You must safeguard against timing problems.
It is very likely that your frame will load completely before the iframe
does.
In that case, you cannot get the OnSelectionChanged method reference.
You can add an "onload" to the iframe, but it is still possible that it
will break, because the internal frames do not load in the expected order.
A simple fix is to wrap your "InitDocument" with a timer.
Also, using the "frames[0].frames[1]" is relying on the order of your
page, and the order of the viewer frames.
A more reliable method, is to use the ID if the frame element, and then
use the built-in method GetMapFrame().
I have applied the above to your example:
<!-- Javascript part -->
<script type="text/javascript">
var mapFrame = null; // A reference to the map frame
var originalMapFrameOnSelectionChanged = null // storage for the
original onSelectionChanged function
function OnSelectionChanged() // when something is selected on the map
{
alert('Your handler works perfectly');
originalMapFrameOnSelectionChanged();
}
function InitDocument()
{
var win = document.getElementById('viewerFrame');
if (win.contentWindow) //FF returns the actual tag, IE returns
the iframe
win = win.contentWindow;
mapFrameRef = win.GetMapFrame();
originalMapFrameOnSelectionChanged = mapFrameRef.parent.OnSelectionChanged;
mapFrameRef.parent.OnSelectionChanged =
OnSelectionChanged;
}
function RetryInit()
{
if (mapFrame != null)
return;
try
{
InitDocument();
}
catch (e)
{
mapFrame = null;
}
if (mapFrame == null)
window.setTimeout("RetryInit();", 500);
}
</script>
<!-- HTML part -->
<html>
<body>
<iframe id="viewerFrame" frameborder="yes" width="100%" height="60%"
src="
src="../mapviewernet/dwfviewer.aspx?SESSION=<%=sessionId%>&WEBLAYOUT=<%=webLayout%>""
onload="RetryInit()"></iframe>
</body>
</html>
Regards, Kenneth, GEOGRAF A/S
Kimmo Kotajärvi skrev:
Here's my solution (simplified):
<!-- Javascript part -->
<script type="text/javascript">
var mapFrame = null; // A reference to the map frame
var originalMapFrameOnSelectionChanged = null // storage for the
original onSelectionChanged function
function OnSelectionChanged() // when something is selected on the map
{
alert('Your handler works perfectly');
originalMapFrameOnSelectionChanged();
}
function InitDocument()
{
mapFrameRef = frames[0].frames[1];
originalMapFrameOnSelectionChanged =
mapFrameRef.parent.OnSelectionChanged;
mapFrameRef.parent.OnSelectionChanged =
OnSelectionChanged;
}
</script>
<!-- HTML part -->
<html>
<body onload="javascript:InitDocument()">
<iframe id="viewerFrame" frameborder="yes" width="100%"
height="60%" src="
src="../mapviewernet/dwfviewer.aspx?SESSION=<%=sessionId%>&WEBLAYOUT=<%=webLayout%>""></iframe>
</body>
</html>
So, body onload calls InitDocument which registers the new
OnSelectionChanged event handler. The new handler only pops up a
dialog box and then calls the old function. The MG Viewer is embedded
in an iframe.
------------------------------------------------------------------------
*Lähettäjä:* [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] *Puolesta *Tanja Suikkanen
*Lähetetty:* 28. huhtikuuta 2008 14:10
*Vastaanottaja:* mapguide-users@lists.osgeo.org
*Aihe:* Re: [mapguide-users] OnSelectionChanged in AJAX viewer?
My map is embedded in my own page.
When a user selects one or more features on the map, I want my own
function to be executed.
But doesn't parent.parent.mapFrame still get me the map frame..?
And this works but only when I click some button.
Tanja
*From:* Kenneth, GEOGRAF A/S [mailto:[EMAIL PROTECTED]
*Sent:* 28. huhtikuuta 2008 13:57
*To:* [EMAIL PROTECTED]; MapGuide Users Mail List
*Subject:* SPAM-LOW: Re: [mapguide-users] OnSelectionChanged in AJAX
viewer?
Are you issuing the script from a command?
If you want to do this all the time (regardless of what the user has
done), you must load the script with the solution.
If your map is embedded in another page, you can load the script
there, and change "var map = parent.parent.mapFrame;" to point to the
correct frame.
If it is just the basic layout, you can try to put it in the page that
loads in the taskpane (but beware that the document gets unloaded if
the user navigates).
As a last resort, you can embed the script in the viewerfiles.
In case you can use the embedded map approach, you should place the
following line after the "try {":
map = document.getElementById('<insert iframe/frame id>').GetMapFrame()
Regards, Kenneth, GEOGRAF A/S
Tanja Suikkanen skrev:
Ok, I sent my code snippet earlier today, but here it is again.
I got this example from
http://trac.osgeo.org/mapguide/wiki/CodeSamples/JavaScript/AJAXViewerEventHooking.
var map = parent.parent.mapFrame;
var origOnSelectionChanged = null;
function MySelectionHandler()
{
origOnSelectionChanged();
var selCount = map.GetSelectedCount();
if(selCount > 0)
{
My function() {}
}
}
window.onload = function() {
var timer;
var watch = function() {
try {
if(map.mapInit) {
clearInterval(timer);
origOnSelectionChanged = map.OnSelectionChanged;
map.OnSelectionChanged = MySelectionHandler;
}
}
catch(e) {
}
};
timer = setInterval(watch, 200);
};
Window.onload function is executed only, if I press a button.
I want to have the functionality I was telling you about without any
button clicks.
Please ask if I don't tell you enough.
Tanja
*From:* Ivan Milicevic [mailto:[EMAIL PROTECTED]
*Sent:* 28. huhtikuuta 2008 12:04
*To:* [EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>; MapGuide Users Mail List
*Subject:* RE: [mapguide-users] OnSelectionChanged in AJAX viewer?
Feature doesn't get highlighted?
Of course that you can add this functionality in your own code, the
logic is same. Allwas call mapFrame functions (via JavaScript) or
count selection from C# or PHP.
If you want to get some help over here, be more specific.
Ivan.
*From:* [EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>
[mailto:[EMAIL PROTECTED] *On Behalf Of *Tanja
Suikkanen
*Sent:* Monday, April 28, 2008 10:46 AM
*To:* mapguide-users@lists.osgeo.org
<mailto:mapguide-users@lists.osgeo.org>
*Subject:* RE: [mapguide-users] OnSelectionChanged in AJAX viewer?
Ok, now it worked but some functionality had been removed?
When I first select a feature, everything goes fine but when I select
another feature, that doesn't get highlighted...
Also I wouldn't like to change the original files, just add my own
functionality in my own code files.
But thanks anyway!
Tanja
------------------------------------------------------------------------
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