Collector : an offline app not very offline ?

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06-15-2015 08:34 AM
NicolasGIS
Regular Contributor

Hello,

We were very interested into having an offline application to work where no connection is available and for this reason we choose Collector for ArcGIS.

Collector is said to be an offline application but it is only partially true !

Indeed, it needs a connection at the beginning to identify with AGOL. We thought that by not killing the app or not disconnecting from it, it would work. Once again, it is partially true because sometimes it does not require any connection to relaunch the app and sometimes it does and then you are stuck ...

Is there any pattern in the identification process that could help us to anticipate this issue ? As we wanted to use the app in an emergency scenario where no connection would be available, it is a big disappointment.

Any suggestion to avoid this problem is very welcome,

Thanks for your help,

Nicolas

9 Replies
IanKidner1
New Contributor III

The Ohio Department of Transportation has been testing Collector and has determined this to be an issue as well.  The workflow seems to be that you need to sign in and download/sync a map for offline use while an internet connection is available, and so long as the app does not crash, device is not turned off, or the app is not accidentally closed, it should work successfully.  However, if any of those scenarios occur an internet connection is required to gain to the app.  My guess is that it is attempting to verify credentials in ArcGIS Online. 

This is becoming a concern for our organization. 

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NicolasGIS
Regular Contributor

I don't know which authentification you use but here we are using a Web-Tiers one (SAML) for ArcGIS Online and this problem comes from the validity of the token. I got this answer from ESRI support  :

"Collector for ArcGIS is a web based application that although is able to download maps to be used in a disconnected environment, it's not solely meant to be used offline. While having the device on airplane mode for an extended amount of time, you will eventually see that your IDP token is going to expire and Collector will need to re-authenticate in order to stay logged in. This is how web applications are handled, so this is not something that would be specific to Collector - you would encounter it with any mobile application that uses a SAML authentication method".

What we did is set up a protocol to log again at specific hour because as the plan is to be able to use Collector also in an emergency scenario, we have to be able to use it anytime in a disconnected environment.

I am still a bit surprised by this answer because I was able to keep Collector opened for weeks and playing with it but the token is valid less than a day. This is what is a bit frustrating : there is no pattern ...

MiaogengZhang
Esri Regular Contributor

If it is logging you out then here is the logic:

We ask if you are connected.

-If yes then we "log in" so if the token is valid -- we query the portal, find the maps -- or if the maps fail to be queried, we show offline maps only.

-If no then we “log in” and show offline maps only.

Potential issue and Recommendation

Now if connected and the token is invalid we have to refresh that token. If the refresh fails that will trigger a logout.

Potentially the refresh may fail if the network connectivity is intermittent. This is a failure of the cell network. What I would recommend is that you put the device into airplane mode or disable cell if that is the case.  If you have the network off you are going to eliminate the potential issue and save your battery usage without continual search for cell signal. If in airplane mode or no network we will prevent you from logging out of the app.

Can putting device in airplane mode solve the issue for you?

NicolasGIS
Regular Contributor

Thanks for these explanations.

I find your explanations pretty logical and was already playing with airplane mode so as to be sure that Collector does not check the token. So this is the theory.

Now in practice, I will explain you why I said that there was no pattern.

For example, I left opened Collector during 4 days and did not touch the Ipad. Then, I came back at my office, I checked that Wifi was on, I refreshed the maps of the application and it did work ! No logging out ! I even killed the app, opened it again , then there was written "Connexion en cours" (something like "Signing in" in English) and Collector did open !

So the token has expired and the refresh should have failed but it worked.

I have other experiences when it logged out but most of the time it does not logged though it should.

Have I missed anything ?

Thanks again for your help,

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MiaogengZhang
Esri Regular Contributor

When Collector is connected to network and the token is expired, Collector will try to refresh the token automatically. Collector will open and query online maps, .etc. If the network connectivity is intermittent, the refresh token will fail and it will trigger the log-out.

If there is not network connection (airplane mode as an example), then we “log in” and show offline maps only.

Does it make sense to your experience?

NicolasGIS
Regular Contributor

So Collector does try to refresh the password automatically. That is interesting. So there is no need to play with the validity period. Thanks for this precision because I had not understood that.

Regarding the network connectivity intermittent, I am a bit sceptical because so far all the tests have been done inside right next to the AP. But I will pay more attention to that from now on.

Thanks

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SPESGIS
New Contributor

I am also having this issue with the "offline" capabilities of collector.

I'm trying to run a test to see if the accuracy of using IOS devices is just as good as our Garmin from 5 years ago so i would need the Offline capabilities.

I will try the airplane mode but even if that works that negates the point of using the device as a gps. (I am using an Iphone). Surely, with Airplane mode on you would not get a signal for GPS and 3G that is used for accurate location recording.

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MichaelDavis3
Regular Contributor

iPhones do use the cell network to speed up the process of determining a GPS position, but are perfectly able to do so without any network connection whatsoever.  In our experience iOS devices have been more than adequate compared to a Garmin. 

In some cases a Garmin is still better suited for data collection, and we pretty much always send one out with our field crews for backup purposes and to collect a track.  That said, a Garmin is generally not at well suited for collecting data with expensive attributes, related records, etc...   

You might try turning WIFI and Cellular Data off for your testing rather than activating Airplane mode.

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AlexanderKlausegger
New Contributor II

Hi everbody,

can a statement be given for the period of time the token is valid? If you take your map offline (and go in offline mode), how long can you work with Collector for ArcGIS? How long is the token valid with a connection?

Thanks in advance, Alex.

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