Maps in JavaScript

js.arcgis.com

esri/Map Class

contains properties and methods for storing, managing, and overlaying layers common to both 2D and 3D viewing.

A single map may be referenced by multiple views

Views

A MapView displays a 2D view of a Map instance. An instance of MapView must be created to render a Map in 2D.

A SceneView displays a 3D view of a Map instance.

https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=intro-mapview

https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=scene-environment

https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=views-synchronize

Layers

• the most fundamental component of a Map
• a collection of spatial data in the form of vector graphics or raster images that represent real-world phenomena.
• may contain discrete features that store vector data or continuous cells/pixels that store raster data.
• Multiple layers may be added to the same map and overlaid on top of one another for visualization and analytical purposes

Which to Use?

• GraphicsLayer (client-side layer)
  • Dynamic data from other part (JS or back-end) of application.
  • Examples:
    • Place a point on the map where the user's registered location is
    • Allow the user to click on the map and you want to place a pin at that location
  • Demo (associated guide)

Which to Use?

• FeatureLayer
  • Similar in representation to the GraphicsLayer, but data displayed comes from an ArcGIS REST API (FeatureService URL)
  • Examples:
    • Show building footprints (polygons) of a campus
    • Show voting districts and allow visitor to highlight which districts voted in a specific way
    • You have a dataset you want to host in ArcGIS Online and then display it (Guide)
  • Demo
  • Query Demo
  • Create a Hosted FeatureService from scratch demo

Which to Use?

• MapImageLayer
  • allows you to display and analyze data from sublayers defined in a map service, exporting images instead of features
  • MapImageLayer processing is handled by the server, not the client.
  • Examples:
    • Displaying reference layers on your map, like crime data from ArcGIS Living Atlas.
      • If you find any ArcGIS REST Endpoint online that ends with "/mapserver/" in general you can add that to your map using this layer type.
  • Demo - Modify rendering of MapImageLayer on the Fly
  •  

• Build your map in ArcGIS Online, then create that map by ID.
• Demo

esriurl.com/hackgt18js

Slack: #esri

Bonus: Geolocation