before you consider portals, you need to take a look at the environment in which you will use that iPad if it is within reach of a WiFi network, you can host the database with FilMaker Pro (up to 9 iPads) or FileMaker Server (many more iPads). If it is not within reach of a WiFi network, is it within reach of 3G or 4G?
If it is not within reliable range of at least a 3G connection, then you'd need to set up some kind of "synch" system for moving data to and from the iPad.
Thank you for your reply.
Definetly Wifi, definetly more than 9 iPads
Maybe around 100 ipads
How would you begin to build the portal?
Then I recommend using FileMaker Server to host your database from a mac or windows computer that meets the system requirements for that product. Your iPads would then access that hosted database as clients of that system.
I doubt that you are really ordering Pizza here given the large number of iPads. The danger of using such an analogy is that I might suggest something that works perfectly well for Pizza but that doesn't meet the requirements of your actual system.
Note also that I am not an iPad user. It would be a good idea to post your questions in the FM GO forum where fellow iPad users can help you out with fM GO specific information.
That said, have you examined the Invoices Starter Solution that comes with FileMaker Pro 12? It won't do exactly what you describe here but the data model--the tables and relationships needed would be a decent starting point and the layouts/value lists/scripts are also a good source of basic techniques and ideas.
Once you have the basic interface working on your iPad, you can take a look at enhancing that set up to work with the graphic interface you have envisioned for your project. And you'll find that there is more than one possible approach to do that. While a portal could be used to list the icons the users tap to select items for their order, a list view of them might also work.
And I will note that the scripting that can recognize multiple taps of the same button as an indication to increase the size or quantity will be a bit complex to set up...
Thank you for your response, I will look into the invoices example.
I appreciate your help.