i am doing the tutorial for displaying the map in a web browser
https://developers.arcgis.com/javascript/3/jshelp/intro_agstemplate_amd.html
now I have the code, what if I don't want to display all the layers, and want to turn off the first layer?
i can do it by index of the layer, or can i use the layer name?
trying to understand i got to https://developers.arcgis.com/javascript/3/jsapi/arcgisdynamicmapservicelayer-amd.html but not sure how to use javascript
thanks guys.
If you want to turn off and on layers manually, I would use the layerlist widget script LayerList widget
or if you need the option to reorder the layers with the ability to turn layers on or off manually I would use the Reorder layers in map service
Related
I need to filter features by one specific attribute which is same for every layer that I am using. I tried this tutorial https://developers.arcgis.com/javascript/latest/sample-code/featurefilter-attributes/ which workrs fine but just for one layer. How can I modify this code to add another layers?
I want to filter on client side. My code is the same as in tutorial
You will need to apply the filter to each layer view, there is no general filter on the map.
I should not be much effort though, just iterate over the layers on the map, an in case of FeatureLayer apply filter to the FeatureLayerView.
ArcGIS API JS - Map
I'm developing a small app using Google Maps javascript API v3 where I need to display 2 markers and update their positions using ajax. I found no problem in doing it using Google Maps Markers, but I need a more customized marker so I'm using Google Maps custom overlays and I can't find the way to make the movements smooth.
This is the design of the markers (that also uses css animations, so I need custom html):
Markers design
The problem I have is that I can't find a way to actually move the custom overlay on the map. What I'm doing now is removing the overlay and creating a new one every time I have to move it, what makes a little blink and don't allow me to make a smooth transition from one position to the other.
So here are my questions:
1- Is using custom overlays the best way to build the markers according to the design? Is there any way to make Google Maps Markers look like the design?
2- If using custom overlays (https://developers.google.com/maps/documentation/javascript/customoverlays) is the best option, is there another way for moving them that is not removing and creating a new one?
Thanks in advance!
After struggling with this some time (it really took me several hours) I have manage to do it getting inspired by this fiddle:
https://jsfiddle.net/doktormolle/QRuW8/
The functionality is not the same, but I could get some ideas.
Since there is not a lot of documentation I have created my own fiddle with a working (and simplified) example, just in case is useful for anyone:
https://jsfiddle.net/javigbas/3zx5xa2u/
:)
I have a map of points, and for each of those points, a specific extent that I want the map to zoom into when I click on it.
I assume I will need to tabulate the bounds of those extents and add them as another column in the data.
Is there a way for Carto to automatically zoom to the bounds once I do this?
Yes you need to develop a CARTO.js web application. You need of course to store the bounds somehow on your table in a set of columns or in one single column using a format you can later parse. Next, you need to add that/those fields to a custom infowindow so they are passed to the web application in the interactivity. Finally, you need to listen to the feature click event in order to retrieve the interactivity data and using Leaflet map methods move its bounds.
You have all CARTO.js documentation here and a tutorial and many examples here. It's easier than it seems.
I want to control which types of roads show from this OSM highways list at various zoom levels.
I could not find the answer in the Leaflet docs. If you do, please link me.
edit:
Maybe i need to go one step back in the making stack and use one of these frameworks? http://wiki.openstreetmap.org/wiki/Frameworks#Generating_map_images
It is not possible to alter displayed map style in Leaflet.
Probably the fastest way to achieve your goal is:
Create your map style in Mabox Studio, where you will specify the road types to be displayed at various zoom levels. Mapbox will render the map tiles for you and expose them via URL.
then display the tiles created in Mapbox Studio in Leaflet (or Mapbox.js which is build above leaflet) simply by altering the map tiles URL you use when you initialize leaflet.
I'm somehow new in making web services using Openlayers and Javascript. I would like to create a clickable grid layer on top of a map (e.g. OSM) which first has a defined spatial resolution (e.g. 200 m) and of course when user zooms the grid size adapts to the new zoom level of the map. Also I want to show every cell of a grid with a specific colour, and when the user clicks on each cell some information can be shown. So, I guess each cell is like a feature in this layer (e.g. polygon). I was wondering if Openlayers has existing function to do such a thing that I can use, or do I have to code all of it? any help and suggestions on how I can manage to do this would be highly appreciated. Below is a link to a service that has created such a service, I would like to do the same... Thanx.
Link to sample:
http://koenigstuhl.geog.uni-heidelberg.de/osmatrix/#timestamp/allotments_area/8/12/-0.2142333984375/51.578776399817066
Having developed the application you mention in your example, I can give you some hints on your question. The solution is pretty straightforward.
The grid you see, i.e. the coloured hexagons, is simply map tiles, that are served by a custom back-end following the Tile Map Service schema (I used NodeJS) that, in turn, uses Mapnik (any other engine should work as well, e.g. GeoServer or MapServer) for rendering the images. The data is stored in a Postgres data base with PostGIS added on.
Use a client-side library to create the map and add the tiled layer. OpenLayers and Leaflet both do the job well. (Leaflet, though, is a bit easier to grasp if your new to the topic).
On client side you register a click-event handler on the Map, that you can use to get the coordinates of the mouse click. Use these coordinates, send them to your back-end and perform a spatial query on the data base to get the polygons adjacent to the coordinates. The server's response should then provide the geometries of the polygons (encoded in GeoJSON in this case, GML, KML should work fine as well) and whatever information you want to display.
Use these polygons and add them to a vector layer using whatever colour scheme you want.
Have a look at the code to see how it works. The important files are osmatrix.js (connects to the back-end), control.js (main module, keeps track of everything) and map.js (surprisingly enough, everything map-related).
Openlayers has facilities for creating an interactive vector later. In order to create something like in the example, you would have to 1) add a vector layer, 2) write a loop that adds vector features to the appropriate locations on the map, 3) style the features as hexagons, and 4) create a stylemap that dynamically sets the feature color based on the appropriate parameters. Each step is facilitated by Openlayers.
A good start is to use the leaflet library because it use the map projection and to read this tutorial: http://build-failed.blogspot.de/2013/07/dynamically-creating-hexagons-from-real.html?m=1.