widgets.py

import warnings

from django import forms
from django.contrib.gis.forms.widgets import BaseGeometryWidget
from django.core import validators
from django.template.defaultfilters import slugify
from django.templatetags.static import static

from leaflet import app_settings, PLUGINS, PLUGIN_FORMS


class LeafletWidget(BaseGeometryWidget):
    template_name = 'leaflet/widget.html'
    map_srid = 4326
    modifiable = True
    supports_3d = False
    include_media = False
    settings_overrides = {}
    csp_nonce = None

    @property
    def media(self):
        if not self.include_media:
            return forms.Media()

        # We assume that including media for widget means there is
        # no Leaflet at all in the page.
        js = [
            'leaflet/leaflet.js',
            'leaflet/leaflet.extras.js',
            *PLUGINS[PLUGIN_FORMS]['js'],
        ]
        css = ['leaflet/leaflet.css'] + PLUGINS[PLUGIN_FORMS]['css']
        return forms.Media(js=js, css={'screen': css})

    def serialize(self, value):
        return value.geojson if value else ''

    def _get_attrs(self, name, attrs=None):
        """Get additional attributes for template context

        Some important attributes needed for rendering the map widget
        are not part of the widget context but rather of the global
        template context.
        When using e.g. :class:`django.forms.MultiWidget`, this global
        context will not be accessible. For this reason, this method
        has been made public so that it can be used in custom multi
        widgets.

        .. deprecated:: 0.28.1
           Use :meth:`.get_attrs` instead.
        """
        warnings.warn(
            'Method \'LeafletWidget._get_attrs\' has been deprecated. Consider calling '
            '\'LeafletWidget.get_attrs\' instead.',
            DeprecationWarning
        )
        return self.get_attrs(name, attrs=attrs)

    def get_attrs(self, name, attrs=None):
        assert self.map_srid == 4326, 'Leaflet vectors should be decimal degrees.'

        # Retrieve params from Field init (if any)
        self.geom_type = self.attrs.get('geom_type', self.geom_type)
        self.settings_overrides = self.attrs.get('settings_overrides', self.settings_overrides)

        # Setting 'loadevent' added in the widget constructor
        loadevent = self.attrs.get('loadevent', app_settings.get('LOADEVENT'))

        attrs = attrs or {}

        # In BaseGeometryWidget, geom_type is set using gdal, and fails with generic.
        # See https://code.djangoproject.com/ticket/21021
        if self.geom_type == 'GEOMETRY':
            attrs['geom_type'] = 'Geometry'

        map_id_css = slugify(attrs.get('id', name))  # id need to have - for the inline formset to replace the prefix
        map_id = map_id_css.replace('-', '_')  # JS-safe
        attrs.update(id=map_id,
                     id_css=map_id_css,
                     module='geodjango_%s' % map_id,
                     id_map=map_id_css + '-map',
                     id_map_callback=map_id + '_map_callback',
                     loadevent=loadevent,
                     modifiable=self.modifiable,
                     target_map=attrs.get('target_map', getattr(self, 'target_map', None)),
                     settings_overrides=attrs.get('settings_overrides', getattr(self, 'settings_overrides', None)),
                     geometry_field_class=attrs.get('geometry_field_class', getattr(self, 'geometry_field_class', 'L.GeometryField')),
                     field_store_class=attrs.get('field_store_class', getattr(self, 'field_store_class', 'L.FieldStore')))
        return attrs

    def get_context(self, name, value, attrs):
        value = None if value in validators.EMPTY_VALUES else value
        context = super().get_context(name, value, attrs)
        context.update(self.get_attrs(name, attrs))
        context["csp_nonce"] = self.csp_nonce
        context["FORCE_IMAGE_PATH"] = app_settings.get('FORCE_IMAGE_PATH')
        context["reset_view_icon"] = static("leaflet/images/reset-view.png")
        return context