I am using the platform Ushahidi Web-2.7.3 , see: http://ti5.net.br/provedorlegal.com.br, and when I zoom in beyond a certain level, the clustered markers disappear from the map. I also tested this on an older version of a site, see: http://movimentofichalimpa.org/mapa, where the clustered markers do not disappear on zooming in, but just become ungrouped, as is normal with a cluster strategy. How can I make the markers remain on the map when zooming in?
Ushahidi actually uses OpenLayers under the hood -- the images may come from Google, but the Javascript library is pure OpenLayers. These markers are actually generated by adding what is known as a context to the style attribute of the OpenLayers.Layer.Vector and an associated Cluster.Strategy. There is a good example of it working properly here: OpenLayers cluster example and if you look at the Javascript source you will see how it is done: view-source:http://dev.openlayers.org/releases/OpenLayers-2.13.1/examples/strategy-cluster-threshold.html by defining a radius in the context of the styleMap.
The reason that your example isn't working is that there is actually a script error being triggered, which is stopping the clustering/styling from being performed. The styles are defined in the file ushahidi.js. If you open a Javascript debugger you will see the error for yourself that is firing before the ushahidi.js functions are called to determine the number of features in the cluster and therefore the radius of the markers.
The actual error is http://ti5.net.br/provedorlegal.com.br/index.php/json/cluster?s=1401591600&e=1404183599&z=9, but I have no idea why, as the OpenLayers is the minified version which is very hard to debug. You might find moving your application to OpenLayers directly will help, as it will be easier to debug, and it also works on mobiles, which I know is one of the reasons people like to use Ushahidi.
Related
I'm trying to integrate my own markers as pointers on my map. The defaults of circle, rectangle diamond etc... are not what I need and I'm looking for arrow symbols instead. Ideally the popular Microsoft wingdings arrows. I'm surprised simple arrows are not on the default list, I'd thought there would be many a need to indicate a rise or fall with any numeric data on a map.
I would like to solve this with an expression to force an arrow icon as a marker, can this be done by using it's character code etc..? I'm using SSDT to design the report.
Alternatively I'll just have to do this in paint and upload via the image import.
Food For Thought
I see they've done a great job in making the map process easy to set up, but when it comes to customisation from the norm it is extremely difficult.
TechNet: Understanding Marker type Rules:
http://technet.microsoft.com/en-us/library/ee240825.aspx
As you can see from the link (Which is one example as not to swarm this post with links) Microsoft make no mention of image upload or Expression input for maps. This I find is one example, the maps are great, but I feel it's difficult to get documented resources to further customise my report.
You'll need to use an image of an arrow for your custom marker, and you will still be able to change other attributes of it (size, transparency, etc).
If you use a custom image marker, you may run into problems where Visual Studio fails to render the map in design mode from time to time - it's incredibly annoying, so I find it best to drop in the custom images as the very last thing I do when building a map (just use a circle marker or something in the interim).
This is driving me crazy. I've been developing some simple embedded Google Maps such as the following:
http://publicworks.snoco.org/rdclosures/snocordclosuregmaps.html
This map in particular has several kml overlays but one of them is no longer displaying the custom placemark icons I had developed and specified. The problem KML layer is this:
http://publicworks.snoco.org/RdClosures/SnocoRdClosures4Gmaps.kml
Some time in the last few months, the custom symbols stopped displaying and have been replaced by the default placemark symbol. If you open the KML file in Google Earth, it displays properly. The KML file does validate using KmlValidator.
Through my searches on here, I saw a suggestion about using definitions at the top of the KML file and then using within each Placemark. I made that change to my KML but it did not appear to make any difference (the custom icons are still not displaying).
I realize that KML files get cached on Google's end so if you look at my javascript code, I'm using the dummy parameter trick with my KML URL path to force a refresh of the layer. The other thing I will note is that the content of this KML is not static and it frequently changes.
Any ideas? Because I'm stumped!
THANKS!
Steve
Agreed with fragileninja that something is happening with your images between your server and Google's. The usual suspects are timing out and 404s (or other server errors).
Since the KML layer is actually being rasterized to tiles on Google's servers, the request has a relatively short timeout so the tiles aren't delayed from being sent to the browser. If the icon images aren't returned in that time, usually Maps will render using the default icon (as it's doing here). However, I also have no trouble getting the icons to work when I host them on my own server, and I don't see atrocious loading times when I access your icons directly, so it is strange.
It's possible that your servers are taking a longer than usual time to respond to Google's servers specifically, or even that they're returning some HTTP error to them instead of an image.
Can you check your server logs to see if you can see the requests and if they're returning as expected?
Finally, if there's no problem there, I would suggest filing a bug on the Maps API issue tracker. Make sure to pick the appropriate template from the dropdown list (you might also consider making a simpler test case, like just using your KML file with the KmlLayer example from the docs) . If you do end up filing a bug, please link it here and I'll make sure it's looked at.
It's something to do with how your server is serving up the images. If I host the icons on mine, it works fine, and your other KML files are using icons from maps.google.com, which also works fine.
Since it works in GE, I'm guessing maybe your server is sending the wrong MIME type or something along those lines. I checked with curl and everything looks fine though, so I'm afraid I can't offer any more details than that. Hopefully this helps get you in the right direction. Good luck!
So this might be a bit tricky to demonstrate, since the problem only appears occasionally and unpredictably--hopefully the problem shows up when you view this question (or, alternatively, has stopped appearing altogether!).
We have a Google Maps implementation on our site that displays paginated search results on a map. The current page's results appear as regular Google Maps markers (with custom icons--these work fine), but the other search results appear as smaller markers in a KML layer. An example:
http://www.redflagdeals.com/in/verdun/map/
The large markers are squarish pin images; the small markers are coloured dots. Blue and purple markers/dots simply refer to different types of content. In the KML file, we've specified two Styles, one for each content type. Other than the Icon reference, which points to the different pin images, the two elements are exactly the same. Here's an example generated KML file for reference:
http://www.redflagdeals.com/in/verdun/map/?do=map_kml&longitude=-73.56895400000002&latitude=45.457064&order=deal_price&dir=asc&category_filter=0&content_filter=0&tag_filter=0&keyword=&page=1&show=deal%20coupon
Most of the time, our map shows the large and small markers perfectly. Occasionally, though, some or all of the small pins show up without the custom icons, instead reverting to the generic blue Google marker image. Today, the custom minipins that show up in blue are broken, while the purple ones are all fine. Other times, both the blue and purple ones are broken.
The problem usually fixes itself, leaving us clueless as to the cause or the solution. The only theory I have is that we use a CDN to host our marker images, and occasionally we push a new version to the CDN while updating all the filenames simultaneously (as we have CDN version numbers in the URLs for our images). Maybe it's possible Google is requesting one or both of the small pin images right when we're pushing a new CDN version, getting a 404, and giving up immediately. But that would mean Google caches the KML images (or lack thereof) for quite a long time. Other than that, I have no ideas.
Is there anything we can do to prevent this problem from cropping up in the future?
see this post (Comment #4 specifically) explains caching of custom markers
http://code.google.com/p/gmaps-api-issues/issues/detail?id=3864
I've just tested this, the result is the following:
I'm sure Google caches both, the KML-file and the marker-images.
(Of course they do, otherwise they must load the files and create new tiles on every single request )
So when you change any marker-image, you must change the URLs of the marker-images inside the KML-file.
You also must change the URL of the KML-file inside your application(otherwise google will not recognize the modified image-URL's)
It's sufficient to append a random parameter to the URLs
I am working on a HTML5 application designed to run a Google map which takes up the entire screen on a mobile phone. For the sake of simple debugging, and perhaps later for legitimate informational purposes, I would like to position some text in the bottom right hand corner of the map, which reports some information, such as the current lat/lng of the user. I have looked through the v3 API, and to the best of my knowledge there's nothing in there to do this. Is there any kind of workaround that would permit this to be done?
Pretty easy really. Add a div as a control. Define an empty div anywhere in your html. Add it as a control, and Maps sucks it into the map display. Then write to it with any DOM functions you wish.
<div id="debug"></div>
-- code goes here --
var x = document.getElementById("debug");
mapName.controls[google.maps.ControlPosition.RIGHT_BOTTOM].push(x);
-- code goes here --
$("#debug").html("debugging info")
Hope that is enough to get the idea across.
In my example I put it in RIGHT_BOTTOM. Other options are here.
Skip
It might be too much work to implement an overlay. For debugging purposes, you're better off using the console logging options from FireBug (or a similar tool). As for the legitimate information, if it's geo-specific, you could use the InfoWindow.
If the data isn't geo-specific, it's probably best displayed outside of the map (You could resize it to be < 100%). Hope that helps.
How do do i add them to my google map ? I've added the marker manager
<script src="http://gmaps-utility-library.googlecode.com/svn/trunk/markermanager/release/src/markermanager.js"></script>
And used the same syntax as in the documentation but they don't show up. The coordinates are correct . Can someone please dumb it down for me . Also does the zoom level have to be to a specific value for me to see them ?
For anyone else in trouble
http://code.google.com/apis/maps/documentation/javascript/examples/index.html
Andrei,
I found the Google Android MapView tutorial to be very helpful:
http://developer.android.com/guide/tutorials/views/hello-mapview.html
It covers creating a basic map application, as well as adding overlays to the MapView, and links to the directions for obtaining the necessary API key. Unfortunately (like a lot of Google's example code, apparently), there are a couple errors in the directions, but I was able to fix those fairly easily.
For example, the definition of your Overlay Class should be:
public class HelloItemizedOverlay extends ItemizedOverlay<OverlayItem>
Which not precisely what the directions say. Eclipse turns out to be very helpful in fixing the problems with this, though.
As to your question about zoom level, it has been my experience that all of your overlays will be displayed as long is your zoom level (or pan state) allows it. If you push them off the screen, they're not displayed, obviously, but not lost either.
R.