers is that they can simply jump-in and start to write code. In a matter of a few hours they’ll have a functional app! Nothing new here. (Or for not-so-newcomers, a fast way of creating a functional prototype from a idea).
But as these users advance in their Xojo skills, they probably will care about coding better and to embrace the OOP way of doing things. After all, Xojo is a modern programming language with Classes, Inheritance, Interfaces and a bunch of the usual OOP paradigms that have much to offer: reusability, better maintainability and a lot of flexibility.
Methods, properties, controls, any member that you add to project items can have its own scope. What is the scope? The scope essentially describes the code-wise accessibility of the member.