ver: 1.002

tcl bug in Mac os
Porting to Windows...

Author: martdev1963

Diff for: frontend.py

@@ -0,0 +1,188 @@
+"""----------------------------------------------------------------------------------------------------------------------------------------
+                                        /////////////////////////////////////////////////////
+                                        /                   **FRONT-END**                   /
+                                        /                 **DOCUMENTATION**                 /
+                                        /    Martin Batista - python progrmr  07/24/2018    /
+                                        /////////////////////////////////////////////////////
+FRONT-END: tKinter GUI
+BACK-END: Sqlite3
+*FEATURES/REQUIREMENTS*
+
+A program that stores this book information:
+Title, Author
+Year, ISBN
+
+User can:
+.Show list of current record (listbox widget)
+.Search current entry
+.Add Entry
+.Update Selected
+.Delete Selected
+.Close
+
+Will be using grid method for the GUI.
+
+Future scaling, revisioning:
+Can create another function that clears the entry fields.
+---------------------------------------------------------------------------------------------------------------------------------------------"""
+from tkinter import *
+import backend  # functions
+
+
+# WRAPPER FUNCTIONS THAT CONNECT THE BUTTONS TO THE BACKEND FUNCTIONS...
+
+# this function is called by simply selecting an entry or tuple from the listbox object...its not triggered by a button like the other wrapper functions...
+# list1.bind('<<ListboxSelect>>',get_selected_row)...
+def get_selected_row(event):      # note: the curselection() method returns tuples...
+    try: # prevents IndexError exception from being thrown when user clicks an empty listbox...
+        global selected_tuple # now selected_tuple is a global variable recognized throughout the code...
+        index=list1.curselection()[0] # this trick will grab the first item with index 0 per tuple...otherwise the curselection() output will return tuples like this: (2,) (3,) etc...
+        selected_tuple=list1.get(index) # returns tuple at selected index...                                                                                          # ^ index 0 of this single tuple...
+    #    return selected_tuple
+    #    print(event)
+    #    print(type(event))
+        # the following code will delete or purge the entry fields and will insert(), distribute the selected tuple into the respective entry fields thus displaying it to the user...
+        e1.delete(0,END)
+        e1.insert(END,selected_tuple[1]) # title has an index of [1], the id is the primary key and it has an index of [0]...
+        e2.delete(0,END)
+        e2.insert(END,selected_tuple[2]) # author has an index of [2]
+        e3.delete(0,END)
+        e3.insert(END,selected_tuple[3]) # year has an index of [3]
+        e4.delete(0,END)
+        e4.insert(END,selected_tuple[4]) # isbn has an index of [4]
+    except IndexError:
+        pass
+
+#print(END)
+
+
+# b1 button...text="View All"
+def view_command():
+    list1.delete(0,END) # prevents program from inserting duplicate entries over and over everytime you press View All button...
+    for row in backend.view(): # view() method returns a list of tuples...
+        list1.insert(END,row) # insert list of tuples into listbox object...
+
+# b2=Button(window,text="Search Entry"
+def search_command():
+    list1.delete(0,END)
+    for row in backend.search(title_text.get(),author_text.get(),year_text.get(),isbn_text.get()): # stringVar objects getting strings from user entry...
+        list1.insert(END,row) # insert the  found strings into the listbox object...
+
+# b3=Button(window,text="Add Entry"
+def add_command():
+    backend.insert(title_text.get(),author_text.get(),year_text.get(),isbn_text.get()) # insert new entry into database...
+    list1.delete(0,END) # first clear the list...
+    list1.insert(END,(title_text.get(),author_text.get(),year_text.get(),isbn_text.get())) # then display the new entry to show the user's input...
+    # note the tuple being used so that the new entry display's as a row and not multiple lines...
+
+# b5=Button(window,text="Delete selected"
+def delete_command(): # passing global variable selected_tuple[0]...
+    backend.delete(selected_tuple[0]) # will delete the selected_tuple at index[0] for that single tuple returned...
+    # now you won't get the TypeError: get_selected_row() missing 1 required positional argument: 'event' cuz you are not passing the event arugment to delete_command()...
+
+
+def update_command(): # getting the updated data from the entry fields and updating the database...notice the get() methods...
+    backend.update(selected_tuple[0],title_text.get(),author_text.get(),year_text.get(),isbn_text.get()) # will delete the selected_tuple at index[0] for that single tuple returned...
+    print(selected_tuple[0],selected_tuple[1],selected_tuple[2],selected_tuple[3],selected_tuple[4])
+
+
+
+
+window=Tk()  # all code goes after here...  Tk() not tk() ---> NameError: name 'tk' is not defined
+
+window.wm_title("BookStore App - powered by Python")
+
+
+# label objects and their x y coordinates...
+l0=Label(window,text="Martin Batista Python Prgrmr - Guavadream Media Software")
+l0.grid(row=0,column=0)
+
+l1=Label(window,text="Title")
+l1.grid(row=1,column=0)
+
+l2=Label(window,text="Author")
+l2.grid(row=1,column=2)
+
+l3=Label(window,text="Year")
+l3.grid(row=2,column=0)
+
+l4=Label(window,text="ISBN")
+l4.grid(row=2,column=2)
+
+# entry objects and their x y coordinates...
+title_text=StringVar() # object for user input...
+e1=Entry(window,textvariable=title_text)
+e1.grid(row=1,column=1)
+
+author_text=StringVar() # object for user input...
+e2=Entry(window,textvariable=author_text)
+e2.grid(row=1,column=3)
+
+year_text=StringVar() # object for user input...
+e3=Entry(window,textvariable=year_text)
+e3.grid(row=2,column=1)
+
+isbn_text=StringVar() # object for user input...
+e4=Entry(window,textvariable=isbn_text)
+e4.grid(row=2,column=3)
+
+
+# list box object and its x y coordinates...
+list1=Listbox(window, height=6,width=35)
+list1.grid(row=3,column=0,rowspan=6,columnspan=2)
+
+# scrollnbar object and its x y coordinates...
+sb1=Scrollbar(window)
+sb1.grid(row=3,column=2,rowspan=6)
+
+list1.configure(yscrollcommand=sb1.set)  # tell the list object about the scrollbar object...
+sb1.configure(command=list1.yview) # tell the scrollbar object about the list object...
+
+# associating or binding the wrapper function: get_selected_row to the listbox object...so by selecting an item in the listbox, you call the get_selected_row() functon...
+list1.bind('<<ListboxSelect>>',get_selected_row) # bind() method takes 2 arguments... an event type and a function that you want to bind to the event type...
+
+
+# button objects and their x y coordinates...triggering their associated wrapper functions...
+b1=Button(window,text="View All", width=12, command=view_command) # python would normally run or call this function if passed like this...view_command() with parentheses...
+b1.grid(row=3,column=3)
+
+b2=Button(window,text="Search Entry", width=12, command=search_command)  # this is why we don't use parentheses...Python/tkinter then knows to wait for button to call it...
+b2.grid(row=4,column=3)
+
+b3=Button(window,text="Add Entry", width=12, command=add_command)
+b3.grid(row=5,column=3)
+
+b4=Button(window,text="Update selected", width=12, command=update_command)
+b4.grid(row=6,column=3)
+
+b5=Button(window,text="Delete selected", width=12, command=delete_command)
+b5.grid(row=7,column=3)
+
+b6=Button(window,text="Close", width=12, command=window.destroy) # closes the app...
+b6.grid(row=8,column=3)
+
+window.mainloop()  # all code goes before here...
+
+
+#------------------------------------------------------------------------------** Found Bug **------------------------------------------------------------------------------------
+"""----------------------------------- This occurs when calling the get_selected_row() function by clicking into the listbox object...-------------------------------------------
+DEBUGGING OUTPUT:
+Exception in Tkinter callback
+Traceback (most recent call last):
+  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/tkinter/__init__.py", line 1702, in __call__
+    return self.func(*args)
+  File "frontend.py", line 35, in get_selected_row
+    index=list1.curselection()[0] # this trick will grab the first item with index 0 per tuple...otherwise the curselection() output will return tuples like this: (2,) (3,) etc...
+IndexError: tuple index out of range
+
+must write an IndexError Try block...
+
+** To make an executable file run this ** This creates a single executable file...otherwise you get a bunch of support files that
+are actually good for troubleshooting... include the --onefile parameter...
+pyinstaller --onefile frontend.py
+This command generates a terminal command line in the background of your GUI...to avoid this type in this other parameter called --windowed
+pyinstaller --onefile --windowed frontend.py
+
+
+
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------"""