APED_Device/xml_reader.py
2021-01-07 19:28:34 +01:00

101 lines
3.3 KiB
Python

from lxml import etree
class Xml_reader:
""" reader for the XML configuration """
def __init__(self, xml_path: str, xsd_path: str):
"""inits the reader
Args:
xml_path (str): the path to the XML file
xsd_path (str): the path to the XSD file
Raises:
SyntaxError: validity of XML file is checked with the XSD file
"""
if not self.validate(xml_path,xsd_path): #validate XML file
raise SyntaxError('the XML config file has an invalid syntax')
self.set_root(xml_path)
def set_root(self, xml_path: str):
"""method to read and store the root element from the XML file
Args:
xml_path (str): the path to the XML file
"""
self.root = etree.parse(xml_path).getroot()
def validate(self, xml_path: str, xsd_path: str) -> bool:
"""validates a XML by using a XSD file
Args:
xml_path (str): the path to the XML file
xsd_path (str): the path to the XSD file
Returns:
bool: result of the validation
"""
xml_schema = etree.XMLSchema(etree.parse(xsd_path))
return xml_schema.validate(etree.parse(xml_path))
def get_device_names(self) -> list:
"""lists all the device names from the config XML
Returns:
list: all device names as strings
"""
return [device.get("name") for device in self.root.findall('Device')]
def get_buffer_size(self, device_name:str) -> int:
"""method to read the buffer size of a given device from the XML
Args:
device_name (str): the name of a device
Raises:
NameError: device_name will be checked against the config XML
Returns:
int: the buffer size for the device
"""
if self.root.find("Device[@name='%s']" % device_name) is None:
raise NameError("unknown device %s" % device_name)
buffer_size = self.root.find(
"Device[@name='%s']" % device_name).get("buffer_size")
return buffer_size if buffer_size != None else 0
def get_port(self,device_name:str) -> dict:
"""returns the information about a port of a given device
Args:
device_name (str): the name of a device
Returns:
dict: {'protocol', [list: pins]}
Raises:
NameError: device_name will be checked against the config XML
"""
if self.root.find("Device[@name='%s']" % device_name) is None:
raise NameError("unknown device %s" % device_name)
port = self.root.find(
"Device[@name='%s']/Port" % device_name)
return {
'protocol': port.get('protocol'),
'frequency':
port.get('frequency') if port.get('frequency') != None else '',
'pins': [
pin.text for pin in self.root.findall(
"Device[@name='%s']/Port/Pin" % device_name
)
]
}
# ##test
# xml_reader = Xml_reader('XML/Test.xml','XML/config.xsd')
# print(xml_reader.get_device_names)
# print(xml_reader.get_port("example"))
# print(xml_reader.get_port("PWM_example"))
# print(xml_reader.get_port("sensorarray"))
# print(xml_reader.get_buffer_size("PWM_example"))
# print(xml_reader.get_buffer_size("example"))