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
Related
Why doesn't google map z (zoom) parameter work inside the url?
I' ve searched over so I got few solutions for sending zoom parameter in google map url but based on the old posts (stackoverflow) which deal with the zoom level within the url it seems that this functionalities do not work anymore.
I've used the following z parameter but it's not working:
http://maps.google.com/?q=38.6531004,-90.243462&z=12
Below is the link where they have mentioned z parameter for zoom level
link
For those who do not want to read,
this works (z range:[1-20]):
https://maps.google.com/?q=38.6531004,-90.243462&ll=38.6531004,-90.243462&z=3
There is no documentation that covers this problem. However, there are few hacks.
The link that you have provided,
URL (stackoverflow):What parameters should I use in a Google Maps URL to go to a lat-lon?
Will not help you with getting the desired google maps zoom level inside a url
The following examples which have been working for quite a while DO NOT WORK anymore (they work but without getting the desired zoom level)
Examples:
http://maps.google.com/?q=38.6531004,-90.243462&z=3
http://maps.google.com/?q=38.6531004,-90.243462&zoom=3
http://maps.google.com/maps?q=Scottish+Rite+Hamilton+ON&loc:43.25911+-79.879494&z=15
Instead, you can get the zoom level easily by trying the following examples:
https://www.google.com/maps/#38.6531004,-90.243462,9z
https://maps.google.com/?ll=40.7060471,-74.0088901&z=3
(Note: after clicking on google maps you will get a gray marker which appears and quickly disappears)
However the above URL's will not give you a static pinpoint for the specified lat&long.
There is a "hack" on how to get a fixed pinpoint (red marker pin) and that is by giving the q attribute (represents the search query) and the II attribute(latitude and longitude of the map centre point) along with the z (zoom attribute)
Example (with the OP coordinates):
https://maps.google.com/?q=38.6531004,-90.243462&ll=38.6531004,-90.243462&z=3
If you want to change the zoom level just change the value of 'z'.
After searching the web I found that only this website:
https://moz.com/blog/new-google-maps-url-parameters
deals with google maps parameters/attributes/arguments, where things actually still work. If anyone want's more functionalities within the url, then this is the site to check.
Zoom intervals explained (https://developers.google.com/maps/documentation/static-maps/intro#Zoomlevels):
The following list shows the approximate level of detail you can
expect to see at each zoom level:
1: World
5: Landmass/continent
10: City
15: Streets
20: Buildings
This works as of 5 Aug 2018
http://www.google.com/maps/place/<lat>,<lng>/#<lat>,<lng>,<zoom>z
For example
http://www.google.com/maps/place/49.46800006494457,17.11514008755796/#49.46800006494457,17.11514008755796,7z
As of 04/2020 ...."because google is always changing and evolving"
In complement to Eugen Sunic comments above, and an alternative update to the Solution.
When Logged in to google and getting map data from the google generator, it is not the same as copying the URL from the browser window (which my may be manipulated to load different zooms trough the various alterations, html, Css and script tricks).
But in the below, keep in mind that Your address info may need to be part of the google array of database, eg you have some address map info linked to your account, images, business name, etc. or not... maybe just typed in for a quick map search with a pin-point... the later I don't know.
Also the below is not some Google API pay per 1k clicks thing, which is more geared to the commercial development end of google tracking heat maps, etc. So if you just need a simple solution and certain zoom and marker to work..then you might try the below.
When logged in too your Google account (maybe not) and showing your location marker on the map screen...
Choose the zoom detail of the map you want to appear in your web page. eg Whole US, State views, City, Street (by clicking the + or - zoom feature).
Then go to the hamburger menu to the left, and look down the list for "Share or Embed Map" and the popup window should load the same zoom level of the map! Do not try to change the zoom in the popup window feature, it wont work to change the link code but will change the pop up windows zoom of the map. In short, the embedded link code is preset and will not change in the popup.
Above this popup window of the map there will be two options at the top (Share and Embed) button/link selections.
Click on the Embed link/button and it should generate the code for the zoom you previously chose.
Lastly, copy the code, paste it into your web page and TEST!
As far as I can tell, There is no altering this code as the others suggested above, changing(z=3, 9z, etc) as the code is entirely different. But it will allow you to get the zoom you need "if the google code generator or procedure does not change".
But the zoom level was altered and good enough for me when I figured the process out. Changing it to other zooms is another can of code.
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.
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).
Im not sure how but thats the only conclusion I can come to.
Ive been playing around with placing a marker at a distance along a route, I found Mike Willamsons epoly.js and some example files and started to play around with them but for some reason the exact same code doesnt work on my server.
eg
http://www.geocodezip.com/v3_GoogleEx_directions-waypoints_kmmarkersC.html
is a simple example that drops two markers at 2 different distances along the route.
I simply viewed source, copied the entire code and pasted it into an hmtl file on my server, taking care to create the scripts directory and drop v3_epoly.js into it.
As you can see below, my page however does everything except output those 2 important markers.
http://peg-web.me.uk/map/
Am I missing something fundamental?
I know, this forum isnt for the epoly.js add in but Im trying to establish if my problem is more fundamental ie related to javascript itself.
Those marker icons are referenced with relative URLs, copy the icons onto your server, put them in the same relative location to the HTML page and they will appear.
Or change this line in the createMarker function:
icon: getMarkerImage(color),
To (comment the property out):
// icon: getMarkerImage(color),
(that will make them use the default marker icon)
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!