src/eric7/EricXML/XMLStreamReaderBase.py

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

# Copyright (c) 2010 - 2022 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a base class for all of eric7s XML stream writers.
"""

import base64
import pickle  # secok

from PyQt6.QtCore import QCoreApplication, QXmlStreamReader

from eric7.EricWidgets import EricMessageBox


class XMLStreamReaderBase(QXmlStreamReader):
    """
    Class implementing a base class for all of eric7s XML stream readers.
    """

    def __init__(self, device):
        """
        Constructor

        @param device reference to the I/O device to read from (QIODevice)
        """
        super().__init__(device)

    def toBool(self, value):
        """
        Public method to convert the given value to bool.

        @param value value to be converted ("True", "False", "1", "0")
        @return converted value (boolean) or None in case of an error
        """
        if value.lower() in ["true", "false"]:
            return value.lower() == "true"

        if value in ["1", "0"]:
            return bool(int(value))

        self.raiseBadValue(value)
        return None

    def showErrorMessage(self):
        """
        Public method to show an error message.
        """
        if self.hasError():
            if self.device() is not None:
                msg = QCoreApplication.translate(
                    "XMLStreamReaderBase",
                    "<p>XML parse error in file <b>{0}</b>, line {1},"
                    " column {2}</p><p>Error: {3}</p>",
                ).format(
                    self.device().fileName(),
                    self.lineNumber(),
                    self.columnNumber(),
                    self.errorString(),
                )
            else:
                msg = QCoreApplication.translate(
                    "XMLStreamReaderBase",
                    "<p>XML parse error (line {0}, column {1})</p><p>Error: {2}</p>",
                ).format(self.lineNumber(), self.columnNumber(), self.errorString())
            EricMessageBox.warning(
                None,
                QCoreApplication.translate("XMLStreamReaderBase", "XML parse error"),
                msg,
            )

    def raiseUnexpectedStartTag(self, tag):
        """
        Public method to raise an error for an unexpected start tag.

        @param tag name of the unexpected tag (string)
        """
        self.raiseError(
            QCoreApplication.translate(
                "XMLStreamReaderBase", "Unexpected start tag '{0}'.".format(tag)
            )
        )

    def raiseUnsupportedFormatVersion(self, version):
        """
        Public method to raise an error for an unsupported file format version.

        @param version unsupported version (string)
        """
        self.raiseError(
            QCoreApplication.translate(
                "XMLStreamReaderBase", "File format version '{0}' is not supported."
            ).format(version)
        )

    def raiseBadValue(self, value):
        """
        Public method to raise an error for a bad value.

        @param value bad value (string)
        """
        self.raiseError(
            QCoreApplication.translate("XMLStreamReaderBase", "Bad value: {0}").format(
                value
            )
        )

    def readXML(self):
        """
        Public method to read and parse the XML document.
        """
        pass

    def attribute(self, name, default=""):
        """
        Public method to read the given attribute of the current tag.

        @param name name of the attribute (string)
        @param default default value (string)
        @return value of the requested tag attribute (string)
        """
        try:
            att = self.attributes().value(name)
            if att == "":
                att = default
            return att
        except AttributeError:
            # Work around for PyQt6 < 6.1.1
            attributes = self.attributes()
            for attribute in attributes:
                if attribute.name() == name:
                    value = attribute.value()
                    if not value:
                        value = default
                    break
            else:
                value = default
            return value

    def _skipUnknownElement(self):
        """
        Protected method to skip over all unknown elements.
        """
        if not self.isStartElement():
            return

        while not self.atEnd():
            self.readNext()
            if self.isEndElement():
                break

            if self.isStartElement():
                self._skipUnknownElement()

    def _readBasics(self):
        """
        Protected method to read an object of a basic Python type.

        @return Python object read
        """
        while not self.atEnd():
            self.readNext()
            if self.isStartElement():
                try:
                    if self.name() == "none":
                        val = None
                    elif self.name() in ("int", "long"):
                        val = int(self.readElementText())
                    elif self.name() == "bool":
                        b = self.readElementText()
                        if b == "True":
                            val = True
                        else:
                            val = False
                    elif self.name() == "float":
                        val = float(self.readElementText())
                    elif self.name() == "complex":
                        real, imag = self.readElementText().split()
                        val = float(real) + float(imag) * 1j
                    elif self.name() == "string":
                        val = self.readElementText()
                    elif self.name() == "bytes":
                        by = bytes([int(b) for b in self.readElementText().split(",")])
                        val = by
                    elif self.name() == "bytearray":
                        by = bytearray(
                            [int(b) for b in self.readElementText().split(",")]
                        )
                        val = by
                    elif self.name() == "tuple":
                        val = self.__readTuple()
                        return val
                    elif self.name() == "list":
                        val = self.__readList()
                        return val
                    elif self.name() == "dict":
                        val = self.__readDict()
                        return val
                    elif self.name() == "set":
                        val = self.__readSet()
                        return val
                    elif self.name() == "frozenset":
                        val = self.__readFrozenset()
                        return val
                    elif self.name() == "pickle":
                        encoding = self.attribute("encoding")
                        if encoding != "base64":
                            self.raiseError(
                                QCoreApplication.translate(
                                    "XMLStreamReaderBase",
                                    "Pickle data encoding '{0}' is not supported.",
                                ).format(encoding)
                            )
                            continue
                        b64 = self.readElementText()
                        pic = base64.b64decode(b64.encode("ASCII"))
                        val = pickle.loads(pic)  # secok
                    else:
                        self._skipUnknownElement()
                except ValueError as err:
                    self.raiseError(str(err))
                    continue

            if self.isEndElement():
                if self.name() in ["tuple", "list", "dict", "set", "frozenset"]:
                    return None
                else:
                    return val

    def __readTuple(self):
        """
        Private method to read a Python tuple.

        @return Python tuple
        """
        li = []
        while not self.atEnd():
            val = self._readBasics()
            if self.isEndElement() and self.name() == "tuple" and val is None:
                return tuple(li)
            else:
                li.append(val)

    def __readList(self):
        """
        Private method to read a Python list.

        @return Python list
        """
        li = []
        while not self.atEnd():
            val = self._readBasics()
            if self.isEndElement() and self.name() == "list" and val is None:
                return li
            else:
                li.append(val)

    def __readDict(self):
        """
        Private method to read a Python dictionary.

        @return Python dictionary
        """
        d = {}
        while not self.atEnd():
            self.readNext()
            if self.isStartElement():
                if self.name() == "key":
                    key = self._readBasics()
                elif self.name() == "value":
                    d[key] = self._readBasics()
                    if self.isEndElement() and self.name() == "dict":
                        self.readNext()

            if self.isEndElement() and self.name() == "dict":
                return d

    def __readSet(self):
        """
        Private method to read a Python set.

        @return Python set
        """
        li = []
        while not self.atEnd():
            val = self._readBasics()
            if self.isEndElement() and self.name() == "set" and val is None:
                return set(li)
            else:
                li.append(val)

    def __readFrozenset(self):
        """
        Private method to read a Python set.

        @return Python set
        """
        li = []
        while not self.atEnd():
            val = self._readBasics()
            if self.isEndElement() and self.name() == "frozenset" and val is None:
                return frozenset(li)
            else:
                li.append(val)