PDA

View Full Version : importar una aplicacion de vpf



sanzfelipe
2015-01-01, 15:56
Soy muy nuevo. Quisiera importar a lianja una aplicacion que tengo en VFP

josipradnik
2015-01-02, 07:11
Hi Sanzfrlipe,

I would not recommend thinking about "importing" existing VFP app. VFP has had utility to import from FPD too - because it is expected to be there but was not a way to go. Better to start from scratch in Lianja. Because of your VFP legacy you know much more Lianja than you think. In case of Lianja/VFP the syntax is familiar but devices and platforms have been changed - for which Lianja is ready and VFP is not.

First you need to decide will your app be desktop, web, mobile, tablet or any combination. Your arsenal depends on decision to build desktop or (my term) "non-desktop" app. If your app will be desktop only, you have more options. If non-desktop, you need to design it in the way of "best practice" with standard sections with integrated CRUD, need some javascript coding which browsers understand and you have less options/freedom (for now). Some difficulties in understanding and learning Lianja are here because Lianja is primary for non-desktop app (the future into which our users are pushing us).

In web browsers there are no menu hierarchy we used to in desktop apps. So you need to break down your menus to App Center parts - the apps which consist of pages. Deeper menu levels will be set in page menu(s):


An application is built out of smaller Apps that are grouped together by functional category. These appear in the Lianja App Center. Apps are built out of pages which in turn are built out of sections. Standard built-in sections are those that are in the "Sections" menu. This is how Lianja achieves device independence.

You build Apps using a high level of abstraction... Lianja Apps are built out of pages, pages are built out of sections. There are a wide range of built-in sections including form, grid, calendar, report, canvas, tabview, imagestrip etc..... It's all about a "high level of abstraction" not wasting time with pixel positioning of each UI control.

To build an Application, break it down into smaller discrete Apps and group them together into categories.

Think about how you want the UI to look like, create a page, add sections and relate them together. In other words prototype the whole of your App visually then go back and add specific business logic such as validation, input masks etc.

You use delegates to respond to various actions that occur. Delegates are a scripting language independent methodology.

...to building Web Apps read the Developers guide which explains how you build n-tier Apps that will run on desktop, web, tablet and/or phone. You interact with the UI (presentation level) and code your delegates in JavaScript (the language of the browser) that are called based on various actions occurring. In these delegates you can make calls to server-side VFP procedures (the middle tier business logic). "Standard sections" are data bound. Data CRUD operations are automatically handled by the Desktop/Web/Mobile Client which in turn communicates back and forward with the Lianja Cloud Server.Desktop, Web, Tablet and phone Apps are laid out differently based on their UI personality.

if you want to build an an App that will run in desktop, web and mobile "Best practices" dictate you don't use desktop bound logic nor would you write your delegates in VFP with fat client data manipulation commands; USE, APPEND, REPLACE, SCAN, DELETE etc. Web Apps have a client server architecture. You have to design for it. That's what the Lianja architecture provides you with; A high level of abstraction with pages and built-in sections with various means of navigating between pages of a SPA (Single Page Application).

The whole concept of sections is that they can be looked upon as being a table in relational database terminology. You then relate the sections together just as you would join tables in SQL.

if your existing VFP application has been written with a clear separation between the UI and the business logic then you can call your business procedures from the client.


Somehow I think you are interesting in desktop only. In that case I would recommend this article to start:
http://www.lianja.com/resources/blog/39-coding-tips/190-developing-lianja-custom-section-in-visual-FoxPro

JAOS
2015-01-07, 22:04
Hi Josip,

excellent summary that allows viewing and understand the philosophy of Lianja for those who have used VFP

Jaos

phabio
2015-01-08, 02:04
Hi Josip,
i agree with you.
Import an application does not allow to exploit the potential of the new environment.
If it is necessary only to be executable on other environments, other windows, you can through the virtual machine.

Fabio

K!k3
2015-01-12, 09:19
I want import the application, as it, this time for still using how actually is. But, in future I have to implement more tools (with Lianja), then while I want have the application run in Lianja (but same).

Thanks

Victor Navarro
Barranquilla, COLOMBIA
3008102508
ICQ 279 364 380
Face: +573008102508 (http://www.facebook.com/victorenrique.navarrohoyos)
MSN: eres_un_vago@hotmail.com
Mail: eres_un_vago@yahoo.es (mailto:eres_un_vago@yahoo.es)
Whatsapp: +573008102508
Skype: eres_un_vago (skype:eres_un_vago?chat)
PIN: 7A3F5E60

gontran
2015-01-27, 10:09
veras yo estoy pasando todo un sistema de VFP a lianja , hay que meterle mano si o si , sin embargo los cambios que veo hasta el momento todos me parecen mucho mejores que antes , es mucho mas completo y tiene su gracia , si tendras que cambiar la forma de referenciar los objetos dentro de las formas por ejemplo , sin embargo e smuy amigable y absolutamente programable , ya te contare como me va.

saludos

dianagarcia
2017-08-30, 10:18
Hi josipradnik, you recommend the NO migration from VFP to Lianja, but, in my case, my application is a big and complex one, this application would take me and a full team at least 2 years to program it from the start, for that, start over is not an option for me. Why do you recommend start the application again?

In my case, do you recommend another program or tool to migrate my application?

josipradnik
2017-08-31, 08:35
Hi dianagarcia,

As a VFP programmer I had searched for alternatives to VFP and after all searching I am here.

Today user expectations from applications are very different from those VFP days.
Because of the technology gap I am afraid there is no free lunch in the migration.

Lianja is "cross" on so many levels (Win/Mac/Linux , LAN/internet/Cloud, desktop/web/mobile...)
Choosing among standard sections, custom sections and canvas sections...
VFP/JavaScript/PHP/Python...
Lianja is huge. "Cross..." and "multi" are a plus, but in the same time it is a problem - because of all complexity.

Is Lianja for you - it is a tough question. You need to know where you are headed with your apps.
I suggest you read more about Lianja concept: http://www.lianja.com/community/showthread.php?2880-Answers-Lianja-concept

VFP apps need to be broken down to smaller pieces and to be rearranged a lot for today modern technologies:
App Center (and Categories winthin) -> Apps -> Pages (and Page centers) -> Sections as visual representation of SQL tables...
What about strict separation of server side computing from the client side computing in our old VFP apps?
That is why I do not believe in easy importing on button click.
Do not expect that you will automatically get GUI responsiveness and all to work in web browsers and mobile.

Starting from scratch, at least, we can use VFP syntax knowledge in delegates and progress step by step in converting our apps.
Your VFP knowledge are very valuable and useful here, unlike in some other alternatives where you need to learn completlly new syntax.

Advice? Do begin with some small part of your complex app and see how are you doing.

Josip

pauln
2017-08-31, 21:21
Great comments Josip!
Would represent a lot of us hear, wondering...

Paul