iOS Notifications

Xojo Cloud can function as an Apple Push Notification system (APNs) for handling iOS push notifications. This works with Xojo and non-Xojo iOS apps. All Xojo Cloud servers are pre-configured to send remote notifications. Unlike many other cloud hosts, there is no extra charge for this feature nor is there any limit as to how many notifications you can send.

To send remote notifications from your iOS app you’ll need to go to the Apple Developer website to do these tasks:

1. Add the Push Notifications feature to the App ID.
2. Generate an Apple Push Services certificate.

In Xojo you need to enable the Remote Notifications entitlement for your app in the Capabilities section of the iOS Build Settings Advanced tab.

The final step is to upload your Push Services certificate using the Xojo Cloud control panel.

With super-easy access and no limits for notifications, Xojo Cloud can serve as a great APNs for handling your iOS notification needs.

Database Servers

Most desktop apps use a database of some kind and many are client/server database apps that talk directly to the database server. With Xojo Cloud you can host PostgreSQL or MariaDB/MySQL database servers and connect to them using an SSH tunnel for security purposes.

Setting up a database server on your Xojo Cloud is as easy as checking a box in the control panel.

You can turn on PostgreSQL or MySQL/MariaDB. If your Xojo Cloud server is large enough you could even do both.

If you want to access a database on Xojo Cloud from a desktop app, you will have to enable the SSH Tunnel and then connect to the tunnel from the computer. An SSH tunnel is a secure connection between your computer and another (in this case your Xojo Cloud server) which is used for transmitting data on a specific port. In essence, it creates a private connection through the internet which allows you to see into your server on the other end and connect to a particular service there.

To create a tunnel between a computer and your Xojo Cloud server, you first need to turn on the tunnel capability on your Xojo Cloud server. Go to your control panel and click the “SSH Tunnel” checkbox. You will be presented with a generated username and a password which you will use later for establishing the connection.

On macOS and Linux, you can use a terminal command to access the tunnel (replace username and ipaddress as appropriate; you’ll be prompted for the password).

Use this command to tunnel to PostgreSQL:

ssh -L 5432:localhost:5432 username@ipaddress -N

Use this command to tunnel to MySQL:

ssh -L 3306:localhost:3306 username@ipaddress -N

If you are using Windows, you will need to use an external app such as PuTTY. There are a number of tutorials available on the internet, just put “putty ssh tunnel” into your favorite search engine.

With the tunnel in place you connect to the database as if it were local to the computer. This works with anything, not just Xojo apps.

SFTP

Xojo Cloud offers SFTP (Secure File Transfer Protocol) for file transfer. SFTP is a secure variant of FTP which transmits files over the internet using strong encryption. That way you don’t have to worry about anyone intercepting your username and password or your files as they’re sent to or from your server.

When choosing a client, keep in mind that SFTP is different than FTPS or FTP w/ SSL. They are not interchangeable with one another.

Once you enable SFTP in the Control Panel, you’ll be presented with a dialog showing a generated username and password.

You can now connect using your favorite SFTP client. If you don’t have one, there are a number of free and paid options available including:

• ForkLift
• Transmit
• FileZilla
• CyberDuck

Having a place to store files online is always handy and can be useful when needing to share files with others without having to rely on services such as DropBox.

Web Services

OK, a web service is technically a Xojo web app but it is really an API that is meant to be used by other apps, often desktop or mobile apps. Since a web service doesn’t have any actual UI, you don’t really need to learn how to use the majority of the Xojo Web framework.

Instead you basically add code to the App.HandleURL event to route web service API calls to do specific tasks and then return the results, usually as JSON for the client app to handle.

A web service can be a great way to consolidate code that will be used by desktop and mobile apps, for example.

For example, you could create a Web Service that talks to a database server (such as one of the ones available in Xojo Cloud itself). Your Desktop and Mobile apps can use the same web service to work with the database. All your database-specific code lives in the web service and the client apps make requests and display results.

This is a very common design pattern these days and is a necessary one if you want a mobile app to talk to a database server.

If you want to learn more about web services, here’s a fun webinar to check out:

Learn more about Xojo Cloud today. Xojo Cloud servers start at $49/month, custom servers with more RAM, storage, and virtual CPUs are available. The best way to host your Xojo web apps is so much more than just hosting web apps!

Paul learned to program in BASIC at age 13 and has programmed in more languages than he remembers, with Xojo being an obvious favorite. When not working on Xojo, you can find him talking about retrocomputing at Goto 10 and on Mastodon @lefebvre@hachyderm.io.

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Xojo Cloud is optimized for Xojo applications. It is specifically designed to provide the best possible performance and stability for Xojo web applications. We optimize Xojo Cloud for performance, so your web apps will run smoothly and seamlessly. You can even monitor server stats from within the Xojo IDE.

Xojo Cloud is focused on simplicity and ease of use and requires zero configuration. Designed with the Xojo developer in mind, Xojo Cloud’s Control Panel makes it easy to deploy and manage web applications. Purchase a server, open a web project in Xojo and click Deploy to upload and install to Xojo Cloud. Not just for web apps, Xojo Cloud includes Apple Push Notification server (APNs) support for your iOS apps. Set up SSL, PostrgeSQL, MySQL, SFTP and a SSH Tunnel with a click in the Xojo Cloud Control Panel (the Control Panel itself is a Xojo web app). The administration of a web server is a significant and constant task; Xojo Cloud allows you to leave that behind and focus on your projects.

We take security very seriously. Xojo Cloud offers advanced security features to protect your data from cyberthreats, including a smart firewall, intrusion and hacking detection and Security-Enhanced Linux. Unlike most hosting solutions that provide little to no security, each Xojo Cloud server is built with our state-of-the-art, industrial-strength, multi-tiered security system woven into its very core. 

Additional features and benefits include daily automatic backups, load balancing and support from the Xojo team. With nine global hosting locations, you are able to host your Xojo web applications close to your users, for speed and an ideal overall experience.

In addition to the standard options, Xojo Cloud servers with more RAM, storage and Virtual CPUs are available. Contact customer support for details about personalized plans. 

Whether you are a seasoned Xojo developer or just getting started, Xojo Cloud provides an intuitive and user-friendly hosting solution for Xojo web applications. Today is a good day to start using Xojo Cloud, visit our website to learn more or see the Xojo Store to pick your package and location.

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First, in order to deploy a web app you’ll need a way to access the remote server using the Terminal (macOS) or through the Command line, also a way to create and/or modify several files, and to copy files from your local computer to the remote server using (S)FTP.

Note: While we are using the “root” user for all the operations to keep the tutorial as short as possible, including files/folders/directories creation/edition and also for launching the web app, you’ll probably want to create a specific user with the proper privileges/group configuration for this. As we all know, you don’t usually want to run anything as the root user!

Though this tutorial is focused on the deployment aspects of a web app, we’ll first create a very simple web app in Xojo. Feel free to use a web app of your own. At the end of this tutorial, you’ll find deployment of more complex web apps can follow the same basic principles.

1. The Web App

This very simple app will display a message when the button is clicked.  Start the Xojo IDE and choose Web from the Project Selector window:

Click on the WebPage1 item displayed in the Navigator to access the webpage Layout Editor.

Next, drag a button from the Library panel and drop it anywhere on the Layout Editor.

With the button still selected, add the Pressed Event Handler and type this line of code in the Code Editor:

MessageBox "Hola Mundo"

The classic “Hello World” en español, this is everything the web app will do.

2. Setting the Deployment Options

Click on the Shared option found under the Build Settings section in the Navigator. Next, enter 9000 as the port under the Build Settings section in the Inspector Panel.

Note: Adding the port is not required at this time because the port can be assigned when running the app once it is deployed to the server.

3. Compile the Web App

Make sure to choose the Linux checkbox in Build Settings. Then, select X86 64 bit from the Build popup menu in the Inspector Panel.

Next, click on the Build button in Xojo’s IDE toolbar. Once the app is compiled, you’ll get a Folder/Directory with the following items inside:

This is the folder you will copy to the server. I’m using the Cyberduck app on macOS but you can choose any method you like.

4. Copying the App Folder to the Server

Make sure to copy the folder with the compiled app to the /var/XojoApps path on the server (you’ll need to create that folder/directory first). Once all the files have been copied, make sure to set 750 as the privileges value for the folder and files (choose the option to apply these recursively to all of them).

5. Installing Nginx

If the server doesn’t have Nginx already installed, install it now. Nginx is a light web server which provides more performance when compared with Apache (that is, it is able to serve more requests per second, among other improvements).

To install Nginx, access the remote server using SSH:

> SSH root@xxx.xxx.xxx.xxx

Once the new session is open, type the following commands to install Nginx:

$ sudo apt update
$ sudo apt install nginx

6. (Really) Basic Firewall Configuration

Let’s tackle the firewall. It will need to accept incoming connections from Nginx. Nginx registers itself as a ufw service during its installation. In order to simplify the deployment example, use the most restrictive option allowing only web traffic from port 80:

$ sudo ufw allow 'Nginx HTTP'

Type the following command to verify the changes:

$ sudo ufw status

The output should be similar to this (in my case access from SSH and 8080 ports are also enabled).

Note: This tutorial does not discuss web security which in the overwhelming majority of cases should be a paramount issue and not ignored. Securing a server is a very complicated process which is why we take care of the for you with Xojo Cloud.

7. Creating a New Nginx “block”

Once Nginx is installed, Ubuntu automatically starts this process, so the web server should be active already. Test this by typing:

$ systemctl status nginx

The output  should be similar to this:

Once the server is running, create a new server block. Think about this block like the virtual hosts on Apache. They will encapsulate the configuration details and will allow hosting of more than one domain on the same server.

Nginx loads these configuration files from the /etc/nginx/sites-available path. Create a new file using the nano editor:

$ sudo nano /etc/nginx/sites-available/XojoDemo

Next type the following block in the resulting new document:

server	{
listen 80;
listen [::]:80;
root /var/XojoApps/XojoDemo;
index index.html index.htm index.nginx-debian.html;

server_name xxx.xxx.xxx.xxx;

location / {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Host $http_host;
proxy_pass http://127.0.0.1:9000;
}
}

Replace xxx.xxx.xxx.xxx with your server IP address or the server domain (DNS record, if you have one pointing to it). We are instructing Nginx to redirect the traffic from port 80 to 9000 where our web app will be listening.

Save the file and exit nano. Next, enable the file by creating a link from the file to the sites-enabled directory where Nginx reads the configuration files:

$ sudo ln -s /etc/nginx/sites-available/XojoDemo /etc/nginx/sites-enabled/

Finally, check for syntax errors in the Nginx configuration files:

$ sudo nginx -t

If everything is Ok, then reload Nginx so it reads the configuration files again and applies the changes:

$ sudo systemctl restart nginx

8. Executing the Xojo Web App

It’s time to start our Xojo web app and test the access from the web browser of your choice. Change the current path to the one where you copied the web app. In this example:

$ cd /var/XojoApps/XojoDemo

Next, start the app by issuing the following command:

$ ./XojoDemo --port=9000

Open a new window/tab in the web browser and enter the IP address/web domain pointing to the web server. There is the web app up and running:

Congrats! Now for the harsh truth. This way of executing web apps is not ideal. Because it started from the SSH session on the server, if we exit or interrupt the SSH connection, the web app will exit and won’t be accessible anymore for anyone. This problem also results in a 504 Gateway Time-Out page served by Nginx:

In order to fix this problem, create a Service.  A service will allow the app to run without any intervention, even if there is a server interruption, for example, if the server is restarted or the app crashes.

9. Creating a Service

Type the following in the current SSH session:

$ sudo nano /lib/systemd/XojoDemoApp.service

Next, type the following snippet of text in the new, opened document (make sure to save the changes once you exit nano).

[Service]
Type=simple
Restart=always
RestartSec=3
User=root
ExecStart=/var/XojoApps/XojoDemo/XojoDemo --port=9000
[Install]
WantedBy=multi-user.target

Now that you have exited nano, and with the new service created, activate it with the following commands:

$ sudo systemctl enable /lib/systemd/XojoDemoApp.service
$ sudo systemctl start XojoDemoApp.service

Get the service status by typing the following command:

$ sudo systemctl status XojoDemoApp.service

You should get an output similar to this:

Now, you can be confident that the Xojo web app will be running even if you close the current SSH connection with the remote server and that it will restart even if the remote server is restarted or the app crashes.

If all of this seems more complex than you care to manage, Xojo Cloud is the easy, powerful and secure way to deploy web apps. Xojo does not provide support for configuring your web server for use with Xojo web apps. To read more about deploying Xojo web apps, visit the Xojo Docs Web Deployment Overview and the Web Deployment Details pages.

First, expand the SSH tree in the categories list and select tunnels.

Add a new forwarded port, here we are using port 5432 for Postgres, but you could also use 3306 for mySQL.

Press the “Add” button to save the forward and tick the “Local ports accept connections from other hosts” checkbox.

Select the SSH tree and tick the “Don’t start a shell or command at all” checkbox. This is the bit missing from the Windows native SSH client.

Select “Session” at the very top of the categories list and enter your Xojo Cloud IP address along with a session name and Save so you’ll have this configuration available to you next time.

Now you can open the connection where you will be prompted for your SSH Username (dbadmin) & password.  If this is successful, you will be left with a terminal window that appears to do nothing – leave it open until you want to disconnect.

Once the tunnel is established you can use localhost as the host address of your Postgres or MySQL database. 

Wayne Golding has been a Xojo developer since 2005 and is a Xojo MVP. He operates the IT Company Axis Direct Ltd which primarily develops applications using Xojo that integrate with Xero www.xero.com. Wayne’s hobby is robotics where he uses Xojo to build applications for his Raspberry Pi, often implementing IoT for remote control.