topic Re: Custom map center in ArcGIS JavaScript Maps SDK Questions

Custom map center

EvelynHernandez — Fri, 02 Mar 2018 14:04:23 GMT

Hello.

I want to know if there is a way to move the center of the map when querying a little bit.

Iam querying some feature (just 1 result) and im doing this for showing it in the center of the map.

map.centerAndZoom(featureSet.features[0].geometry.getExtent().getCenter(),20);

In my app when i do this i have a problem on visualization, thats why i want to move it to the right a little bit.

This is what i obtain: (See the blue line on the screen)

The red container is over the map, thats why when i do the center i got that.

this is what i want to get:

Thanks in advice

Re: Custom map center

RobertScheitlin__GISP — Fri, 02 Mar 2018 14:08:17 GMT

Evelyn,

Have you considered extent offset?

https://developers.arcgis.com/javascript/3/jsapi/extent-amd.html#offset

Re: Custom map center

EvelynHernandez — Fri, 02 Mar 2018 14:13:17 GMT

Oh no, is there any example on how to apply that?. I should do it into the map or how?

Thanks in advice

Re: Custom map center

RobertScheitlin__GISP — Sat, 11 Dec 2021 21:27:38 GMT

Evelyn,

So thing like this after your query is done and you get the extent you want to zoom to.

//your get the extent of your feature to zoom to and before
//you set the maps extent ofsset it by a certain Y
map.setExtent(extent.offset(200,0), true);‍‍‍

Re: Custom map center

EvelynHernandez — Sat, 11 Dec 2021 21:27:41 GMT

This work for me, thanks!

map.centerAndZoom(featureSet.features[0].geometry.getExtent().getCenter(),20);
map.setExtent(featureSet.features[0].geometry.getExtent().offset(-10,0), true);‍‍

Re: Custom map center

RobertScheitlin__GISP — Fri, 02 Mar 2018 15:19:54 GMT

Great, Don't forget to mark this question as answered by clicking on the "Mark Correct" link on the reply that answered your question.

Re: Custom map center

HoriaTudosie — Fri, 02 Mar 2018 19:28:59 GMT

I wonder if you cannot do it in just one step:

map.centerAndZoom(featureSet.features[0].geometry.getExtent().offset(10,0).getCenter(),20);

Re: Custom map center

EvelynHernandez — Sat, 11 Dec 2021 21:27:44 GMT

Hello again.

Im having an issue with this

map.centerAndZoom(featureSet.features[0].geometry.getExtent().offset(10,0).getCenter(),20);

The error says Cannot read property 'offset' of null.

Im doing a query to a layer and i got the geometry and attributes correctly.

So still i cannot move the extent to the position i want.

Re: Custom map center

HoriaTudosie — Tue, 13 Mar 2018 09:46:44 GMT

I do not have an environment at this moment to check the error.

Beside may be the fault of a corrupted layer.

I would put a breakpoint on that line to check if getExtent really returns something.

Sometimes, the layer may be corrupted and one or more features may have no geometry!

The error may come from those incomplete features without geometry.

Another ways to go around would be to extract the geometry and check it for null.

Then getExtent should return something, but you may check it again for null.

If you got a null for the two above checks, log the feature.

Or put in in a try/catch block and log the error along with the feature Id (or just the feature.)

This (either) way, you may find if that was the case (some features do not have geometries, although they should!

If so, keep (or add) the try/catch block with or without the log.

Re: Custom map center

EvelynHernandez — Tue, 13 Mar 2018 12:24:58 GMT

There is a geometry, but the function doesnt

Re: Custom map center

RobertScheitlin__GISP — Tue, 13 Mar 2018 15:03:02 GMT

Evelyn,

featureSet.features[0].geometry

Is a line or a polygon right? If it is a point then a point does not have an extent.

Re: Custom map center

EvelynHernandez — Tue, 13 Mar 2018 15:05:49 GMT

A point, thats why.

So how should i do the offset with a point?

Thanks in advice

Re: Custom map center

RobertScheitlin__GISP — Tue, 13 Mar 2018 15:17:10 GMT

Evelyn,

The Point Class in the JS API has an offset method as well.

https://developers.arcgis.com/javascript/3/jsapi/point-amd.html#offset

So your code would look like this instead:

map.centerAndZoom(featureSet.features[0].geometry.offset(10,0), 20);‍

Re: Custom map center

HoriaTudosie — Tue, 13 Mar 2018 17:26:27 GMT

Check the geometry type for the feature.

When is Point, get the current extent of the map and offset that instead!

(I think you should considering that for whatever geometry, but is up to you to consider it.)