API

Utility functions

Dash Sylvereye provides convenient utility functions for tasks like markers generation and getting default options.

generate_markers_from_coords

Use generate_markers_from_coords to generate a Dash Sylvereye marker list out of a list of [lat, lon] coordinates.

It be imported from the dash_sylvereye.utils module.

The following example will draw a marker on top of each node in the road network:

from dash_html_components import Div
from dash_sylvereye import SylvereyeRoadNetwork
from dash_sylvereye.utils import generate_markers_from_coords

# fill a list with the coordinates of every node
# 'nodes_data' is a preloaded Dash Sylvereye nodes list
markers_coords = [[node["lat"], node["lon"]] for node in nodes_data]

# make markers out of the list of node coordinates
markers_data = generate_markers_from_coords(markers_coords)

# dashboard setup
# 'app' is the app Dash object
app.layout = Div([
    SylvereyeRoadNetwork(
                         ...                         
                         nodes_data=nodes_data,
                         markers_data=markers_data
                         ...
                        )
                         
])

The following example will draw a custom marker on top of each node in the road network. Each marker will show a tooltip with its coordinates when hovered on:

from dash_html_components import Div
from dash_sylvereye import SylvereyeRoadNetwork
from dash_sylvereye.utils import generate_markers_from_coords

CUSTOM_ICON_ID = "my_custom_marker"
CUSTOM_ICON_FILEN = "custom_marker.svg"

# fill a list with the coordinates of every node
# 'nodes_data' is a preloaded Dash Sylvereye nodes list
markers_coords = [[node["lat"], node["lon"]] for node in nodes_data]

# make tooltips out of the coordinates of every marker
markers_tooltips = [f'My coords are: {coords}' for coords in markers_coords] 

# make markers out of the list of node coordinates
markers_data = generate_markers_from_coords(markers_coords, CUSTOM_ICON_ID, CUSTOM_ICON_FILEN, markers_tooltips)

# dashboard setup
# 'app' is the app Dash object
app.layout = Div([
    SylvereyeRoadNetwork(
                         ...                         
                         nodes_data=nodes_data,
                         markers_data=markers_data
                         ...
                        )
                         
])

Parameters

Name: coords
Type: list of list

List of pairs of coordinates, one pair of [lat, lon] coordinates per marker.

Name: icon_id
Type: str
Default: 'custom_marker'

Optional custom ID for the custom icon.

Name: icon_filen
Type: str
Default: Empty string

Optional file name of a custom SVG icon which will be assigned to all markers.

Name: tooltips
Type: list of str
Default: Empty list

Optional list of tooltip strings, one tooltip string per marker.

Returns

Type: list of dict

Dash Sylvereye markers list.

get_edge_middle_coords

Use get_edge_middle_coords to get the (lat, lon) coordinates at the middle of the provided edge.

This function is useful to draw markers on top of edges.

It can be imported from the dash_sylvereye.utils module.

The following example will draw a marker at the middle point of each edge in the road network:

from dash_html_components import Div
from dash_sylvereye import SylvereyeRoadNetwork
from dash_sylvereye.utils import generate_markers_from_coords, get_edge_middle_coords

# fill a list with the coordinates at the middle of each edge
# 'edges_data' is a preloaded Dash Sylvereye edges list
marker_coords = [get_edge_middle_coords(edge['coords']) for edge in edges_data]

# make markers out of the list of edge coordinates
markers_data = generate_markers_from_coords(marker_coords)

# dashboard setup
# 'app' is the app Dash object
app.layout = Div([
    SylvereyeRoadNetwork(
                         ...                         
                         edges_data=edges_data,
                         markers_data=markers_data
                         ...
                        )
                         
])

Parameters

Name: edge
Type: list of list

The list of pairs of coordinates of an edge.

Returns

Type: list of float

The pair of coordinates located at the middle of the edge.

get_default_node_options

Use get_default_node_options to get a copy of the default node_options dictionary.

You usually first get a pre-filled default node_options dictionary by using this function, then customize the returned node_options according to your needs, and finally pass it to SylvereyeRoadNetwork through the node_options parameter.

The content of the returned node_options is as follows:

{
    "color_method": NodeColorMethod.DEFAULT,
    "color_default": 0xa10000,
    "size_method": NodeSizeMethod.DEFAULT,
    "size_default": 0.005,
    "alpha_method": NodeAlphaMethod.DEFAULT,
    "alpha_default": 1.0,
    "visibility_method": NodeVisibilityMethod.ALWAYS
}

This function can be imported from the dash_sylvereye.defaults module.

Note

This function returns a full copy of the default node_options dictionary.

Modifying the returned copy won't change the node_options dictionary returned by future calls to this function, nor the node options that come by default with the Dash Sylvereye component.

The following example employs get_default_node_options to set the alpha of all nodes to 0.5:

from dash_html_components import Div
from dash_sylvereye import SylvereyeRoadNetwork
from dash_sylvereye.defaults import get_default_node_options

# nodes options setup
node_options = get_default_node_options()
node_options['alpha_default'] = 0.5

# set the 'node_options' parameter of the SylvereyeRoadNetwork component
# 'app' is the Dash app object.
app.layout = Div([
    SylvereyeRoadNetwork(
                         ...
                         node_options=node_options,
                         ...
                        )
])

Parameters

This function has no parameters.

Returns

Type: dict

Returns a copy of the default node_options dictionary.

get_default_edge_options

Use get_default_edge_options to get a copy of the default edge_options dictionary.

You usually first get a pre-filled default edge_options dictionary by using this function, then customize the returned edge_options according to your needs, and finally pass it to SylvereyeRoadNetwork through the edge_options parameter.

The content of the returned edge_options is as follows:

{
    "color_method": EdgeColorMethod.DEFAULT,
    "color_default": 0x06696,
    "width_method": EdgeWidthMethod.DEFAULT,
    "width_default": 0.25,
    "alpha_method": EdgeAlphaMethod.DEFAULT,
    "alpha_default": 1.0,
    "alpha_min": 0.0,
    "visibility_method": EdgeVisibilityMethod.ALWAYS
}

This function can be imported from the dash_sylvereye.defaults module.

Note

This function returns a full copy of the default edge_options dictionary.

Modifying the returned copy won't change the edge_options dictionary returned by future calls to this function, nor the edge options that come by default with the Dash Sylvereye component.

The following example employs get_default_edge_options to set the alpha of all edges to 0.5:

from dash_html_components import Div
from dash_sylvereye import SylvereyeRoadNetwork
from dash_sylvereye.defaults import get_default_edge_options

# edges options setup
edge_options = get_default_edge_options()
edge_options['alpha_default'] = 0.5

# set the 'edge_options' parameter of the SylvereyeRoadNetwork component
# 'app' is the Dash app object.
app.layout = Div([
    SylvereyeRoadNetwork(
                         ...
                         edge_options=edge_options,
                         ...
                        )
])

Parameters

This function has no parameters.

Returns

Type: dict

Returns a copy of the default edge_options dictionary.

get_default_marker_options

Use get_default_marker_options to get a copy of the default marker_options dictionary.

You usually first get a pre-filled default marker_options dictionary by using this function, then customize the returned marker_options according to your needs, and finally pass it to SylvereyeRoadNetwork through the marker_options parameter.

The content of the returned marker_options is as follows:

{
    "color_method": MarkerColorMethod.DEFAULT,
    "color_default": 0x066cc,
    "icon_method": MarkerIconMethod.DEFAULT,
    "size_method": MarkerSizeMethod.DEFAULT,
    "size_default": 0.25,
    "size_default_scale_min": 0.25,
    "size_default_scale_max": 0.5,
    "alpha_method": MarkerAlphaMethod.DEFAULT,
    "alpha_default": 1.0,
    "visibility_method": MarkerVisibilityMethod.ALWAYS,
    "enable_zoom_scaling": False,
    "enable_tooltips": False
}

This function can be imported from the dash_sylvereye.defaults module.

Note

This function returns a full copy of the default marker_options dictionary.

Modifying the returned copy won't change the marker_options dictionary returned by future calls to this function, nor the marker options that come by default with the Dash Sylvereye component.

The following example employs get_default_marker_options to set the alpha of all markers to 0.5:

from dash_html_components import Div
from dash_sylvereye import SylvereyeRoadNetwork
from dash_sylvereye.defaults import get_default_marker_options

# markers options setup
marker_options = get_default_marker_options()
marker_options['alpha_default'] = 0.5

# set the 'marker_options' parameter of the SylvereyeRoadNetwork component
# 'app' is the Dash app object.
app.layout = Div([
    SylvereyeRoadNetwork(
                         ...
                         marker_options=marker_options,
                         ...
                        )
])

Parameters

This function has no parameters.

Returns

Type: dict

Returns a copy of the default marker_options dictionary.

TODO: debug_options

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