PyQt4: How to load compiled ui-files correctly? - qt

Question

I created a Qt resource file with all my ui files inside of it, I compiled that with pyrcc4 command-line in a python file, and then I loaded the ui files using loadUi. Here an example:
#!/usr/bin/env python
#-*- coding:utf-8 -*-
import os
import sys
from PyQt4.QtCore import Qt, QFile
from PyQt4.uic import loadUi
from PyQt4.QtGui import QDialog
from xarphus.gui import ui_rc
# I import the compiled qt resource file named ui_rc
BASE_PATH = os.path.dirname(os.path.abspath(__file__))
#UI_PATH = os.path.join(BASE_PATH, 'gui', 'create_user.ui')
UI_PATH = QFile(":/ui_file/create_user.ui")
# I want to load those compiled ui files,
# so I just create QFile.
class CreateUser_Window(QDialog):
def __init__(self, parent):
QDialog.__init__(self, parent)
# I open the created QFile
UI_PATH.open(QFile.ReadOnly)
# I read the QFile and load the ui file
self.ui_create_user = loadUi(UI_PATH, self)
# After then I close it
UI_PATH.close()
Well its works fine, but I have a problem. When I open the GUI-window once, everything works fine. After closing the window I try to open the same GUI-window again, I get ja long traceback.
Traceback (most recent call last): File "D:\Dan\Python\xarphus\xarphus\frm_mdi.py", line 359, in
create_update_form self.update_form = Update_Window(self) File
"D:\Dan\Python\xarphus\xarphus\frm_update.py", line 135, in init
self.ui_update = loadUi(UI_PATH, self) File
"C:\Python27\lib\site-packages\PyQt4\uic__init__.py", line 238, in
loadUi return DynamicUILoader(package).loadUi(uifile, baseinstance,
resource_suffix) File
"C:\Python27\lib\site-packages\PyQt4\uic\Loader\loader.py", line 71,
in loadUi return self.parse(filename, resource_suffix, basedir) File
"C:\Python27\lib\site-packages\PyQt4\uic\uiparser.py", line 984, in
parse document = parse(filename) File
"C:\Python27\lib\xml\etree\ElementTree.py", line 1182, in parse
tree.parse(source, parser) File
"C:\Python27\lib\xml\etree\ElementTree.py", line 657, in parse
self._root = parser.close() File
"C:\Python27\lib\xml\etree\ElementTree.py", line 1654, in close
self._raiseerror(v) File "C:\Python27\lib\xml\etree\ElementTree.py",
line 1506, in _raiseerror raise err xml.etree.ElementTree.ParseError:
no element found: line 1, column 0
Can everyone help me?

Answer 1

Maybe I have a solution, but I don't know if that is a perfectly pythonic.
Well, we know all python projects have an __ init __-file. We need it for initializing Python packages, right? Well I thought: Why not use this file? What did I do? I define in the __ init __ -file a function like so:
#!/usr/bin/env python
#-*- coding:utf-8 -*-
from PyQt4.uic import loadUi
from PyQt4.QtCore import Qt, QFile
def ui_load_about(self):
uiFile = QFile(":/ui_file/about.ui")
uiFile.open(QFile.ReadOnly)
self.ui_about = loadUi(uiFile)
uiFile.close()
return self.ui_about
Now in my "About_Window"-class I do this:
#!/usr/bin/env python
#-*- coding:utf-8 -*-
import os
import sys
from PyQt4.QtCore import Qt, QFile
from PyQt4.uic import loadUi
from PyQt4.QtGui import QDialog
import __init__ as ui_file
class About_Window(QDialog):
def __init__(self, parent):
QDialog.__init__(self, parent)
self.ui_about = ui_file.ui_load_about(self)
You see I importe the package-file (__ init __-file) as ui_file and then I call the function and save the return of the function in the variable self.ui_about.
In my case I open the About_Window from a MainWindow(QMainWindow), and it looks like so:
def create_about_form(self):
self.ui_about = About_Window(self)
# Now when I try to show (show()-method) a window I get two windows
# The reason is: I open and load the ui files from compiled
# qt resorce file that was define in __init__-module.
# There is a function that opens the resource file, reads
# the ui file an closes and returns the ui file back
# That's the reason why I have commented out this method
#self.ui_about.show()
You see I commented out the show()-method. It works without this method. I only define the About_Window()-class. Well I know that isn't maybe the best solution, but it works. I can open the window again and again without traceback.
If you have a better solution or idea let me know :-)