MapView API

Provides an embeddable map interface. See GeoLocation/controller.rb of System API sample application for some examples of using the MapView class.

There are several settings you should know when you use the MapView API, such as setting . Refer to the MapView settings in Device Capabilities.

• Using JavaScript API
• create
• set_file_caching_enable
• preload_map_tiles

Using JavaScript API

You can call the MapView methods from JavaScript as well as Ruby. To use the JavaScript API, add the public/js/rho_javascript_api.js file – created at build time as part of the application package – to the .html, .erb, or .js file calling the JavaScript method.

The JavaScript API methods with a return value can pass it as a parameter in jQuery-compatible continuation (deferred object, a kind of callback). Possible continuations to handle are done, fail, and complete.

Rho.Class.method(params).done(function(handler) { /* handler... */ })

You must enable JavaScript by putting rho-javascript into extensions in your build.yml.

extensions: ["rho-javascript"]

You must have a RhoElements license to use the JavaScript API.

create

Create a map on your device. Click here for an example of MapView create.

Ruby syntax:

MapView.create map_params

JavaScript syntax:

Rho.MapView.create(map_params)

map_params hash

Click here for an example of MapView create, which sets the map_params hash.

map_params is a hash consisting of:

To use ESRI maps in your projects on iPhone:

• Install ESRI iOS SDK - use default folders during installations !
• Add “esri” to your applications extensions list in build.yml file.

annotations array (in map_params hash)

The annotations parameter within the map_params hash is an array. Click here for an example of MapView create, which sets this array.

The annotations array has the following format.

settings hash (in map_params hash)

The settings parameter within the map_params hash is also a hash. Click here for an example of MapView create, which sets this hash.

The settings hash has the following format.

region (in settings hash)

In the settings hash (settings ia a parameter within the map_params hash), the region can be of two types: [latitude,longitude,latitudeDelta,longitudeDelta] or {:center => center, :radius => radius}.

region type [latitude,longitude,latitudeDelta,longitudeDelta]

Click here for an example of MapView create, which sets this region type.

region type {:center => center, :radius => radius}

set_file_caching_enable

Enable file caching for map tiles. The file cache can be used for offline map browsing.

Caching saves map tiles to your device. It increases performance of map view: when the device user scrolls map view to an already viewed map area, the device does not have to reload the map tiles. Tiles take up memory, so the developer should decide when to use caching.

Ruby syntax:

MapView.set_file_caching_enable(enable)

JavaScript syntax:

Rho.MapView.set_file_caching_enable(enable)

preload_map_tiles

Preload a map tiles for a region defined by a zoom level range (0<=zoom<=18). This function requires some understanding about map engine funtionality, such as map tiles.

Click here for an example of MapView preload_map_tiles.

When the map view is opened after preload_map_tiles is called, the preloaded area can display more quickly because the only map tiles displayed are in the defined zoom range.

Ruby syntax:

MapView.preload_map_tiles(options_hash, url_for(:action => :preload_callback))

JavaScript Syntax:

Rho.MapView.preload_map_tiles(options_hash, callback)

Returns the total number of tiles for this preload. You can use this total to calculate the required space, predict the required time, etc.

options_hash

options_hash is a hash containing the following parameters for preload_map_tiles.

preload_callback

The preloading process can take a long time. Write the preload_callback method to get periodic information about the process, using the parameters “status” and “progress”.