This is how to create a hello world application in DG3.

When you start DG3 the first time it will create a directory in you personal documents folder where all of you web applications will be stored. DG3 development is all about creating text files in an open format and structure, so anything created in the Designer can be viewed and read in the folder structure created in your DG3Apps folder. Each project get it's own folder based on the name you give when creating it, so if you create an application named AllINeed, all files for that opplication can be found and zipped down in YourDocumentsFolder\DG3App\AllINeed. All DG3 based products work this way. Moving an app from one computer to the next is just zip the folder and unzip it in the folder on the new computers DG3 application folder. Backup can be done in the same way.

The first application

To create a working Hello World DG3 application is done in a few simple steps. First launch DG3 and select Create New from the Welcome screen. When started the first time, this is the only option working. Later the created application will show up under Open a recent item an can be opened directly from that list.

The next step is to give the application a name. 

You should only use English letters and numbers (for now) in the name as this will also be the name of your directory. DG3 supports Unicode letters in all levels, but the PRISM database module is ANSI when it comes to names and formulas. Is is also a smart move to avoid spaces in any names in DG3 as you probably will use these as URL parameters and filters when you start to make advanced applications. This will happen sooner rather than later.

Make it a habit to check create repository, as you will need tables with data during application application development. The only reason not to create the repository are if you already have a DfW 8 application you want create a web application on top.

Now you are ready to make you first page holding the obligatory Hello World!. Right click the Page element in the Page Browser and select New page.

Give it a name that describe what it is. No spaces in page names as that do not work well in urls. DG3 will strip them away before creating the url used for accessing the page, but it is better to be able to see what the name will be based on the page name, so just do not use any.

And then it is just to start typing what ever you like ex. Hello World!

Save the page using the save icon and we are ready to launch our first web application in a browser. You have two build in browsers in DG3, the tab called preview at the bottom and the preview icon to the right of the save icon. I prefer the later as the keeps the session between each preview. The drawback with using the preview icon is that you then have to navigate back to the pages by clicking the designer navigator icon on the left side of the screen, but I think it is worth the extra hassle when testing applications with security. The preview  browser can also be found by clicking on the Welcome navigator icon and select the preview tab. The preview browser is a simple webkit (same engine as Safari, Crome and Opera) based browser, but lacks the advanced features for web developers usually found in other modern browsers.

If you want to test you web application in other browser, you can do so by simply copy the URL from the preview browser to the browser of choice. That is yet another reason to use the preview browser instead of Web preview in the page designer as the preview browser gives you the full url and the page preview just give you the relative URL that you have to append to your self. 

When DG3 not works as expected

Even thou DG3 can be used to make proper web applications that are used on live servers, the designer described in this book is called an alpha version. This is due to the crude look on the product and not to do with the rock solid web applications that comes out of the designer when deployed to a server. This means that the designer have rough edges and some times fail to work properly. There are a few simple tricks that usually fix the problem for you and if not, all files are open text files that can be read and edited by any text editor that can read text files.

A chapter in the book is helping you to solve all cases then things not are working as expected. Have a look here.

The different section of DG3 found by the Left side navigator

DG3 is divided into sections taking care of one specific task. Here are a short overview. Later in the book we will visit all of the sections in more detail as we need what they do in an application.

The welcome page navigator icon where you also find the preview browser

The page designer navigator icon where you can create pages, dql etc.

Settings for the application, internal web server console and configuration for modules, snippets, actions, context view, schedules and search

Site layout, templates and robots.txt

Style definitions

Database definition, table design, relationships and internal tables

Transfer data both from and to DG3

Create reports, prints, exports and pdfs

Deploy application to a live application server

Deployment module and live application server setting