Get latitude/longitude and stop location runtime event

Getting Started Newbie Questions
#1

Hi, I am developing a weather app that gets your current location and display the weather details. The problem at the moment is that when i test the app out on the device, the event.latitude and event.longitude keeps updating too.

I just want to start the app, get the positions once and stop the runtime location event.

Any thoughts?

#2

Hi @contact551,

If you post some of your code, it will help people diagnose a potential solution. As a quick initial consideration, I think you’d just add the Runtime listener, check when you receive both a latitude and longitude, then remove the Runtime listener and process those values that you received.

Take care,

Brent

#3

I noticed this and also noticed somebody highlighting it in the forums a number of years ago - I found that the position of my listener function helped this - upon certain conditions the Runtime:removeEventListener(“location”, listener) just didn’t have any effect.

I’ll dig out my code later and try to help out.

#4

Hi Brett, this is my code:

local lat = nil local lon = nil local locationText = display.newText("", display.contentCenterX, display.contentCenterY, nil, 18 ) local function myListener(event) if event.errorCode then native.showAlert( "GPS Location Error", event.errorMessage, {"OK"} ) print( "Location error: " .. tostring( event.errorMessage ) ) else lat = event.latitude lon = event.longitude if lat ~= nil and lon ~= nil then locationText.text = lat.." "..lon Runtime:removeEventListener( "location", myListener ) end end end Runtime:addEventListener( "location", myListener )
#5

It seems the Runtime:removeEventListener has no effect in here. The vars lat and long keep changing as I walk with the device, but all I want to do is to register the user location when the app opens and then stop. Any ideas?

#6

Hi @contact551,

If you post some of your code, it will help people diagnose a potential solution. As a quick initial consideration, I think you’d just add the Runtime listener, check when you receive both a latitude and longitude, then remove the Runtime listener and process those values that you received.

Take care,

Brent

#7

I noticed this and also noticed somebody highlighting it in the forums a number of years ago - I found that the position of my listener function helped this - upon certain conditions the Runtime:removeEventListener(“location”, listener) just didn’t have any effect.

I’ll dig out my code later and try to help out.

#8

Hi Brett, this is my code:

local lat = nil local lon = nil local locationText = display.newText("", display.contentCenterX, display.contentCenterY, nil, 18 ) local function myListener(event) if event.errorCode then native.showAlert( "GPS Location Error", event.errorMessage, {"OK"} ) print( "Location error: " .. tostring( event.errorMessage ) ) else lat = event.latitude lon = event.longitude if lat ~= nil and lon ~= nil then locationText.text = lat.." "..lon Runtime:removeEventListener( "location", myListener ) end end end Runtime:addEventListener( "location", myListener )
#9

It seems the Runtime:removeEventListener has no effect in here. The vars lat and long keep changing as I walk with the device, but all I want to do is to register the user location when the app opens and then stop. Any ideas?

#10

Same problem here, can’t seem to be able to get lat and lng only once.

#11

I would love to get an answer to this as well. Currently this issue causes unnecessary battery drain. There must be a way around this. Thanks for your help.

#12

It is because you can’t remove a listener from inside a listener. 

try to put your removeListener call in a timer.performWithDelay closure to see if it helps.

 timer.performWidthDelay( 10, -- 10 ms delay, just to "get out" of the listener scope function(e) Runtime:removeEventListener("location", myListener) end )
#13 
local updateLocation = function() local function locationHandler(event) if event.errorCode then print(" ERROR : " .. tostring( event.errorMessage ) ) else print(" LAT : "..event.latitude..", LONG : "..event.longitude) end Runtime:removeEventListener( "location", locationHandler ) end Runtime:addEventListener( "location", locationHandler ) end
#14

Can confirm this is still a bug on all device. The removeEventListener isn’t firing off, other than on the Corona Simulator.

#15

We would need an simple app that shows this problem.  We need a complete sample app (main.lua, your build.settings and your config.lua that’s causing the issue) in a zip file.  Click on the “Report a Bug” link at the top of the page.  When you get the email confirmation, please post the bug # back here as a reference.

Once we see the code, we can help try and figure this out or get it to engineering if it’s a bug.

Rob

#16

Sent in a zip a few days ago and still no email confirmation.

#17

Hi @zv713,

Did you submit this through the official bug/issue report system, or via e-mail?

Brent

#18

Though the official system found in the Report a Bug link up top.

#19

Thank you. You may not receive a prompt e-mail, as we have to prioritize this issue and test it on our side… but it’s logged in our tracking system now.

Brent

#20

I’ve dug through the bug tracker and I don’t see any thing when searching for keywords from this post.  Can you try and re-submit it?  You should get an automated message (not from a human) with the case # in it.  Please check your spam posts to see if it when there.

Rob