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Screen Navigation Using EDT Eclipse [message #808238]

Mon, 27 February 2012 10:13

yuvaraj g
Messages: 17
Registered: February 2012

Junior Member

Hi,

Please find attached the document detailing the issue encountered while navigating screens. Please share your ideas/comments in fixing the same.Thanks in advance.

Regards,
Yuvaraj

Attachment: EDT_Issue_NavigatingScreens.doc
(Size: 77.50KB, Downloaded 88 times)

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Re: Screen Navigation Using EDT Eclipse [message #808273 is a reply to message #808238]

Mon, 27 February 2012 10:50

Joe Pluta
Messages: 27
Registered: July 2009

Junior Member

Just so you know, Yuvaraj, I can't see the code in your attachment. I just see a couple of placeholder icons.

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Re: Screen Navigation Using EDT Eclipse [message #808391 is a reply to message #808273]

Mon, 27 February 2012 13:39

yuvaraj g
Messages: 17
Registered: February 2012

Junior Member

Dear joe,

Please find attached the code for the two screen handlers.
one is login screen and the other is detail screen about employee who is signing in.

We need to know how to navigate from main screen to the subsequent screen and how to pass parameters to the second screen(in this case we are trying to pass employee userid and name). We also tried delegate function but its giving some error in delegate declaration as below:

// delegate
switchFunction SwitchToPagePart;
error:
"IWN.VAL.3433.e 12/19 The type SwitchToPagePart is not instantiable. The reference to this type must be defined as nullable."

Thanks in advance,
Yuvaraj

Attachment: Screen1.txt
(Size: 4.79KB, Downloaded 76 times)
Attachment: screen2.txt
(Size: 12.59KB, Downloaded 66 times)

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Re: Screen Navigation Using EDT Eclipse [message #808410 is a reply to message #808391]

Mon, 27 February 2012 14:00

Joe Pluta
Messages: 27
Registered: July 2009

Junior Member

Okay, without spending a lot of time in your code, let me tell you my preference: I prefer to use RUIWidgets rather than RUIHandlers for each page. My only RUIHandler is a top level page that swaps between the handlers.

My standard is this. My application handler has as its UI a Box named "ui". The Box has one child, the splash screen. When the splash screen is done, I set the first page:

ui.children = [ page1Widget ];

Then, when I want to change panels, I simply replace the children:

ui.children = [ page2Widget ];

The trick here is that the top page has to do the switching. I do that by using the Infobus. When a page widget needs to switch to another page widget, it sends a message to the application RUIHandler via the Infobus, and the RUIHandler then loads the appropriate widget.

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Re: Screen Navigation Using EDT Eclipse [message #808670 is a reply to message #808391]

Mon, 27 February 2012 21:07

fahua jin
Messages: 58
Registered: July 2011

Member

Hi yuvaraj g,

Please refer to my attached two egl files for the handler navigation sample, hope it can help you.

Rocky

Attachment: H1.egl
(Size: 0.79KB, Downloaded 73 times)
Attachment: H2.egl
(Size: 0.87KB, Downloaded 71 times)

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Re: Screen Navigation Using EDT Eclipse [message #809471 is a reply to message #808670]

Tue, 28 February 2012 18:00

Theresa Ramsey
Messages: 62
Registered: July 2009
Location: research triangle park, n...

Member

Hi,
As Joe recommends, the main way to pass information between handlers is to use the InfoBus, which has publish and subscribe functionality.

The samples, on the EDT Documentation page, can help you learn how to use the InfoBus, plus you can refer to the Help.

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Re: Screen Navigation Using EDT Eclipse [message #809947 is a reply to message #808410]

Wed, 29 February 2012 08:35

yuvaraj g
Messages: 17
Registered: February 2012

Junior Member

Hi ,

We are still not clear with the parameter passing between the handlers. we tried with H1 and H2 source code which jinfahua referred.

please find attached the document detailing the required output we tried to achieve using EGL EDT.

Thanks

Attachment: Error in parameter passing.docx
(Size: 21.71KB, Downloaded 64 times)

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Re: Screen Navigation Using EDT Eclipse [message #809956 is a reply to message #809471]

Wed, 29 February 2012 08:53

Joe Pluta
Messages: 27
Registered: July 2009

Junior Member

Here's a VERY simple paging project. It has three pages, each of which is a RUI widget. It has an initial RUI handler (Init) that shows a splash screen and then shows page 1.

Each page has buttons for the other pages, as well as a back button. Whenever the user switches page by hitting the button, the page widget sends an Infobus message to the init handler. The handler then switches to the appropriate page.

I did make this a little more than just a page switcher. I added a stack of pages which act as a history. That enables the back button, which will go back through the selected pages until it hits the initial page.

Even an example this simple has a lot of design points. For example, I only have one instance of each page. That makes sense on pages with read-only data, not so much with input-capable fields.

Enjoy!

- Joe

Attachment: Paging.zip
(Size: 29.68KB, Downloaded 94 times)

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Re: Screen Navigation Using EDT Eclipse [message #809973 is a reply to message #809947]

Wed, 29 February 2012 09:15

Joe Pluta
Messages: 27
Registered: July 2009

Junior Member

yuvaraj g wrote on Wed, 29 February 2012 08:35

Hi ,
We are still not clear with the parameter passing between the handlers. we tried with H1 and H2 source code which jinfahua referred.
Thanks

Okay, parameter passing is a different topic. So, you want one page to pass a value to another page. The first question is whether this value is persistent or transient. That is, do you want the value to last as you switch from one page to another. If that's what you want, then you need to use a persistent variable which you typically store in the page somewhere. I usually create a library called SessionLib with functions to get and store values.

If not, if you just want to pass the value and forget about it, then you can use either pass it to the second page when you create it (see @EGLProperty) or you could pass it in after the fact by sending an Infobus message.

[Updated on: Wed, 29 February 2012 09:17]

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Re: Screen Navigation Using EDT Eclipse [message #809980 is a reply to message #809973]

Wed, 29 February 2012 09:24

yuvaraj g
Messages: 17
Registered: February 2012

Junior Member

Hi JOE,

Thank you so much for your reply.

Can you please explain more about that, like how to set @EGLProperty....

It will be really helpful for us , since we are struck for a long time in these parameter passing and couldn't proceed further.

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Re: Screen Navigation Using EDT Eclipse [message #810004 is a reply to message #809980]

Wed, 29 February 2012 09:53

Joe Pluta
Messages: 27
Registered: July 2009

Junior Member

IBM has some really good help text.

Click http://tinyurl.com/7vj7nml for general help on extending Rich UI.

And http://tinyurl.com/7r54xqt for detailed information on the @EGLProperty annotation.

Joe

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Re: Screen Navigation Using EDT Eclipse [message #812843 is a reply to message #810004]

Sun, 04 March 2012 06:49

yuvaraj g
Messages: 17
Registered: February 2012

Junior Member

Thank you Joe. now we learnt how to pass parameters between widgets and handlers using Infobus/embedding handler/delegates.

the next challenge what we are facing is , how to pass the same parameters and load the widgets for the consecutive screens. Say for example we have around 6/7 screens. like one parent screen(which is login screen in our case) and multiple immediate child screens and in turn this child screens has many grandchildrens. I need to pass the parameter from parent screen to many child screens and from child screens needs to pass parameters to their grandchilds.

Our observations is, if we use InfoBus, it can able to pass parameters to one level.
for example, we have init screen handler which is a splash screen and three child screen widgets(page1,page2,page3). Infobus passes values from page1 to init or page2 to init or page3 to init. But what we are trying is, to pass parameters from page1 to page2 and from page2 to page3, since our requirement is like navigating(as well as we need to pass parameters)from page1 to page2 ,from page2 to page3 and from page3 to page4.... like that it goes on.

Can you please help us to proceed.

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Re: Screen Navigation Using EDT Eclipse [message #813295 is a reply to message #812843]

Sun, 04 March 2012 23:21

Joe Pluta
Messages: 27
Registered: July 2009

Junior Member

You're getting into a very large architectural area, yuvaraj g. But just as a brief comment I'd say that what you're doing is not passing parameters, but setting session variables. If the init screen retrieves some value that is that is then used in many other pages, your best option is to create a library to hold that information and make it available for your application. I usually end up with a library called SessionLib and a record called SessionInfo. SessionLib allows access to a single instance of SessionInfo that everybody can read and write.

I might be able to put together an example to show you, but not tonight. Laughing

Actually, one of these days I need to put together a suite of example programs that explain some of the basic architectural techniques that work well with EGL.

Joe

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Re: Screen Navigation Using EDT Eclipse [message #815851 is a reply to message #813295]

Thu, 08 March 2012 00:26

yuvaraj g
Messages: 17
Registered: February 2012

Junior Member

Thank You Joe.

We have put all the screens in one handler as different widgets as you suggested earlier instead of keeping seperate screens and setting variables.

This is working fine. Thank you again.

Yuvaraj

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Re: Screen Navigation Using EDT Eclipse [message #897174 is a reply to message #813295]

Sun, 22 July 2012 19:45

Ben Foster
Messages: 4
Registered: April 2013

Junior Member

Joe, I took your reference to architecture as my inspiration to take a stab at piecing together the elements of this topic of page navigation and passing data between web pages to formalize your ideas.

I appreciate you presenting the page navigation scheme and I have incorporated it into the architecture.

As one of the developers with Java and JSF development experience (as well as 30 some years of RPG) we are attempting to usher in the EGL language. Having a uniform method of page navigation and parameter passing from the very start will be an immense help.

Thanks, Joe (and others).

I have put together a web page for our group that presents the pieces required to support the architecture. Since I don't have the required number of messages to present the URL, I can only say that it may be viewed at iseries.egl.wordpress.com. The link is presented on the page presented under the topic of Standard Look and Feel.

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