__author__ = 'elpaso@itopen.it' __date__ = '2022-10-27' __license__ = "GPL version 3" __copyright__ = 'Copyright 2022, Gis3w' # File adapted by @rldhont and @Gustry, 3Liz import json import re from collections import namedtuple from typing import Optional from qgis.core import Qgis, QgsMapLayer, QgsProject, QgsVectorLayer from qgis.PyQt.QtCore import QBuffer, QIODevice from qgis.PyQt.QtGui import QImage from qgis.server import QgsServerFilter from lizmap_server.core import find_layer from lizmap_server.logger import Logger, exception_handler from lizmap_server.tools import to_bool Category = namedtuple( 'Category', ['ruleKey', 'checked', 'parentRuleKey', 'scaleMaxDenom', 'scaleMinDenom', 'expression', 'title']) class GetLegendGraphicFilter(QgsServerFilter): """ Add "ruleKey" to GetLegendGraphic for categorized and rule-based only works for single LAYER and STYLE(S) and JSON format. """ FEATURE_COUNT_REGEXP = r"(.*) \[≈?(?:\d+|N/A)\]" @classmethod def match_label_feature_count(cls, symbol_label: str) -> Optional[re.Match]: """Regexp for extracting the feature count from the label. """ return re.match(cls.FEATURE_COUNT_REGEXP, symbol_label) @classmethod def warning_icon(cls) -> str: """ Warning icon as base 64. """ buffer = QBuffer() buffer.open(QIODevice.WriteOnly) qp = QImage(":/images/themes/default/mIconWarning.svg") qp.save(buffer, "PNG") return bytes(buffer.data().toBase64().data()).decode() @exception_handler def responseComplete(self): handler = self.serverInterface().requestHandler() logger = Logger() if not handler: logger.critical( 'GetLegendGraphicFilter plugin cannot be run in multithreading mode, skipping.') return params = handler.parameterMap() if params.get('SERVICE', '').upper() != 'WMS': return if params.get('REQUEST', '').upper() not in ('GETLEGENDGRAPHIC', 'GETLEGENDGRAPHICS'): return if params.get('FORMAT', '').upper() != 'APPLICATION/JSON': return # Only support request for simple layer layer_name = params.get('LAYER', '') if layer_name == '': return if ',' in layer_name: # The PHP must split the request per layer return # noinspection PyArgumentList project: QgsProject = QgsProject.instance() style = params.get('STYLES', '') if not style: style = params.get('STYLE', '') show_feature_count = to_bool(params.get('SHOWFEATURECOUNT')) current_style = '' layer = find_layer(layer_name, project) if not layer: return layer: QgsMapLayer if not layer.isValid(): logger.warning( f"Layer '{layer_name}' is not valid, returning a warning icon in the legend for project " f"'{project.homePath()}'", ) json_data = { 'title': '', 'nodes': [{ 'type': 'layer', 'title': layer_name, 'icon': self.warning_icon(), 'valid': False, }], } handler.clearBody() handler.appendBody(json.dumps(json_data).encode('utf8')) return if layer.type() != QgsMapLayer.LayerType.VectorLayer: logger.info(f"Skipping the layer '{layer_name}' because it's not a vector layer") return layer: QgsVectorLayer try: current_style = layer.styleManager().currentStyle() if current_style and style and style != current_style: layer.styleManager().setCurrentStyle(style) # Force count symbol features # It seems that in QGIS Server 3.22 countSymbolFeatures is not used for JSON if show_feature_count: counter = layer.countSymbolFeatures() if counter: counter.waitForFinished() # From QGIS source code : # https://github.com/qgis/QGIS/blob/71499aacf431d3ac244c9b75c3d345bdc53572fb/src/core/symbology/qgsrendererregistry.cpp#L33 if layer.renderer().type() in ("categorizedSymbol", "RuleRenderer", "graduatedSymbol"): body = handler.body() # noinspection PyTypeChecker json_data = json.loads(bytes(body)) symbols = json_data['nodes'][0].get('symbols') if not symbols: symbols = json_data['nodes'] new_symbols = [] categories = self._extract_categories(layer, show_feature_count, project.homePath()) for idx in range(len(symbols)): symbol = symbols[idx] symbol_label = symbol['title'] if show_feature_count: match_label = self.match_label_feature_count(symbol_label) if match_label: symbol_label = match_label.group(1) else: logger.info( "GetLegendGraphic JSON: symbol label does not match '{}' '{}'".format( self.FEATURE_COUNT_REGEXP, symbol['title'])) try: category = categories[symbol_label] symbol['ruleKey'] = category.ruleKey symbol['checked'] = category.checked symbol['parentRuleKey'] = category.parentRuleKey # TODO remove when QGIS 3.28 will be the minimum version # https://github.com/qgis/QGIS/pull/53738 3.34, 3.32.1, 3.28.10 if 'scaleMaxDenom' not in symbol and category.scaleMaxDenom > 0: symbol['scaleMaxDenom'] = category.scaleMaxDenom if 'scaleMinDenom' not in symbol and category.scaleMinDenom > 0: symbol['scaleMinDenom'] = category.scaleMinDenom symbol['expression'] = category.expression if symbol['title'] != category.title: symbol['title'] = category.title except (IndexError, KeyError): pass new_symbols.append(symbol) if 'symbols' in json_data['nodes'][0]: json_data['nodes'][0]['symbols'] = new_symbols else: json_data['nodes'] = new_symbols handler.clearBody() handler.appendBody(json.dumps(json_data).encode('utf8')) except Exception as ex: logger.critical( 'Error getting layer "{}" when setting up legend graphic for json output when configuring ' 'OWS call: {}'.format(layer_name, str(ex))) finally: if layer and style and current_style and style != current_style: layer.styleManager().setCurrentStyle(current_style) @classmethod def _extract_categories( cls, layer: QgsVectorLayer, show_feature_count: bool = False, project_path: str = "", ) -> dict: """ Extract categories from the layer legend. """ # TODO Annotations QGIS 3.22 [str, Category] renderer = layer.renderer() categories = {} for item in renderer.legendSymbolItems(): # Calculate title if show_feature_count is activated # It seems that in QGIS Server 3.22 countSymbolFeatures is not used for JSON title = item.label() if show_feature_count: estimated_count = layer.dataProvider().uri().useEstimatedMetadata() count = layer.featureCount(item.ruleKey()) title += ' [{}{}]'.format( "≈" if estimated_count else "", count if count != -1 else "N/A", ) expression = '' # TODO simplify when QGIS 3.26 will be the minimum version if Qgis.QGIS_VERSION_INT >= 32600: expression, result = renderer.legendKeyToExpression(item.ruleKey(), layer) if not result: Logger.warning( f"The expression in the project '{project_path}', layer '{layer.name()}' has not " f"been generated correctly, setting the expression to an empty string", ) expression = '' if item.label() in categories.keys(): Logger.warning( f"The label key '{item.label()}' is not unique, expect the legend to be broken in the project " f"'{project_path}', layer '{layer.name()}'.", ) categories[item.label()] = Category( ruleKey=item.ruleKey(), checked=renderer.legendSymbolItemChecked(item.ruleKey()), parentRuleKey=item.parentRuleKey(), scaleMaxDenom=item.scaleMaxDenom(), scaleMinDenom=item.scaleMinDenom(), expression=expression, title=title, ) return categories