QGIS/python/plugins/processing/algs/qgis/PointsLayerFromTable.py

# -*- coding: utf-8 -*-

"""
***************************************************************************
    PointsLayerFromTable.py
    ---------------------
    Date                 : January 2013
    Copyright            : (C) 2013 by Victor Olaya
    Email                : volayaf at gmail dot com
***************************************************************************
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
***************************************************************************
"""

__author__ = 'Victor Olaya'
__date__ = 'August 2013'
__copyright__ = '(C) 2013, Victor Olaya'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

from qgis.core import (QgsApplication,
                       QgsWkbTypes,
                       QgsPoint,
                       QgsFeatureRequest,
                       QgsGeometry,
                       QgsProcessingParameterDefinition,
                       QgsProcessingParameterFeatureSink,
                       QgsProcessingParameterFeatureSource,
                       QgsProcessingParameterCrs,
                       QgsProcessingOutputVectorLayer,
                       QgsProcessingParameterField)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm


class PointsLayerFromTable(QgisAlgorithm):

    INPUT = 'INPUT'
    XFIELD = 'XFIELD'
    YFIELD = 'YFIELD'
    ZFIELD = 'ZFIELD'
    MFIELD = 'MFIELD'
    OUTPUT = 'OUTPUT'
    TARGET_CRS = 'TARGET_CRS'

    def icon(self):
        return QgsApplication.getThemeIcon("/providerQgis.svg")

    def svgIconPath(self):
        return QgsApplication.iconPath("providerQgis.svg")

    def tags(self):
        return self.tr('points,create,values,attributes').split(',')

    def group(self):
        return self.tr('Vector creation tools')

    def __init__(self):
        super().__init__()

        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT, self.tr('Input layer'), types=[QgsProcessingParameterField.TypeTable]))

        self.addParameter(QgsProcessingParameterField(self.XFIELD,
                                                      self.tr('X field'), parentLayerParameterName=self.INPUT, type=QgsProcessingParameterField.Any))
        self.addParameter(QgsProcessingParameterField(self.YFIELD,
                                                      self.tr('Y field'), parentLayerParameterName=self.INPUT, type=QgsProcessingParameterField.Any))
        self.addParameter(QgsProcessingParameterField(self.ZFIELD,
                                                      self.tr('Z field'), parentLayerParameterName=self.INPUT, type=QgsProcessingParameterField.Any, optional=True))
        self.addParameter(QgsProcessingParameterField(self.MFIELD,
                                                      self.tr('M field'), parentLayerParameterName=self.INPUT, type=QgsProcessingParameterField.Any, optional=True))
        self.addParameter(QgsProcessingParameterCrs(self.TARGET_CRS,
                                                    self.tr('Target CRS'), defaultValue='EPSG:4326'))

        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Points from table'), type=QgsProcessingParameterDefinition.TypeVectorPoint))
        self.addOutput(QgsProcessingOutputVectorLayer(self.OUTPUT, self.tr('Points from table'), type=QgsProcessingParameterDefinition.TypeVectorPoint))

        self.source = None
        self.x_field_index = None
        self.y_field_index = None
        self.z_field_index = None
        self.m_field_index = None
        self.sink = None
        self.dest_id = None

    def name(self):
        return 'createpointslayerfromtable'

    def displayName(self):
        return self.tr('Create points layer from table')

    def prepareAlgorithm(self, parameters, context, feedback):
        self.source = self.parameterAsSource(parameters, self.INPUT, context)

        fields = self.source.fields()
        self.x_field_index = fields.lookupField(self.parameterAsString(parameters, self.XFIELD, context))
        self.y_field_index = fields.lookupField(self.parameterAsString(parameters, self.YFIELD, context))
        self.z_field_index = -1
        if self.parameterAsString(parameters, self.ZFIELD, context):
            self.z_field_index = fields.lookupField(self.parameterAsString(parameters, self.ZFIELD, context))
        self.m_field_index = -1
        if self.parameterAsString(parameters, self.MFIELD, context):
            self.m_field_index = fields.lookupField(self.parameterAsString(parameters, self.MFIELD, context))

        wkb_type = QgsWkbTypes.Point
        if self.z_field_index >= 0:
            wkb_type = QgsWkbTypes.addZ(wkb_type)
        if self.m_field_index >= 0:
            wkb_type = QgsWkbTypes.addM(wkb_type)

        target_crs = self.parameterAsCrs(parameters, self.TARGET_CRS, context)

        (self.sink, self.dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
                                                         fields, wkb_type, target_crs)
        return True

    def processAlgorithm(self, context, feedback):
        request = QgsFeatureRequest().setFlags(QgsFeatureRequest.NoGeometry)
        features = self.source.getFeatures(request)
        total = 100.0 / self.source.featureCount() if self.source.featureCount() else 0

        for current, feature in enumerate(features):
            if feedback.isCanceled():
                break

            feedback.setProgress(int(current * total))
            attrs = feature.attributes()

            try:
                x = float(attrs[self.x_field_index])
                y = float(attrs[self.y_field_index])

                point = QgsPoint(x, y)

                if self.z_field_index >= 0:
                    try:
                        point.addZValue(float(attrs[self.z_field_index]))
                    except:
                        point.addZValue(0.0)

                if self.m_field_index >= 0:
                    try:
                        point.addMValue(float(attrs[self.m_field_index]))
                    except:
                        point.addMValue(0.0)

                feature.setGeometry(QgsGeometry(point))
            except:
                pass  # no geometry

            self.sink.addFeature(feature)
        return True

    def postProcessAlgorithm(self, context, feedback):
        return {self.OUTPUT: self.dest_id}