Question

How do I set gmaps4rails to show Terrain view directly or by default for the whole application?

Answer 1

The defaults used for the map are these:

container_id:        "map_container",
id:               "map",
type:             "ROADMAP",   // HYBRID, ROADMAP, SATELLITE, TERRAIN
center_latitude : 0,
center_longitude: 0,
disableDefaultUI: false,
disableDoubleClickZoom: false,    
draggable: true,
mapTypeControl:  null,        // display the map type dropdown, unless set to false it will be displayed
detect_location: false,        // should the browser attempt to use geolocation detection features of HTML5?
center_on_user: false,         // centers map on the location detected through the browser
zoom :            1,           // initial zoom
maxZoom:       null,           //max zoom level
minZoom:       null,           //min zoom level   
auto_adjust:   true,           //adjust the map to the markers if set to true
auto_zoom:     true            //comes with auto_adjust. Choose whether or not you want to use an automatic zoom or the one you set in the 'zoom' option.
bounds:  []                    //adjust map to these limits. Should be [{"lat": , "lng": }, {"lat": , "lng": } ...]

I am not sure how to override the default for the whole application, but you canchange from ROADMAP to TERRAIN in the views:

<%= gmaps({"map_options" => { type => "TERRAIN" })%>