Feature Collection¶
| Category | Requires | Version |
|---|---|---|
| Maps | API 21, Android 5.0 Lollipop | 2 |
Overview¶
A FeatureColletion contains one or more map features as a group. Any events fired on a feature in the collection will also trigger the corresponding event on the collection object. FeatureCollections can be loaded from external resources as a means of populating a Map with content.
Events¶
Feature Click¶
The user clicked on a map feature.
| Params | |
|---|---|
| feature | Component |
Feature Drag¶
The user dragged a map feature.
| Params | |
|---|---|
| feature | Component |
Feature Long Click¶
The user long-pressed on a map feature.
| Params | |
|---|---|
| feature | Component |
Feature Start Drag¶
The user started dragging a map feature.
| Params | |
|---|---|
| feature | Component |
Feature Stop Drag¶
The user stopped dragging a map feature.
| Params | |
|---|---|
| feature | Component |
Got Features¶
A GeoJSON document was successfully read from url. The features specified in the document are provided as a list in features.
| Params | |
|---|---|
| url | Text |
| features | List |
Load Error¶
An error was encountered while processing a GeoJSON document at the given url. The responseCode parameter will contain an HTTP status code and the errorMessage parameter will contain a detailed error message.
| Params | |
|---|---|
| url | Text |
| response Code | Number |
| error Message | Text |
Methods¶
Feature From Description¶
Returns: Any
Convert a feature description into an App Inventor map feature. Currently the onlysupported conversion is from a GeoJSON point to Marker component. If the feature hasproperties, they will be mapped into App Inventor properties using the following mapping:description becomes Description;draggable becomes Draggable;infobox becomes EnableInfobox;fill becomes FillColor;fill-opacity becomes FillOpacity;image becomes ImageAsset;stroke becomes StrokeColor;stroke-opacity becomes StrokeOpacity;stroke-width becomes StrokeWidth;title becomes Title;visible becomes Visible
| Params | |
|---|---|
| description | List |
Load From URL¶
Load a feature collection in GeoJSON format from the given url. On success, the event GotFeatures will be raised with the given url and a list of the features parsed from the GeoJSON as a list of (key, value) pairs. On failure, the LoadError event will be raised with any applicable HTTP response code and error message.
| Params | |
|---|---|
| url | Text |
Properties¶
Features¶
List 
Read Write - Blocks
The list of features placed on this map. This list also includes any features created by calls to FeatureFromDescription
Features From Geo JSON¶
Text Write - Designer Blocks
Loads a collection of features from the given string. If the string is not valid GeoJSON, the ErrorLoadingFeatureCollection error will be run with url =
Height¶
Number Read Write - Blocks
Specifies the component's vertical height, measured in pixels.
Height Percent¶
Number Write - Blocks
Specifies the component's vertical height as a percentageof the height of its parent Component.
Source¶
Text Read - Designer Blocks
Gets or sets the source URL used to populate the feature collection. If the feature collection was not loaded from a URL, this will be the empty string.
Visible¶
Boolean Default: True Read Write - Designer Blocks
Returns true iff the component is visible.
Width¶
Number Read Write - Blocks
Specifies the component's horizontal width, measured in pixels.
Width Percent¶
Number Write - Blocks
Specifies the component's horizontal width as a percentageof the Width of its parent Component.