Method to disable a button when no connection?

[frankbicknell]

Does such a method exist?

[christappan]

Re: Method to disable a button when no connection?

client-side expressions?

[Davidk]

Re: Method to disable a button when no connection?

Not sure if you're asking about a disable button method or a connection method... or a combo method :)

There's a client-side event named onConnectionChange that I use, along with a this method... {dialog.Object}._getOnlineStatus().

Before I actually do whatever the button does, I call the _getOnlineStatus() method. If offline I adjust the button...

var btnSendEle = {dialog.Object}.getPointer('BTNSENDORDER');
btnSendEle.style.color = "blue";
btnSendEle.innerHTML = "NO INTERNET CONNECTION"

I use the onConnectionChange event to do this...

if (e.online) {
var btnSendEle = {dialog.Object}.getPointer('BTNSENDORDER');
btnSendEle.style.color = "#ffffff";
btnSendEle.innerHTML = "PLACE ORDER"
}

You could add an else to the onConnectionChange to disable the button. I like testing the status as well, though.

[RichCPT]

Re: Method to disable a button when no connection?

I Thought I'd throw this in.....

There is another useful function to help simulate being on or offline, which is especially important if you are developing on a laptop (like on the road, or say in the air going to a developer conference) and your computer does not have an Internet connection. That function is:

{dialog.object}._setSimulatedOnlineStatus(simulateMode)

where simulateMode = "on", "off", or ""

In the UX, if you start typing that command into a JavaScript window it will bring up the context sensitive help, if you are on a new enough release. Sending an empty string to the function turns simulation mode off and reverts the ._getOnlineStatus() back to its default behavior.

I don't know if the Grid has the same function.

The ._getOnlineStatus function uses a function of the browser to determines the online/offline state. So, you are at the mercy of the browser to return the correct value. The browser does not understand you might be developing a disconnected application on a stand-alone computer. Sometimes you will want to simulate being online (as you have the database and web server running locally) and other times you will want to simulate really being offline.

[frankbicknell]

Re: Method to disable a button when no connection?

Thanks for the replies. These methods do not seem to work for an android device. I liked the method that you shared David, but I can't get that event to fire. A simple alert yields nothing when I change the connection status. I tried to call the _getOnlineStatus() in the click method of a button but it returns true whether there is a connection or not. So either these methods don't work for an android or I am not using them correctly.

This is the code I am using in the click event of the synchronize button.

if ({dialog.Object}._getOnlineStatus())
{
    {dialog.object}.saveListEdits('LST_SERVICELOG',{rows: 'current'});
}
else
{
    alert('No Internet Connection - please try later');
}

this is in the code in the onConnectionChange event

if (e.online)
{
    var ele = {dialog.Object}.getPointer('BTN_SYNC_LOG');
    ele.innerHTML = "Synchronize"
}
else
{
    var ele = {dialog.Object}.getPointer('BTN_SYNC_LOG');
    ele.innerHTML = "NO CONNECTION"
}

[Davidk]

Re: Method to disable a button when no connection?

I just fired up the app I have this code in on my Nexus 7. Got to the order button... then went to the Nexus 7 Settings and turned off Wifi. Back to the app, hit the order button and my button turned into "No connection".

Then, back into settings, turned wifi back on, back into the app and the button turned back to "Place Order". So all looks good. The Nexus 7 is running Android 4.4.4.

[frankbicknell]

Re: Method to disable a button when no connection?

Thanks for double checking David, I will try again tomorrow. Perhaps it is because my tablets are cellular enabled even though I disconnected the cell connection and wifi. I know I did not have a connection because the synchronize never succeeded and when I refreshed the list I got the page not found message. I am having strange issues with client side events not firing. Could be the way I have my ux structured. Although fundamentally everything is working well.

[frankbicknell]

Re: Method to disable a button when no connection?

I still can't get the event or the method to work. I have tried on a laptop with no connection, my desktop, the tablet. It does not fire.
I can debug the _getOnlineStatus() method but it always returns true. Perhaps I need to take another approach.
I have found that when there is no connection and I press synchronize nothing happens. When the connection is restored I can press synchronize again and the data is synchronized, nothing is lost.
Maybe I can put a timer to check if the record is still dirty after a set amount of time and return a failed message. Does anyone no how long the synchronize attempt runs before it times out, or actually what happens if it is unsuccessful.

[frankbicknell]

Re: Method to disable a button when no connection?

I have made some discoveries about lists with child lists and synchronizing. The only detail view events that fire are in the parent list. Even if I use the method to synchronize a row from the child list. The synchronize row method asks for the id of the list. I thought it would only synchronize that list but instead it synchronizes all lists and fires the events in the parent list. Is that the way it is supposed to work?

Another interesting discovery. When I use the synchronize all method when inserting a record in the detail view of one of the child list it inserts 4 duplicates which is the same number of child lists.

I have to believe that some of these problems are bugs, unfortunately I guess I will have to wait until someone who can send a test case with the same problems reports it to alpha.

The connection methods and events seem to work OK in chrome, not in firefox, however I have some other formatting issues and sometimes chrome just hangs and the lists do not load.

All in all I am still happy with the lists and the way my app is working despite the problems. I am learning about what not to do. The data is safe and stable. My users are starting to get the hang of it. I am sure eventually alpha will fix it.

[frankbicknell]

Re: Method to disable a button when no connection?

I received a message that the multiple record insert problem has been fixed. I have also given Internet Explorer another look and it appears that all of the connection methods and events fire like they should. I have added a notification area to tell the user if there is a connection and I call the _getOnlineStatus() method in the synchronize button click. Ahh finally it is getting real good. Hopefully the issues with firefox can be resolved.
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[gkpurcey]

Re: Method to disable a button when no connection?

Just adding a link to a video by Bob Moore in case someone would like more information on this thread's topic. He does not disable the button, but rather displays a popup message about the server being offline when the button is pressed.

But he also describes in quite a bit of detail how to do some of the online/offline checking when doing a mobile app. He also shows some ways to really improve the customer experience when using an app that can be offline.

Might be of additional help.

https://www.youtube.com/watch?v=1zG-da2Swdk