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_gui.parameter.ioxml.XML_file_to_parameter(file_name)

Convert a xml file into pyqtgraph parameter object.

Returns:

params – a list of dictionary defining a Parameter object and its children

Return type:

list

See also

walk_parameters_to_xml

Examples

pymodaq_gui.parameter.ioxml.XML_string_to_parameter(xml_string)

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

pymodaq_gui.parameter.ioxml.add_text_to_elt(elt, param)

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

Parameters:

• elt (XML elt)

• param (Parameter)

See also

add_text_to_elt, walk_parameters_to_xml, dict_from_param

pymodaq_gui.parameter.ioxml.dict_from_param(param)

Get Parameter properties as a dictionary

Parameters:

param (Parameter)

Returns:

opts

Return type:

dict

See also

add_text_to_elt, walk_parameters_to_xml, dict_from_param

pymodaq_gui.parameter.ioxml.elt_to_dict(el)

Convert xml element attributes to a dictionnary

Parameters:

el

pymodaq_gui.parameter.ioxml.parameter_to_xml_file(param, filename, overwrite=True)

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
overwrite	boolean	raise Error is False and file exists

See also

walk_parameters_to_xml

Examples

pymodaq_gui.parameter.ioxml.parameter_to_xml_string(param)

Convert a Parameter to a XML string.

Parameters:

param (Parameter)

Returns:

str

Return type:

XMl string

See also

add_text_to_elt, walk_parameters_to_xml, dict_from_param

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_gui.parameter.ioxml.set_txt_from_elt(el, param_dict)

get the value of the parameter from the text value of the xml element :type el: xml element :param el: :type el: xml element :type param_dict: dictionnary from which the parameter will be constructed :param param_dict: :type param_dict: dictionnary from which the parameter will be constructed

pymodaq_gui.parameter.ioxml.walk_parameters_to_xml(parent_elt=None, param=None)

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

See also

add_text_to_elt, walk_parameters_to_xml, dict_from_param

pymodaq_gui.parameter.ioxml.walk_xml_to_parameter(params=[], XML_elt=None)

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