Setting map extent to a group of graphics

[SamirGambhir]

Hi,
I am running a query to select a number of polygons based on an intersecting polygon. The selected polygons are contiguous and are highlighted when the query is complete. I am trying to set the map extent to the extent of all these polygons combined together but have been unsuccessful. I have tried suggestions posted on these forums and using samples provided by ESRI but am still unable to get the map to zoom to this area. I have tried creating an array to push graphics inside it. I have also tried creating a polygon feature, a feature set and a graphicsLayer as a container to hold all the selected graphics, but it didn't work. I am using ArcGIS Server 9.3 with JavaScript API. Please help.
(Note: The code below has been extracted from a longer version. It might be missing some braces)

function findPolygonsInExtent(extent) {
      
  var graphics = map.graphics.graphics;     
  var attr =[];
  var items = [];
        var graphic;
  var len=0;
       
  for (var i=0, il=graphics.length; i<il; i++) {
          graphic = graphics;
          if (extent.intersects(graphic.geometry)) {
   len = len + 1;
   var results = [];
  
   graphic.setSymbol(highlightSymbol);
   var featureAttributes = graphic.attributes;
   for (att in featureAttributes) {
             var s = featureAttributes[att];
    results.push(s);
   }
  
   attr = results.slice(0,10);
   for(var j=0, jl=10; j<jl; j++)
   {
    items.push(attr);
   }
  
    } //if
   
          else if (graphic.symbol == highlightSymbol) {
            graphic.setSymbol(symbol);
          }
   
        } //for
  map.setExtent(//some polygon feature//.geometry.getExtent());
}

[HemingZhu]

Hi,
I am running a query to select a number of polygons based on an intersecting polygon. The selected polygons are contiguous and are highlighted when the query is complete. I am trying to set the map extent to the extent of all these polygons combined together but have been unsuccessful. I have tried suggestions posted on these forums and using samples provided by ESRI but am still unable to get the map to zoom to this area. I have tried creating an array to push graphics inside it. I have also tried creating a polygon feature, a feature set and a graphicsLayer as a container to hold all the selected graphics, but it didn't work. I am using ArcGIS Server 9.3 with JavaScript API. Please help.
(Note: The code below has been extracted from a longer version. It might be missing some braces)

function findPolygonsInExtent(extent) {
      
  var graphics = map.graphics.graphics;     
  var attr =[];
  var items = [];
        var graphic;
  var len=0;
       
  for (var i=0, il=graphics.length; i<il; i++) {
          graphic = graphics;
          if (extent.intersects(graphic.geometry)) {
   len = len + 1;
   var results = [];
  
   graphic.setSymbol(highlightSymbol);
   var featureAttributes = graphic.attributes;
   for (att in featureAttributes) {
             var s = featureAttributes[att];
    results.push(s);
   }
  
   attr = results.slice(0,10);
   for(var j=0, jl=10; j<jl; j++)
   {
    items.push(attr);
   }
  
    } //if
   
          else if (graphic.symbol == highlightSymbol) {
            graphic.setSymbol(symbol);
          }
   
        } //for
  map.setExtent(//some polygon feature//.geometry.getExtent());
}

the utility function esri.graphicsExtent(graphics) returns the extent of graphics. It included in javascript api 1.6. So it should wok on ArcGIS server 9.3. If not, you just have to create a logic in you for loop for (var i=0, il=graphics.length; i<il; i++)  to calculate an extent that contains all your graphics. let me know if you need more help on how.

[SamirGambhir]

Thanks Heming,
I looked up ARcGIS resource Center but could not find any example to use esri.graphicsExtent function. I'll really appreciate it if you can guide me a bit more.
Thanks
Samir

[HemingZhu]

Thanks Heming,
I looked up ARcGIS resource Center but could not find any example to use esri.graphicsExtent function. I'll really appreciate it if you can guide me a bit more.
Thanks
Samir

Here is link: http://help.arcgis.com/en/webapi/javascript/arcgis/help/jsapi/namespace_esri.htm#esri.graphicsExtent . could use this method like this. var extent =esri.graphicsExtent(map.graphics.graphics)... map.setExtent(extent).

[SamirGambhir]

Thanks Heming,
I am not sure where to put his piece of code in my code. If you notice, I am selecting a subset of graphics from the overall set of graphics based on the intersecting criteria. I need to set the extent to the selected subset of graphics only.
Thanks again,
Samir

[HemingZhu]

Hi, 
I am running a query to select a number of polygons based on an intersecting polygon. The selected polygons are contiguous and are highlighted when the query is complete. I am trying to set the map extent to the extent of all these polygons combined together but have been unsuccessful. I have tried suggestions posted on these forums and using samples provided by ESRI but am still unable to get the map to zoom to this area. I have tried creating an array to push graphics inside it. I have also tried creating a polygon feature, a feature set and a graphicsLayer as a container to hold all the selected graphics, but it didn't work. I am using ArcGIS Server 9.3 with JavaScript API. Please help. 
(Note: The code below has been extracted from a longer version. It might be missing some braces) 

function findPolygonsInExtent(extent) { 
  
var graphics = map.graphics.graphics;  
var attr =[]; 
var items = []; 
var graphic; 
var len=0; 
   var intersectedGraphics =[];
  
for (var i=0, il=graphics.length; i<il; i++) { 
graphic = graphics; 
if (extent.intersects(graphic.geometry)) { 
   intersectedGraphics.push(graphic);
len = len + 1; 
var results = []; 
  
graphic.setSymbol(highlightSymbol);  
var featureAttributes = graphic.attributes; 
for (att in featureAttributes) { 
var s = featureAttributes[att]; 
results.push(s); 
} 
  
attr = results.slice(0,10); 
for(var j=0, jl=10; j<jl; j++) 
{ 
items.push(attr); 
} 
  
} //if 
  
else if (graphic.symbol == highlightSymbol) { 
graphic.setSymbol(symbol); 
} 
  
} //for 
   var extent =esri.graphicsExtent(intersectedGraphics);
map.setExtent(extent);
}

function findPolygonsInExtent(extent) {

var graphics = map.graphics.graphics;
var attr =[];
var items = [];
var graphic;
var len=0;
var intersectedGraphics =[];

for (var i=0, il=graphics.length; i<il; i++) {
graphic = graphics;
if (extent.intersects(graphic.geometry)) {
intersectedGraphics.push(graphic);
len = len + 1;
var results = [];

graphic.setSymbol(highlightSymbol);
var featureAttributes = graphic.attributes;
for (att in featureAttributes) {
var s = featureAttributes[att];
results.push(s);
}

attr = results.slice(0,10);
for(var j=0, jl=10; j<jl; j++)
{
items.push(attr);
}

} //if

else if (graphic.symbol == highlightSymbol) {
graphic.setSymbol(symbol);
}

} //for
var extent =esri.graphicsExtent(intersectedGraphics);
map.setExtent(extent);
}

[SamirGambhir]

Hi Heming,
This works great! Thanks for all your help.
Samir

[JasonMiller1]

I'm doing this same thing, using the same method.  It works for me some of the time.  I have a map that puts a route on there, similar to driving directions you'd get from Google maps and whatnot.  Sometimes, it zooms in perfectly.  Sometimes it zooms in too far, so it cuts the part of the route off.  Any idea what would cause this?

[HemingZhu]

I'm doing this same thing, using the same method.  It works for me some of the time.  I have a map that puts a route on there, similar to driving directions you'd get from Google maps and whatnot.  Sometimes, it zooms in perfectly.  Sometimes it zooms in too far, so it cuts the part of the route off.  Any idea what would cause this?

Use the map.setExtent(yourExtent, true) instead of map.setExtent(yourextent). It will garantee that your extent will fully show.

[JasonMiller1]

So simple, but that works like a champ.  Thanks for your help!