Multilayer is achieved through an angularjs-based selector (to keep HTML as clean and self-contained as possible) and a basemap-agnostic (i.e. it works with Leaflet, Google maps or whatever) logic.

One layer per visualization and one visualization per layer.

Example URL:

http://multilayer.cartodb.io/multilayer.html?u=dcarrion&t=multilayer&v=9c5ed27c-ad4f-11e4-ae79-0e853d047bba&tt=Multilayer%20map&d=Description%20test

URL params:

• u: username
• t: table with the layers
• v: viz.json UUID for the basemap (this visualization may contain data as well, but please remember this layer is not included in the selector and can't be hidden)
• tt: Title of the map
• d: Description - Keep it short!

Required row fields in the layer table:

• cartodb_id: not used
• the_geom: not_used
• name: name to appear in the selector
• show: true if layer is to be displayed initially
• viz_json: URL for the viz.json that corresponds to the visualization (takes precedence over sql and cartocss)
• sql: SQL query for the data in the layer (used if viz_json is not present)
• sql_user: user name for the SQL query (used if viz_json is not present)
• cartocss: CartoCSS for the layer (used if viz_json is not present)
• interactivity: Fields to interact with for the layer (used if viz_json is not present)
• created_at: not used
• modified_at: not used