Merge pull request Pyomo#3271 from eslickj/vmodel

Add a model viewer option to specify the model by variable name in __main__

pyomo/contrib/viewer/README.md

@@ -42,6 +42,24 @@ ui = get_mainwindow(model=model)
 # Do model things, the viewer will stay in sync with the Pyomo model
 ```
 
+If you are working in Jupyter notebook, Jupyter qtconsole, or other Jupyter-
+based IDEs, and your model is in the __main__ namespace (this is the usual case),
+you can specify the model by its variable name as below.  The advantage of this
+is that if you replace the model with a new model having the same variable name,
+the UI will automatically update without having to manually reset the model pointer.
+
+```python
+%gui qt  #Enables IPython's GUI event loop integration.
+# Execute the above in its own cell and wait for it to finish before moving on.
+from pyomo.contrib.viewer.ui import get_mainwindow
+import pyomo.environ as pyo
+
+model = pyo.ConcreteModel() # could import an existing model here
+ui = get_mainwindow(model_var_name_in_main="model")
+
+# Do model things, the viewer will stay in sync with the Pyomo model
+```
+
 **Note:** the ```%gui qt``` cell must be executed in its own cell and execution
 must complete before running any other cells (you can't use "run all").
 

pyomo/contrib/viewer/model_select.py

@@ -60,31 +60,33 @@ def select_model(self):
         items = self.tableWidget.selectedItems()
         if len(items) == 0:
             return
-        self.ui_data.model = self.models[items[0].row()]
+        self.ui_data.model_var_name_in_main = self.models[items[0].row()][1]
+        self.ui_data.model = self.models[items[0].row()][0]
         self.close()
 
     def update_models(self):
         import __main__
 
-        s = __main__.__dict__
+        s = dir(__main__)
         keys = []
         for k in s:
-            if isinstance(s[k], pyo.Block):
+            if isinstance(getattr(__main__, k), pyo.Block):
                 keys.append(k)
         self.tableWidget.clearContents()
         self.tableWidget.setRowCount(len(keys))
         self.models = []
         for row, k in enumerate(sorted(keys)):
+            model = getattr(__main__, k)
             item = myqt.QTableWidgetItem()
             item.setText(k)
             self.tableWidget.setItem(row, 0, item)
             item = myqt.QTableWidgetItem()
             try:
-                item.setText(s[k].name)
+                item.setText(model.name)
             except:
                 item.setText("None")
             self.tableWidget.setItem(row, 1, item)
             item = myqt.QTableWidgetItem()
-            item.setText(str(type(s[k])))
+            item.setText(str(type(model)))
             self.tableWidget.setItem(row, 2, item)
-            self.models.append(s[k])
+            self.models.append((model, k))

pyomo/contrib/viewer/pyomo_viewer.py

@@ -41,7 +41,7 @@ class QtApp(
         model
     except NameError:
         model=None
-    ui, model = get_mainwindow(model=model, ask_close=False)
+    ui = get_mainwindow(model=model, ask_close=False)
 ui.setWindowTitle('Pyomo Model Viewer -- {}')"""
 
     _kernel_cmd_hide_ui = """try:

pyomo/contrib/viewer/tests/test_qt.py

@@ -103,7 +103,7 @@ def blackbox(a, b):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_get_mainwindow(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     assert hasattr(mw, "menuBar")
     assert isinstance(mw.variables, ModelBrowser)
     assert isinstance(mw.constraints, ModelBrowser)
@@ -113,13 +113,13 @@ def test_get_mainwindow(qtbot):
 
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_close_mainwindow(qtbot):
-    mw, m = get_mainwindow(model=None, testing=True)
+    mw = get_mainwindow(model=None, testing=True)
     mw.exit_action()
 
 
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_show_model_select_no_models(qtbot):
-    mw, m = get_mainwindow(model=None, testing=True)
+    mw = get_mainwindow(model=None, testing=True)
     ms = mw.show_model_select()
     ms.update_models()
     ms.select_model()
@@ -128,7 +128,7 @@ def test_show_model_select_no_models(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_model_information(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     mw.model_information()
     assert isinstance(mw._dialog, QMessageBox)
     text = mw._dialog.text()
@@ -149,15 +149,15 @@ def test_model_information(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_tree_expand_collapse(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     mw.variables.treeView.expandAll()
     mw.variables.treeView.collapseAll()
 
 
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_residual_table(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     mw.residuals_restart()
     mw.ui_data.calculate_expressions()
     mw.residuals.calculate()
@@ -184,7 +184,7 @@ def test_residual_table(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_var_tree(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     qtbot.addWidget(mw)
     mw.variables.treeView.expandAll()
     root_index = mw.variables.datmodel.index(0, 0)
@@ -218,7 +218,7 @@ def test_var_tree(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_bad_view(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     err = None
     try:
         mw.badTree = mw._tree_restart(

pyomo/contrib/viewer/ui.py

@@ -66,7 +66,9 @@ class _MainWindow(object):
     _log.error(_err)
 
 
-def get_mainwindow(model=None, show=True, ask_close=True, testing=False):
+def get_mainwindow(
+    model=None, show=True, ask_close=True, model_var_name_in_main=None, testing=False
+):
     """
     Create a UI MainWindow.
 
@@ -79,16 +81,32 @@ def get_mainwindow(model=None, show=True, ask_close=True, testing=False):
         (ui, model): ui is the MainWindow widget, and model is the linked Pyomo
             model.  If no model is provided a new ConcreteModel is created
     """
+    model_name = model_var_name_in_main
     if model is None:
-        model = pyo.ConcreteModel(name="Default")
-    ui = MainWindow(model=model, ask_close=ask_close, testing=testing)
+        import __main__
+
+        if model_name in dir(__main__):
+            if isinstance(getattr(__main__, model_name), pyo.Block):
+                model = getattr(__main__, model_name)
+        else:
+            for s in dir(__main__):
+                if isinstance(getattr(__main__, s), pyo.Block):
+                    model = getattr(__main__, s)
+                    model_name = s
+                    break
+    ui = MainWindow(
+        model=model,
+        model_var_name_in_main=model_name,
+        ask_close=ask_close,
+        testing=testing,
+    )
     try:
         get_ipython().events.register("post_execute", ui.refresh_on_execute)
     except AttributeError:
         pass  # not in ipy kernel, so is fine to not register callback
     if show:
         ui.show()
-    return ui, model
+    return ui
 
 
 class MainWindow(_MainWindow, _MainWindowUI):
@@ -97,6 +115,7 @@ def __init__(self, *args, **kwargs):
         main = self.main = kwargs.pop("main", None)
         ask_close = self.ask_close = kwargs.pop("ask_close", True)
         self.testing = kwargs.pop("testing", False)
+        model_var_name_in_main = kwargs.pop("model_var_name_in_main", None)
         flags = kwargs.pop("flags", 0)
         self.ui_data = UIData(model=model)
         super().__init__(*args, **kwargs)
@@ -128,6 +147,7 @@ def __init__(self, *args, **kwargs):
         self.actionCalculateExpressions.triggered.connect(
             self.ui_data.calculate_expressions
         )
+        self.ui_data.model_var_name_in_main = model_var_name_in_main
         self.actionTile.triggered.connect(self.mdiArea.tileSubWindows)
         self.actionCascade.triggered.connect(self.mdiArea.cascadeSubWindows)
         self.actionTabs.triggered.connect(self.toggle_tabs)
@@ -256,6 +276,18 @@ def refresh_on_execute(self):
         ipython kernel.  The main purpose of this right now it to refresh the
         UI display so that it matches the current state of the model.
         """
+        if self.ui_data.model_var_name_in_main is not None:
+            import __main__
+
+            try:
+                mname = self.ui_data.model_var_name_in_main
+                mid = id(getattr(__main__, mname))
+                if id(self.ui_data.model) != mid:
+                    self.ui_data.model = getattr(__main__, mname)
+                    self.update_model
+                    return
+            except AttributeError:
+                pass
         for w in self._refresh_list:
             try:
                 w.refresh()

pyomo/contrib/viewer/ui_data.py

@@ -39,16 +39,27 @@ class UIDataNoUi(object):
     UIData.  The class is split this way for testing when PyQt is not available.
     """
 
-    def __init__(self, model=None):
+    def __init__(self, model=None, model_var_name_in_main=None):
         """
         This class holds the basic UI setup, but doesn't depend on Qt. It
         shouldn't really be used except for testing when Qt is not available.
 
         Args:
             model: The Pyomo model to view
+            model_var_name_in_main: if this is set, check that the model variable
+                which points to a model object in __main__ has the same id when
+                the UI is refreshed due to a command being executed in jupyter
+                notebook or QtConsole, if not the same id, then update the model
+                Since the model viewer is not necessarily pointed at a model in the
+                __main__ namespace only set this if you want the model to auto
+                update.  Since the model selector dialog lets you choose models
+                from the __main__ namespace it sets this when you select a model.
+                This is useful if you run a script repeatedly that replaces a model
+                preventing you from looking at a previous version of the model.
         """
         super().__init__()
         self._model = None
+        self.model_var_name_in_main = model_var_name_in_main
         self._begin_update = False
         self.value_cache = ComponentMap()
         self.value_cache_units = ComponentMap()