8.4.8.2. Parameter and XML

Within PyMoDAQ, Parameter state are often saved or transferred (for instance when using TCP/IP) as a XML string whose Tree structure is well adapted to represent the Parameter tree structure. Below are all the functions used to convert from a Parameter to a XML string (or file) and vice-versa.

pymodaq.utils.parameter.ioxml.XML_file_to_parameter(file_name)[source]

Convert a xml file into pyqtgraph parameter object.

Parameters	Type	Description
file_name	string	the file name of the XML file to be converted

Returns: params – a parameter list of dictionnary to init a parameter
Return type: dictionnary list

See also

walk_parameters_to_xml

Examples

pymodaq.utils.parameter.ioxml.XML_string_to_parameter(xml_string)[source]

Convert a xml string into a list of dict for initialize pyqtgraph parameter object.

Parameters	Type	Description
xml_string	string	the xml string to be converted

Returns: params
Return type: a parameter list of dict to init a parameter

See also

walk_parameters_to_xml

Examples

pymodaq.utils.parameter.ioxml.add_text_to_elt(elt, param)[source]

Add a text filed in a xml element corresponding to the parameter value

Parameters

elt (XML elt) –
param (Parameter) –

pymodaq.utils.parameter.ioxml.dict_from_param(param)[source]

Get Parameter properties as a dictionary

Parameters: param (Parameter) –
Returns: opts
Return type: dict

pymodaq.utils.parameter.ioxml.elt_to_dict(el)[source]

Convert xml element attributes to a dictionnary

Parameters: el –

pymodaq.utils.parameter.ioxml.parameter_to_xml_file(param, filename)[source]

Convert the given parameter to XML element and update the given XML file.

Parameters	Type	Description
param	instance of pyqtgraph parameter	the parameter to be added
filename	string	the filename of the XML file

See also

walk_parameters_to_xml

Examples

pymodaq.utils.parameter.ioxml.parameter_to_xml_string(param)[source]

Convert a Parameter to a XML string.

Parameters: param (Parameter) –
Returns: str
Return type: XMl string

Examples

>>> from pyqtgraph.parametertree import Parameter
>>>    #Create an instance of Parameter
>>> settings=Parameter(name='settings')
>>> converted_xml=parameter_to_xml_string(settings)
>>>    # The converted Parameter
>>> print(converted_xml)
b'<settings title="settings" type="None" />'

pymodaq.utils.parameter.ioxml.set_txt_from_elt(el, param_dict)[source]: get the value of the parameter from the text value of the xml element :param el: :type el: xml element :param param_dict: :type param_dict: dictionnary from which the parameter will be constructed

pymodaq.utils.parameter.ioxml.walk_parameters_to_xml(parent_elt=None, param=None)[source]

To convert a parameter object (and children) to xml data tree.

Parameters	Type	Description
parent_elt	XML element	the root element
param	instance of pyqtgraph parameter	Parameter object to be converted

Returns: XML element – XML element with subelements from Parameter object
Return type: parent_elt

pymodaq.utils.parameter.ioxml.walk_xml_to_parameter(params=[], XML_elt=None)[source]

To convert an XML element (and children) to list of dict enabling creation of parameter object.

Parameters	Type	Description
params	dictionnary list	the list to create parameter object
XML_elt	XML object	the XML object to be converted

Returns: params – list of dict to create parameter object
Return type: dictionnary list

Examples

>>> from pyqtgraph.parametertree import Parameter, ParameterItem
>>> import xml.etree.ElementTree as ET
>>> tree = ET.parse('text_bis.xml')
>>> root = tree.getroot()
>>> params=walk_xml_to_parameter(XML_elt=root)
>>> settings_xml=Parameter.create(name='Settings XML', type='group', children=params)
>>> settings=Parameter.create(name='Settings', type='group', children=params)

See also

walk_parameters_to_xml