1# -*- coding: utf-8 -*- 2 3""" 4*************************************************************************** 5 user.py 6 --------------------- 7 Date : January 2015 8 Copyright : (C) 2015 by Nathan Woodrow 9 Email : woodrow dot nathan at gmail dot com 10*************************************************************************** 11* * 12* This program is free software; you can redistribute it and/or modify * 13* it under the terms of the GNU General Public License as published by * 14* the Free Software Foundation; either version 2 of the License, or * 15* (at your option) any later version. * 16* * 17*************************************************************************** 18""" 19 20__author__ = 'Nathan Woodrow' 21__date__ = 'January 2015' 22__copyright__ = '(C) 2015, Nathan Woodrow' 23 24import os 25import sys 26import glob 27import traceback 28 29from qgis.PyQt.QtCore import QCoreApplication 30from qgis.core import Qgis, QgsApplication, QgsMessageLog 31 32 33def load_user_expressions(path): 34 """ 35 Load all user expressions from the given paths 36 """ 37 # Loop all py files and import them 38 modules = glob.glob(path + "/*.py") 39 names = [os.path.basename(f)[:-3] for f in modules] 40 for name in names: 41 if name == "__init__": 42 continue 43 # As user expression functions should be registered with qgsfunction 44 # just importing the file is enough to get it to load the functions into QGIS 45 try: 46 __import__("expressions.{0}".format(name), locals(), globals()) 47 except: 48 error = traceback.format_exc() 49 msgtitle = QCoreApplication.translate("UserExpressions", "User expressions") 50 msg = QCoreApplication.translate("UserExpressions", "The user expression {0} is not valid").format(name) 51 QgsMessageLog.logMessage(msg + "\n" + error, msgtitle, Qgis.Warning) 52 53 54userpythonhome = os.path.join(QgsApplication.qgisSettingsDirPath(), "python") 55expressionspath = os.path.join(userpythonhome, "expressions") 56 57sys.path.append(userpythonhome) 58 59if not os.path.exists(expressionspath): 60 os.makedirs(expressionspath) 61 62initfile = os.path.join(expressionspath, "__init__.py") 63if not os.path.exists(initfile): 64 open(initfile, "w").close() 65 66template = """from qgis.core import * 67from qgis.gui import * 68 69@qgsfunction(args='auto', group='Custom', referenced_columns=[]) 70def my_sum(value1, value2, feature, parent): 71 \"\"\" 72 Calculates the sum of the two parameters value1 and value2. 73 <h2>Example usage:</h2> 74 <ul> 75 <li>my_sum(5, 8) -> 13</li> 76 <li>my_sum(\"field1\", \"field2\") -> 42</li> 77 </ul> 78 \"\"\" 79 return value1 + value2 80""" 81 82default_expression_template = template 83 84try: 85 import expressions 86 87 expressions.load = load_user_expressions 88 expressions.load(expressionspath) 89 expressions.template = template 90except ImportError: 91 # We get a import error and crash for some reason even if we make the expressions package 92 # TODO Fix the crash on first load with no expressions folder 93 # But for now it's not the end of the world if it doesn't load the first time 94 pass 95