Map View
- class tethys_sdk.gizmos.MapView(height='100%', width='100%', basemap=None, view=None, controls=None, layers=None, draw=None, legend=False, attributes=None, classes='', disable_basemap=False, feature_selection=None, show_clicks=False)
The Map View gizmo can be used to produce interactive maps of spatial data. It is powered by OpenLayers, a free and open source pure javascript mapping library. It supports layers in a variety of different formats including WMS, Tiled WMS, GeoJSON, KML, and ArcGIS REST. It includes drawing capabilities and the ability to create a legend for the layers included in the map.
Shapes that are drawn on the map by users can be retrieved from the map via a hidden text field named 'geometry' and it is updated every time the map is changed. The text in the text field is a string representation of JSON. The geometry definition contained in this JSON can be formatted as either GeoJSON or Well Known Text. This can be configured via the output_format option of the MVDraw object. If the Map View is embedded in a form, the geometry that is drawn on the map will automatically be submitted with the rest of the form via the hidden text field.
- height
Height of the map element. Any valid css unit of length (e.g.: '500px'). Defaults to '520px'.
- Type:
str
- width
Width of the map element. Any valid css unit of length (e.g.: '100%'). Defaults to '100%'.
- Type:
str
- attributes
A dictionary representing additional HTML attributes to add to the primary element (e.g. {"onclick": "run_me();"}).
- Type:
dict
- classes
Additional classes to add to the primary HTML element (e.g. "example-class another-class").
- Type:
str
- basemap
The base maps to display: choose from OpenStreetMap, MapQuest, or a Bing map. Valid values for the string option are: 'OpenStreetMap' and 'MapQuest'. If you wish to configure the base map with options, you must use the dictionary form. The dictionary form is required to use a Bing map, because an API key must be passed as an option. See below for more detail. A basemap switcher will automatically be provided if a list of more than one basemap is included.
- Type:
str, dict or a list of strings and/or dicts
- controls
A list of controls to add to the map. The list can be a list of strings or a list of dictionaries. Valid controls are ZoomSlider, Rotate, FullScreen, ScaleLine, ZoomToExtent, and 'MousePosition'. See below for more detail.
- Type:
list
- show_clicks
Show a point on the map where the user clicks if True. Defaults to False. Use the TETHYS_MAP_VIEW.mapClicked() JavaScript API endpoint to provide a callback that will be called each time the map is clicked on. Use the TETHYS_MAP_VIEW.clearClickedPoint() to remove the clicked point.
- Type:
bool
Options Dictionaries
Many of the options above will accept dictionaries with additional options. These dictionaries should be structured with a single key that is the name of the original option with a value of another dictionary containing the additional options. For example, to provide additional options for the 'ZoomToExtent' control, you would create a dictionary with key 'ZoomToExtent' and value of a dictionary with the additional options like this:
{'ZoomToExtent': {'projection': 'EPSG:4326', 'extent': [-135, 22, -55, 54]}}Most of the additional options correspond with the options objects in the OpenLayers API. The following sections provide links to the OpenLayers objects that you can refer to when selecting the options.
Base Maps
There are several base maps supported by the Map View gizmo: OpenStreetMap, Bing, Azure, CartoDB, and ESRI. All base maps can be specified as a string or as an options dictionary. When using an options dictionary all base maps map services accept the option control_label, which is used to specify the label to be used in the Base Map control. For example:
{'Bing': {'key': 'Ap|k3yheRE', 'imagerySet': 'Aerial', 'control_label': 'Bing Aerial'}} {'Azure': {'tilesetId': 'microsoft.imagery', 'subscriptionKey': 'Ap|k3yheRE', 'layer': 'Imagery'}}Note
The Bing Map service has been depricated in favor of Azure Maps service. For more options for Azure Maps tilesetId, please refer to this link: TilesetID
For additional options that can be provided to each base map service see the following links:
OpenStreetMap: ol/source/OSM
Bing: ol/source/BingMaps
XYZ ol/source/XYZ
Note
The CartoDB and ESRI services are just pre-defined instances of the XYZ service. In addition to the standard XYZ options they have the following additional options:
- CartoDB:
style: The style of map. Possibilities are 'light' or 'dark'.
labels: Boolean specifying whether or not to include labels.
- ESRI:
- layer: A string specifying which ESRI map to use. Possibilities are:
NatGeo_World_Map
Ocean_Basemap
USA_Topo_Maps
World_Imagery
World_Physical_Map
World_Shaded_Relief
World_Street_Map
World_Terrain_Base
World_Topo_Map
Controls
Use the following links to learn about options for the different controls:
FullScreen: ol.control.FullScreen
MousePosition: ol.control.MousePosition
Rotate: ol.control.Rotate
ScaleLine: ol.control.ScaleLine
ZoomSlider: ol.control.ZoomSlider
ZoomToExtent: ol.control.ZoomToExtent
Feature Selection
The feature_selection dictionary contains global settings that can be used to modify the behavior of the feature selection functionality. An explanation of valid options follows:
multiselect: Set to True to allow multiple features to be selected while holding the shift key on the keyboard. Defaults to False.
sensitivity: Integer value that adjust the feature selection sensitivity. Defaults to 2.
Tip
OpenLayers Version
Currently, OpenLayers version 5.3.0 is used by default with the Map View gizmo. If you need a specific version of OpenLayers you can specify the version number using the ol_version class attribute on the MapView class:
MapView.ol_version = '4.6.5'Any versions that are provided by https://www.jsdelivr.com/package/npm/openlayers can be specified.
Controller Example
from tethys_sdk.gizmos import MapView, MVDraw, MVView, MVLayer, MVLegendClass # Define view options view_options = MVView( projection='EPSG:4326', center=[-100, 40], zoom=3.5, maxZoom=18, minZoom=2 ) # Define drawing options drawing_options = MVDraw( controls=['Modify', 'Delete', 'Move', 'Point', 'LineString', 'Polygon', 'Box'], initial='Point', output_format='WKT' ) # Define GeoJSON layer geojson_object = { 'type': 'FeatureCollection', 'crs': { 'type': 'name', 'properties': { 'name': 'EPSG:3857' } }, 'features': [ { 'type': 'Feature', 'geometry': { 'type': 'Point', 'coordinates': [0, 0] } }, { 'type': 'Feature', 'geometry': { 'type': 'LineString', 'coordinates': [[4e6, -2e6], [8e6, 2e6]] } }, { 'type': 'Feature', 'geometry': { 'type': 'Polygon', 'coordinates': [[[-5e6, -1e6], [-4e6, 1e6], [-3e6, -1e6]]] } } ] } # Define GeoJSON point layer geojson_point_object = { 'type': 'FeatureCollection', 'crs': { 'type': 'name', 'properties': { 'name': 'EPSG:3857' } }, 'features': [ { 'type': 'Feature', 'geometry': { 'type': 'Point', 'coordinates': [0, 0] } }, ] } style = {'ol.style.Style': { 'stroke': {'ol.style.Stroke': { 'color': 'blue', 'width': 2 }}, 'fill': {'ol.style.Fill': { 'color': 'green' }}, 'image': {'ol.style.Circle': { 'radius': 10, 'fill': None, 'stroke': {'ol.style.Stroke': { 'color': 'red', 'width': 2 }} }} }} geojson_layer = MVLayer( source='GeoJSON', options=geojson_object, layer_options={'style': style}, legend_title='Test GeoJSON', legend_extent=[-46.7, -48.5, 74, 59], legend_classes=[ MVLegendClass('polygon', 'Polygons', fill='green', stroke='blue'), MVLegendClass('line', 'Lines', stroke='blue') ] ) geojson_point_layer = MVLayer( source='GeoJSON', options=geojson_point_object, legend_title='Test GeoJSON', legend_extent=[-46.7, -48.5, 74, 59], legend_classes=[ MVLegendClass('line', 'Lines', stroke='#3d9dcd') ], ) # Define GeoServer Layer geoserver_layer = MVLayer( source='ImageWMS', options={'url': 'http://192.168.59.103:8181/geoserver/wms', 'params': {'LAYERS': 'topp:states'}, 'serverType': 'geoserver'}, legend_title='USA Population', legend_extent=[-126, 24.5, -66.2, 49], legend_classes=[ MVLegendClass('polygon', 'Low Density', fill='#00ff00', stroke='#000000'), MVLegendClass('polygon', 'Medium Density', fill='#ff0000', stroke='#000000'), MVLegendClass('polygon', 'High Density', fill='#0000ff', stroke='#000000') ] ) # Define KML Layer kml_layer = MVLayer( source='KML', options={'url': '/static/tethys_gizmos/data/model.kml'}, legend_title='Park City Watershed', legend_extent=[-111.60, 40.57, -111.43, 40.70], legend_classes=[ MVLegendClass('polygon', 'Watershed Boundary', fill='#ff8000'), MVLegendClass('line', 'Stream Network', stroke='#0000ff'), ] ) # Tiled ArcGIS REST Layer arc_gis_layer = MVLayer( source='TileArcGISRest', options={'url': 'http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/' + 'Specialty/ESRI_StateCityHighway_USA/MapServer'}, legend_title='ESRI USA Highway', legend_extent=[-173, 17, -65, 72] ) # Define base map options esri_layer_names = [ 'NatGeo_World_Map', 'Ocean_Basemap', 'USA_Topo_Maps', 'World_Imagery', 'World_Physical_Map', 'World_Shaded_Relief', 'World_Street_Map', 'World_Terrain_Base', 'World_Topo_Map', ] esri_layers = [{'ESRI': {'layer': l}} for l in esri_layer_names] azure_layers = [ {'Azure': {'tilesetId': 'microsoft.imagery', 'subscriptionKey': 'Ap|k3yheRE', 'layer': 'Imagery'}}, [ {'Azure': {'tilesetId': 'microsoft.imagery', 'subscriptionKey': 'Ap|k3yheRE', 'layer': 'Imagery'}}, {'Azure': {'tilesetId': 'microsoft.base.labels.road', 'subscriptionKey': 'Ap|k3yheRE', 'layer': 'Label'}} ], {'Azure': {'tilesetId': 'microsoft.base.road', 'subscriptionKey': 'Ap|k3yheRE', 'layer': 'Road'}} ] basemaps = [ 'OpenStreetMap', 'CartoDB', {'CartoDB': {'style': 'dark'}}, {'CartoDB': {'style': 'light', 'labels': False, 'control_label': 'CartoDB-light-no-labels'}}, {'XYZ': {'url': 'https://maps.wikimedia.org/osm-intl/{z}/{x}/{y}.png', 'control_label': 'Wikimedia'}}, 'ESRI', ] basemaps.extend([esri_layers, azure_layers]) # Specify OpenLayers version MapView.ol_version = '5.3.0' # Define map view options map_view_options = MapView( height='600px', width='100%', controls=['ZoomSlider', 'Rotate', 'FullScreen', {'MousePosition': {'projection': 'EPSG:4326'}}, {'ZoomToExtent': {'projection': 'EPSG:4326', 'extent': [-130, 22, -65, 54]}}], layers=[geojson_layer, geojson_point_layer, geoserver_layer, kml_layer, arc_gis_layer], view=view_options, basemap=basemaps, draw=drawing_options, legend=True ) context = {'map_view_options': map_view_options}Template Example
{% load tethys %} {% gizmo map_view_options %}
MVLayer
- class tethys_sdk.gizmos.MVLayer(source, options, legend_title, layer_options=None, editable=True, legend_classes=None, legend_extent=None, legend_extent_projection='EPSG:4326', feature_selection=None, geometry_attribute=None, data=None, times=None)
MVLayer objects are used to define map layers for the Map View Gizmo.
- options
A dictionary representation of the OpenLayers options object for ol.source.
- Type:
dict, required
- legend_title
The human readable name of the layer that will be displayed in the legend.
- Type:
str, required
- editable
If true the layer will be editable with the tethys_map_view drawing/editing tools.
- Type:
bool
- legend_extent
A list of four ordinates representing the extent that will be used on "zoom to layer": [minx, miny, maxx, maxy].
- Type:
list
- legend_extent_projection
The EPSG projection of the extent coordinates. Defaults to "EPSG:4326".
- Type:
str
- times
List of time steps if layer is time-enabled. Times should be represented as strings in ISO 8601 format (e.g.: ["20210322T112511Z", "20210322T122511Z", "20210322T132511Z"]). Currently only supported in CesiumMapView.
- Type:
list
Example
# Define GeoJSON layer geojson_object = { 'type': 'FeatureCollection', 'crs': { 'type': 'name', 'properties': { 'name': 'EPSG:3857' } }, 'features': [ { 'type': 'Feature', 'geometry': { 'type': 'Point', 'coordinates': [0, 0] } }, { 'type': 'Feature', 'geometry': { 'type': 'LineString', 'coordinates': [[4e6, -2e6], [8e6, 2e6]] } }, { 'type': 'Feature', 'geometry': { 'type': 'Polygon', 'coordinates': [[[-5e6, -1e6], [-4e6, 1e6], [-3e6, -1e6]]] } } ] } style_map = { 'Point': {'ol.style.Style': { 'image': {'ol.style.Circle': { 'radius': 5, 'fill': {'ol.style.Fill': { 'color': 'red', }}, 'stroke': {'ol.style.Stroke': { 'color': 'red', 'width': 2 }} }} }}, 'LineString': {'ol.style.Style': { 'stroke': {'ol.style.Stroke': { 'color': 'green', 'width': 3 }} }}, 'Polygon': {'ol.style.Style': { 'stroke': {'ol.style.Stroke': { 'color': 'blue', 'width': 1 }}, 'fill': {'ol.style.Fill': { 'color': 'rgba(0, 0, 255, 0.1)' }} }}, } geojson_layer = MVLayer(source='GeoJSON', options=geojson_object, layer_options={'style_map': style_map}, legend_title='Test GeoJSON', legend_extent=[-46.7, -48.5, 74, 59], legend_classes=[ MVLegendClass('polygon', 'Polygons', fill='rgba(0, 0, 255, 0.1)', stroke='blue'), MVLegendClass('line', 'Lines', stroke='green'), MVLegendClass('point', 'Points', fill='red') ]) # Define GeoServer Layer geoserver_layer = MVLayer(source='ImageWMS', options={'url': 'http://192.168.59.103:8181/geoserver/wms', 'params': {'LAYERS': 'topp:states'}, 'serverType': 'geoserver'}, legend_title='USA Population', legend_extent=[-126, 24.5, -66.2, 49], legend_classes=[ MVLegendClass('polygon', 'Low Density', fill='#00ff00', stroke='#000000'), MVLegendClass('polygon', 'Medium Density', fill='#ff0000', stroke='#000000'), MVLegendClass('polygon', 'High Density', fill='#0000ff', stroke='#000000') ]) # Define GeoServer Tile Layer with Custom tile grid # The default EPSG:900913 gridset can be used with OpenLayers. # You must ensure that OpenLayers requests tiles with the same gridset and origin as the gridset GeoServer uses # to use GeoWebCaching capabilities. This is done by setting the TILESORIGIN parameter and specifying a custom tileGrid. # Refer to OpenLayers API for ol.tilegrid.TileGrid for explanation and options. # See: http://docs.geoserver.org/2.7.0/user/webadmin/tilecache/index.html geoserver_layer = MVLayer(source='TileWMS', options={'url': 'http://192.168.59.103:8181/geoserver/wms', 'params': {'LAYERS': 'topp:states', 'TILED': True, 'TILESORIGIN': '0.0,0.0'}, 'serverType': 'geoserver', 'tileGrid': { 'resolutions': [ 156543.03390625, 78271.516953125, 39135.7584765625, 19567.87923828125, 9783.939619140625, 4891.9698095703125, 2445.9849047851562, 1222.9924523925781, 611.4962261962891, 305.74811309814453, 152.87405654907226, 76.43702827453613, 38.218514137268066, 19.109257068634033, 9.554628534317017, 4.777314267158508, 2.388657133579254, 1.194328566789627, 0.5971642833948135, 0.2985821416974068, 0.1492910708487034, 0.0746455354243517, ], 'extent': [-20037508.34, -20037508.34, 20037508.34, 20037508.34], 'origin': [0, 0], 'tileSize': [256, 256] } }, legend_title='USA Population') # Define KML Layer kml_layer = MVLayer(source='KML', options={'url': '/static/tethys_gizmos/data/model.kml'}, legend_title='Park City Watershed', legend_extent=[-111.60, 40.57, -111.43, 40.70], legend_classes=[ MVLegendClass('polygon', 'Watershed Boundary', fill='#ff8000'), MVLegendClass('line', 'Stream Network', stroke='#0000ff'), ]) # Tiled ArcGIS REST Layer arc_gis_layer = MVLayer(source='TileArcGISRest', options={'url': 'http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/' + 'Specialty/ESRI_StateCityHighway_USA/MapServer'}, legend_title='ESRI USA Highway', legend_extent=[-173, 17, -65, 72]),
MVLegendClass
- class tethys_sdk.gizmos.MVLegendClass(type, value, fill='', stroke='', ramp=None)
MVLegendClasses are used to define the classes listed in the legend.
- type
The type of feature to be represented by the legend class. Either 'point', 'line', 'polygon', or 'raster'.
- Type:
str, required
- fill
Valid RGB color for the fill (e.g.: '#00ff00', 'rgba(0, 255, 0, 0.5)'). Required for 'point' or 'polygon' types.
- Type:
str
- stroke
Valid RGB color for the stoke/line (e.g.: '#00ff00', 'rgba(0, 255, 0, 0.5)'). Required for 'line' types and optional for 'polygon' types.
- Type:
str
- ramp
A list of hexidecimal RGB colors that will be used to construct a color ramp. Required for 'raster' types.
- Type:
list
Example
point_class = MVLegendClass(type='point', value='Cities', fill='#00ff00') line_class = MVLegendClass(type='line', value='Roads', stroke='rbga(0,0,0,0.7)') polygon_class = MVLegendClass(type='polygon', value='Lakes', stroke='#0000aa', fill='#0000ff')
MVLegendImageClass
- class tethys_sdk.gizmos.MVLegendImageClass(value, image_url)
MVLegendImageClasses are used to define the classes listed in the legend using a pre-generated image.
Example
image_class = MVLegendImageClass(value='Cities', image_url='https://upload.wikimedia.org/wikipedia/commons/d/da/The_City_London.jpg' )
MVLegendGeoServerImageClass
- class tethys_sdk.gizmos.MVLegendGeoServerImageClass(value, geoserver_url, style, layer, width=20, height=10)
MVLegendGeoServerImageClasses are used to define the classes listed in the legend using the GeoServer generated legend.
- geoserver_url
The url to your geoserver (e.g. http://localhost:8181/geoserver).
- Type:
str, required
Example
image_class = MVLegendGeoServerImageClass(value='Cities', geoserver_url='http://localhost:8181/geoserver', style='green', layer='rivers', width=20, height=10)
MVDraw
- class tethys_sdk.gizmos.MVDraw(controls=None, initial='Pan', output_format='GeoJSON', line_color='#ffcc33', fill_color='rgba(255, 255, 255, 0.2)', point_color='#ffcc33', initial_features=None, snapping_enabled=True, snapping_options=None, snapping_layer=None, feature_selection=False, legend_title='Drawing Layer', data=None)
MVDraw objects are used to define the drawing options for Map View.
- controls
List of drawing controls to add to the map. Valid options are 'Modify', 'Delete', 'Move', 'Point', 'LineString', 'Polygon' and 'Box', 'Pan'.
- Type:
list
- initial
Drawing control to be enabled initially. Must be included in the controls list, defaults to 'Pan'.
- Type:
str
- output_format
Format to output to the hidden text area. Either 'WKT' (for Well Known Text format) or 'GeoJSON'. Defaults to 'GeoJSON'
- Type:
str
- fill_color
User control for customizing the fill color of polygons (suggest rgba format for setting transparency)
- Type:
str
- snapping_enabled
When enabled, features will be able to snap to other features on the drawing layer or in given snapping layers. Defaults to True.
- Type:
bool
- snapping_options
Supported options include edge, vertex, pixelTolerance. See: https://openlayers.org/en/latest/apidoc/module-ol_interaction_Snap.html
- Type:
dict
- snapping_layer
Dictionary with one key representing the attribute to use for identifying the layer and the value being the value to match (e.g.: {'legend_title': 'My Layer'}, {'data.my_attribute': 'value'}).
- Type:
dict
- feature_selection
Set to True to enable feature selection on the drawing layer. Defaults to False.
- Type:
bool
- legend_title
Title to display in the legend for the drawing layer. Defaults to 'Drawing Layer'.
- Type:
str
Example
drawing_options = MVDraw( controls=['Modify', 'Delete', 'Move', 'Point', 'LineString', 'Polygon', 'Box', 'Pan'], initial='Point', output_format='GeoJSON', line_color='#663399', fill_color='rgba(255,255,255,0.2)', point_color='#663399' )
MVView
- class tethys_sdk.gizmos.MVView(projection='EPSG:4326', center=None, zoom=4, maxZoom=28, minZoom=0, extent=None)
MVView objects are used to define the initial view of the Map View. The initial view is set by specifying a center and a zoom level or an extent.
- projection
Projection of the center coordinates given. This projection will be used to transform the coordinates into the default map projection (EPSG:3857).
- Type:
str
- center
An array with the coordinates of the center point of the initial view. Mutually exclusive with the "extent" argument.
- Type:
2-list<float>
- extent
The initial extent that will set the zoom level. Mutually exclusive with the "center" argument and the "zoom" argument has no effect.
- Type:
4-list<float>
Example
view_options = MVView( projection='EPSG:4326', center=[-100, 40], zoom=3.5, maxZoom=18, minZoom=2 ) view_options = MVView( projection='EPSG:4326', extent=[-100, 35, -90, 45], maxZoom=18, minZoom=2 )
JavaScript API
For advanced features, the JavaScript API can be used to interact with the OpenLayers map object that is generated by the Map View JavaScript library.
TETHYS_MAP_VIEW.getMap()
This method returns the OpenLayers map object. You can use the OpenLayers Map API version 5.3.0 to perform operations on this object such as adding layers and custom controls.
$(function() { //wait for page to load
var ol_map = TETHYS_MAP_VIEW.getMap();
ol_map.addLayer(...);
ol_map.setView(...);
});
Caution
The Map View Gizmo is powered by OpenLayers version 5.3.0 by default. When referring to the OpenLayers documentation, ensure that you are browsing the correct version of documentation (see the URL of the documentation page).
TETHYS_MAP_VIEW.updateLegend()
This method can be used to update the legend after removing/adding layers to the map.
$(function() { //wait for page to load
var ol_map = TETHYS_MAP_VIEW.getMap();
ol_map.addLayer(...);
TETHYS_MAP_VIEW.updateLegend();
});
TETHYS_MAP_VIEW.zoomToExtent(latlongextent)
This method can be used to set the view of the map to the extent provided. The extent is assumed to be given in the EPSG:4326 coordinate reference system.
$(function() { //wait for page to load
var extent = [-109.49945001309617, 37.58047995600726, -109.44540360290348, 37.679502621605735];
TETHYS_MAP_VIEW.zoomToExtent(extent);
});
TETHYS_MAP_VIEW.clearSelection()
This method applies to the WMS layer feature selection functionality. Use this method to clear the current selection via JavaScript.
TETHYS_MAP_VIEW.clearSelection();
TETHYS_MAP_VIEW.overrideSelectionStyler(geometry_type, styler)
This method applies to the WMS layer feature selection functionality. This method can be used to override the default styling for the points, lines, and polygons selected feature layers.
geometry_type (str): The type of the layer that the styler function will apply to. One of: 'points', 'lines', or 'polygons'.
styler (func): A function that accepts two arguments, feature and resolution, and returns an array of valid ol.style objects.
function my_styler(feature, resolution) {
var image, properties;
properties = feature.getProperties();
// Default icon
image = new ol.style.Circle({
radius: 5,
fill: new ol.style.Fill({
color: 'red'
})
});
if ('type' in properties) {
if (properties.type === 'TANK') {
image = new ol.style.RegularShape({
fill: new ol.style.Fill({
color: SELECTED_NODE_COLOR
}),
stroke: new ol.style.Stroke({
color: 'white',
width: 1
}),
points: 4,
radius: 14,
rotation: 0,
angle: Math.PI / 4
});
}
else if (properties.type === 'RESERVOIR') {
image = new ol.style.RegularShape({
fill: new ol.style.Fill({
color: SELECTED_NODE_COLOR
}),
stroke: new ol.style.Stroke({
color: 'white',
width: 1
}),
points: 3,
radius: 14,
rotation: 0,
angle: 0
});
}
}
return [new ol.style.Style({image: image})];
}
TETHYS_MAP_VIEW.overrideSelectionStyler('points', my_styler);
TETHYS_MAP_VIEW.onSelectionChange(callback)
This method applies to the WMS layer feature selection functionality. The callback function provided will be called each time the feature selection is changed.
callback (func): A function that accepts three arguments, points_layer, lines_layer, polygons_layer. These are handles on the OpenLayers layers that are rendering the selected features. The features are divided into three layers by type.
function my_callback(points_layer, lines_layer, polygons_layer) {
console.log(points_layer);
}
TETHYS_MAP_VIEW.onSelectionChange(my_callback);
TETHYS_MAP_VIEW.getSelectInteraction()
This method applies to the WFS/GeoJSON/KML layer feature selection functionality.
$(function() { //wait for page to load
var selection_interaction = TETHYS_MAP_VIEW.getSelectInteraction();
//when selected, print feature to developers console
selection_interaction.getFeatures().on('change:length', function(e) {
if (e.target.getArray().length > 0) {
// this means there is at least 1 feature selected
var selected_feature = e.target.item(0); // 1st feature in Collection
console.log(selected_feature);
}
});
});
TETHYS_MAP_VIEW.mapClicked(callback)
Provide a callback function to call when the map is clicked on. Only works if map_click_event parameter is set to True when defining the MapView. The function must accept two parameters an array of coordinates (lat, lon) and the click event object.
TETHYS_MAP_VIEW.mapClicked(function(coordinates, event) {
// Custom code to run whenever the map is clicked.
});
TETHYS_MAP_VIEW.clearClickedPoint()
Clear the clicked point selected by the user.
TETHYS_MAP_VIEW.clearClickedPoint();
TETHYS_MAP_VIEW.reInitializeMap()
This method is intended for initializing a map generated from an AJAX request.
Caution
This method assumes there is only one and that there will only ever be one map on the page.
Note
In order to use this, you will either need to use a MapView gizmo or import
the JavaScript/CSS libraries in the main html template page using the
import_gizmo_dependency tag in the import_gizmos block.
For example:
{% block import_gizmos %}
{% import_gizmo_dependency map_view %}
{% endblock %}
Three elements are required:
A controller for the AJAX call with a map view gizmo.
@controller(
url="dam-break/map/dam_break_map_ajax",
)
def dam_break_map_ajax(request):
"""
Controller for the dam_break_map ajax request.
"""
if request.GET:
...
#get layers
map_layer_list = ...
# Define initial view for Map View
view_options = MVView(
projection="EPSG:4326",
center=[(bbox[0]+bbox[2])/2.0, (bbox[1]+bbox[3])/2.0],
zoom=10,
maxZoom=18,
minZoom=2,
)
# Configure the map
map_options = MapView(
height="500px",
width="100%",
layers=map_layer_list,
controls=["FullScreen"],
view=view_options,
basemap=["OpenStreetMap"],
legend=True,
)
context = { "map_options": map_options }
return App.render(request, "map_ajax.html", context)
A template for with the tethys gizmo (e.g. map_ajax.html)
{% load tethys %}
{% gizmo map_options %}
The AJAX call in the javascript
$(function() { //wait for page to load
$.ajax({
url: ajax_url,
method: 'GET',
data: ajax_data,
success: function(data) {
//add new map to map div
$('#main_map_div').html(data);
TETHYS_MAP_VIEW.reInitializeMap();
}
});
});