topic Re: Unable to Sync PrePlanned Map Area in ArcGIS Runtime SDK for iOS Questions

Unable to Sync PrePlanned Map Area

RTC — Thu, 19 Aug 2021 00:54:52 GMT

Following the example "ApplyScheduledUpdatesToPreplannedMapAreaViewController" in the arcgis-ios-sdk-samples app, I am having an issue syncing a map. I can download the initial map area and us it without any issues.

The problem:

I try to sync the offline map by using AGSOfflineMapSyncTask and calling the checkForUpdates. No matter what changes are made to the map area in AGOL, the checkForUpdates function returns 'none' It does not recognize that there are updates.

Question:

How do I get the AGSOfflineMapSyncTask.checkForUpdates to recognize that there are updated for the map area?

Re: Unable to Sync PrePlanned Map Area

Nicholas-Furness — Thu, 19 Aug 2021 15:46:40 GMT

Hi. Thanks for the question. Here's what I think is happening.

Scheduled updates are pre-packaged downloads of changes that are created on the server at an interval determined by the web map's owner (perhaps once a day, at 6am, in preparation for mobile users to start their day with all the updates from the previous 24 hours). So, if you make changes to the web map, there will only be scheduled updates available for download after the next scheduled packaging (in the above example, this would be after 6am). In your case, I'm guessing that the next scheduled packaging hasn't happened yet, so Runtime won't see an update when you call checkForUpdates (remember, that just checks for packaged up scheduled updates).

The scheduled updates enhancement to preplanned maps was created to help large mobile workforces efficiently keep their offline maps up to date, but scheduled updates only provide a read-only offline map experience. This page covers scheduled updates in more detail.

If you want to immediately pick up changes made in the preplanned web map, you will need to modify your code to not opt in to the scheduled update workflow and just do a regular sync.

Hope that helps.

Re: Unable to Sync PrePlanned Map Area

RTC — Thu, 19 Aug 2021 19:54:51 GMT

Hello Nicholas,

Thank you for your reply, this is helpful! I did try several tests where I set the update time to a future date/time and then tried to sync the map after that future time but still got the same "none" reply when calling checkForUpdates.

QUESTIONS:

1) Is there a minimum time interval for the updates? For example if I make changes to the map area in AGOL and then set the update time to several hours in the future, should that trigger an update or is there a 24 hour minimum?

2) Would changing the map area's bounds (reshape the area) trigger an update or will only changes to data trigger an update for sync?

3) The Esri example in "ApplyScheduledUpdatesToPreplannedMapAreaViewController" in the arcgis-ios-sdk-samples app assumes the mapview has the map loaded and accessible. Is there an example or best practice for syncing multiple preplanned maps when they are not in use, potentially as a background task?

Re: Unable to Sync PrePlanned Map Area

RTC — Thu, 19 Aug 2021 20:46:38 GMT

Hi,

I'm not sure why this was marked as a solution. The information was helpful but it did not solve the issue. I do not get any updates no matter what the time interval is set to so no solution have been discovered. I also removed the scheduled update enhancement but still no updates are downloaded.

Re: Unable to Sync PrePlanned Map Area

Nicholas-Furness — Fri, 20 Aug 2021 12:07:18 GMT

Hi RTC.

Glad that helped. For your other questions:

~~You don't set a time in the ArcGIS Online interface, merely an interval~~. I'll have to check to see what the minimum interval is but it seems to be 24 hours through the ArcGIS Online interface and the Python API.
I'll have to check on this.
Absolutely, you would still create an AGSMap object pointing at each already-downloaded offline map (you use the AGSMobileMapPackage to re-open a previously downloaded map, see here) and then create an AGSOfflineMapSyncTask for each AGSMap.

Hope that helps.

Re: Unable to Sync PrePlanned Map Area

RTC — Thu, 19 Aug 2021 21:19:48 GMT

Hi Nicholas,

In your reply - "You don't set a time in the ArcGIS Online interface" - Can you clarify this. There is a setting for Time in AGOL, can you explain what this time is for?

Re: Unable to Sync PrePlanned Map Area

Nicholas-Furness — Fri, 20 Aug 2021 12:05:27 GMT

My mistake. I noticed your reply was marked as a solution and figured you must have picked that instead of mine. Thanks for correcting this.

Re: Unable to Sync PrePlanned Map Area

Nicholas-Furness — Fri, 20 Aug 2021 12:10:08 GMT

Apologies. I misunderstood your question about changing the update time to trigger a scheduled updates packaging. My mistake (your question was pretty clear!). I'll have to check with the team to see if this would trigger packaging things up, or if there might be some other way (e.g. a REST call).

Re: Unable to Sync PrePlanned Map Area

RTC — Fri, 20 Aug 2021 17:54:24 GMT

No worries, thank you for looking into this for me!

Re: Unable to Sync PrePlanned Map Area

RTC — Wed, 25 Aug 2021 00:38:40 GMT

Hi Nicholas,

I still have not been able to get the preplanned map area sync to work. I have tried removing the scheduled updates and just run a manual update but it never seems to download the updates. Any ideas on what the issue could be?

How is the sample "canyonlands" map setup in "ApplyScheduledUpdatesToPreplannedMapAreaViewController" in the arcgis-ios-sdk-samples app? The example seems to work but if I replace the canyonlands map with one of my maps, it never detects an update as being available.

Thanks for you assistance!

Re: Unable to Sync PrePlanned Map Area

Nicholas-Furness — Wed, 25 Aug 2021 17:20:34 GMT

Hi.

I've spoken with the team and 24 hours is the minimum interval between updates being packaged up. Changing the packaging time will not trigger another packaging within 24 hours of the last packaging.

As for why a manual sync doesn't get the updates: what are the updates you are making? You need to update feature data in layers in your web map (and of course the services behind those layers need to be enabled for offline use).

Once you've made feature updates in the web map (add/remove/update features) then they will be picked up in an offline map sync.

If you are using scheduled updates for the sync, they won't be picked up until after the next packaging run. If you are not using scheduled updates, they should be picked up immediately.

The canyonlands sample uses an already-downloaded preplanned offline map as its "snapshot" starting point. It copies it into a working folder and opens it. The web map has scheduled packages that were generated after that offline map was downloaded, so they show up as available updates in the sample. Once you have applied the updates to the copy in the working folder, if you were to check again using that working copy, there would be no more updates available. The working copy is overwritten by the "snapshot" copy each time you run the sample.

For your map you need to:

Create a web map with offline-enabled feature layers.
Configure the preplanned map area for your web map and turn on the "Enable scheduled updates" toggle.
Wait for the original preplanned offline map to package up.
Download the preplanned offline map to the device, being sure to opt in to scheduled updates (this should be picked up by default).
Make edits to offline enabled feature data in your web map.
Wait until after the next packaging, which will pick up your web map data edits as a scheduled update package. You cannot bring the packaging time forward for this to force packaging any sooner than 24 hours after step 3.
Call sync using the offline map downloaded in step 4 (and making sure to use scheduled updates).

You can still use a web map that is set up for scheduled updates with regular sync, but you have to ensure the settings when you download the offline map opt out of scheduled updates. Perhaps that's what you're seeing: maybe you downloaded the offline map without opting out of scheduled updates, and then when you sync you're trying a regular sync. That won't work (and I think I misled you there - I wasn't explicit that you need to do this with the download as well as the later sync). You could look at the AGSOfflineMapSyncResult you get back in the sync completion to see if there are errors and look at the errors on each layer to learn more.

Let me know if that helps.

Re: Unable to Sync PrePlanned Map Area

RTC — Wed, 25 Aug 2021 18:18:54 GMT

Hello Nicholas,

Thanks for the detailed response! I will follow your guidelines and do
some more research. I believe my past tests did follow the same
workflow you outlined but now knowing about the 24 hour limit may produce
different results. I will let you know what I find out.

Thanks!

Re: Unable to Sync PrePlanned Map Area

RTC — Thu, 02 Sep 2021 21:11:50 GMT

Hello Nicholas,

I was hoping to get some clarification on a few items. Based on your advice, I ran a few more tests and wanted to confirm that what I am seeing is correct. All my tests are for read-only (download) updates from AGOL, not bi-directional sync.

If the "Enable Scheduled Updates" toggle is enabled (true), updates will package and only be made available at the next scheduled time (24 hours later) even if the map is updated manually by using the "Update" button.
If the "Enable Scheduled Updates" toggle is NOT enabled (false), updates will package automatically at the next scheduled time (24 hours later) BUT if the map is updated manually by using the "Update" button, the updates will be available immediately.
If the Update Scheduled TIME is changed AFTER the preplanned map is initially downloaded, the "checkForUpdate" function will return an indeterminate state. To correct this, the preplanned map needs to be downloaded, not synced, again.
ONLY changes to the data of a feature layer are synced, NOT changes to the map region, adding layers, map style (icons) etc. Is there documentation that details what will/won't trigger an update?

Thanks!