Put Final Touches on an Application

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Dwayne Shaw
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Put Final Touches on an Application Callahan Chapter 11 Preparing Your Application for Distribution Controlling How Your Application Starts Forms-based bound forms for data presentation dialog boxes

1 Put Final Touches on an Application Callahan Chapter 11 Preparing Your Application for Distribution Controlling How Your Application Starts Forms-based bound forms for data presentation dialog boxes Switchboard for inter-form navigation Ensure errors are handled every VB procedure has an On Error statement to enable error handling Error event is handled for each form/report Designate a startup form typically a Switchboard or a frequently used data entry form Customize the application s startup appearance hide Navigation Pane, Title Bar caption, customized Ribbon Test, test, test! Custom Ribbon menus Custom Help, ToolTips, Status Bar Prepare application for network use and maintenance split file architecture Security options encrypt and password protect deploy multiple front-ends deploy front-end as an ACCDE/MDE Handle multi-user issues coming soon 1

2 Providing a StartUp Form for Your Application Switchboard form purpose? contents? Add a command button to exit the application needed to tweak Wizard s code since the Switchboard has no RecordSource (unbound) the Dirty property not available Private Sub QuitApplication_Click() On Error GoTo Err_QuitApplication_Click 'If Me.Dirty Then Me.Dirty = False 'delete to prevent an error DoCmd.Quit Exit_QuitApplication_Click: Exit Sub Err_QuitApplication_Click: MsgBox Err.Description Resume Exit_QuitApplication_Click End Sub Providing a StartUp Form for Your Application Changed several form-level properties Caption AllowDatasheetView ScrollBars RecordSelectors NavigationButtons AutoCenter BorderStyle 2

Make Your Switchboard Form Open Automatically StartUp Options actions that take place automatically when the database is opened File Options Current Database each can also be set using VBA code can

caption for Access window s title bar Display Form designate which form to open as application loads Display Navigation Pane cleared this so Navigation Pane would be hidden why hide Navigation Pane?

3 Make Your Switchboard Form Open Automatically StartUp Options actions that take place automatically when the database is opened File Options Current Database each can also be set using VBA code can bypass by holding [Shift] as DB opens can create a custom database property called AllowByPassKey to take away this capability Startup Options used in Callahan 11 Application Title designate a caption for Access window s title bar Display Form designate which form to open as application loads Display Navigation Pane cleared this so Navigation Pane would be hidden why hide Navigation Pane? Practice Time Use Startup Options in Artie s List.mdb to provide an application title of Artie Enterprises, Inc. disallow special Access keys disable Layout View disable Design Changes display the Navigation Pane we don t have a Switchboard form yet designate frmrestaurant as the initial form to be displayed do not allow full menus disable shortcut menus Test your startup options close and reopen Artie s List.mdb test/confirm each startup option above close and reopen Artie s List.mdb while holding [Shift] key to test bypass 3

query, the query definition, report definition, and entire table of data come down network to workstation where ACE/Jet runs the query, applies criteria, passes results to Access to format as

4 File Server Approach (review from Balter 1) Supports multiple concurrent users.accdb/.mdb file stored in a shared network folder All processing is done on user s workstation, where Access & ACE/Jet run eg: open an MDB file in a shared folder; run a report whose record source is a query, the query definition, report definition, and entire table of data come down network to workstation where ACE/Jet runs the query, applies criteria, passes results to Access to format as specified by report s definition a performance bottleneck! Lots of network traffic especially problematic when lots of users File Server Approach: Enhancement Subscription Data.mdb Subscription.mdb Split file Architecture back-end database file has data tables place it in a shared folder on the network one shared set of tables that multiple users can access front-end database file (aka the application database) has queries, forms, reports, macros, modules, static tables, links to production tables can have links to multiple back-ends deploy a copy on each user s workstation performance is enhanced only tables travel the network eg: open a local application database MDB/ACCDB file, run a report whose record source is a query, the query definition, and report definition are already local table links are used to connect to back-end file, entire table of data comes down network to workstation where ACE/Jet runs the query, applies criteria, passes results to Access to format as specified by report s definition 4

Split the Subscription Database into Two Files Advantages data is sharable via the network back-end is the common data source reduces network load since front-end object definitions are local

5 Split the Subscription Database into Two Files Advantages data is sharable via the network back-end is the common data source reduces network load since front-end object definitions are local improved performance: since queries, forms, reports, macros, modules are stored locally, there is less network traffic. system is more responsive only the data tables travel over the network application maintenance is independent of the data developer can modify the application front-end without disturbing the existing application and data Disadvantages when rename/move/delete the back-end file, the front-end won t be able to access any data! alternative fixes coming up linked tables lack some functionality can't: use Table-type recordsets, Seek method, modify linked table s structure Database Splitter Exports tables to a new back-end file, then sets up links so back-end tables can be accessed by objects in the front-end (application) database Database Tools Move Data group Access Database Practice Time exit Access and backup your Artie s List-yourname.mdb by copying it rename the copy as Artie s List-yourname (BEFORE DB SPLITTER).mdb write-protect Artie s List-yourname (BEFORE DB SPLITTER).mdb open Artie s List-yourname.mdb and use the Database Splitter create the back end in your \CIS217 Data Files\Others folder and name the back-end file Artie s List yourname DATA.mdb notice the link icons for tables in the front-end ToolTip reveals path in back-end 5

Checking and Fixing Linked Tables When rename/move/delete the back-end file, the frontend won t be able to access any data until the links are updated demo Three ways to fix broken table links delete

6 Checking and Fixing Linked Tables When rename/move/delete the back-end file, the frontend won t be able to access any data until the links are updated demo Three ways to fix broken table links delete each linked table, then External Data > Access > Link use Linked Table Manager to re-establish links right-click a linked table Linked Table Manager or Database Tools Linked Table Manager demo use VBA to have user point to back-end file, then rebuild the table links Callahan s CheckLinks() function Add Code to Check and Fix Linked Tables Use VBA to have user point to back-end, then rebuild table links Public Function CheckLinks() As Boolean ' Check linked tables relink if necessary. Returns true if ' links are okay (or links are successfully refreshed). On Error GoTo CheckLinksErr Dim tdf As TableDef Dim strnewmdb As String Dim fd As FileDialog ' Loop through each table in the current database. ' Loop through each table in the current database. For Each tdf In CurrentDb.TableDefs ' Check whether this table is linked (connect string not blank) ' and whether its link is broken (no fields in the Fields collection) If Len(tdf.Connect) > 0 And tdf.fields.count = 0 Then ' If we don't have an MDB name yet, display a message and ' then ask the user to pick a new file. If Len(strNewMDB) = 0 Then MsgBox "The back-end data file for this database has been 6

Add Code to Check and Fix Linked Tables Two main ways to run code when an application starts designate a startup form and use its events to trigger code have the startup form s Load or Open event

7 Add Code to Check and Fix Linked Tables Two main ways to run code when an application starts designate a startup form and use its events to trigger code have the startup form s Load or Open event call a VBA procedure Callahan added code to Switchboard form s Load event AutoExec macro if present, runs automatically after any Startup options are processsed can use RunCode macro action to run a VBA function Artie s List has a hidden AutoExec macro that calls a function named DBStartUp demo Practice Time Modify Artie s List front-end to check for & fix broken table links unhide AutoExec macro and bastrackactivity module import Subscription.mdb s Relinker module into Artie s List.mdb modify DBStartup to call the CheckLinks function Debug > Compile Artie s List error need a reference to use FileDialog object Tools > References > Microsoft Office 12.0 Object Library Debug > Compile Artie s List (ok now) Test exit Access rename Artie s List DATA.mdb to Artie s List DATAzzz.mdb re-open the front-end to see CheckLinks in action rename Artie s List DATAzzz.mdb to Artie s List DATA.mdb re-open the front-end to see CheckLinks in action 7

Protecting Your Application with a Password Encryption scrambles MDB/ACCDB file so it is unreadable outside of Access Password

front-ends To encrypt and password protect 1. File Open Open Exclusive 2.

mdb exclusively, set password 45timexmeDia3 Open Exclusive while hold [Shift] Practice Time Test that you can open the

mdb 45timexmeDia3 the file did open but it couldn t link to the password-protected backend! close Artie s List.

8 Protecting Your Application with a Password Encryption scrambles MDB/ACCDB file so it is unreadable outside of Access Password controls access to database & contents anyone who knows the password has access to its objects consider deploying multiple front-ends To encrypt and password protect 1. File Open Open Exclusive 2. File Set Database Password Practice Time open Artie s List DATA.mdb exclusively, set password yellowgm5474%j open Artie s List.mdb exclusively, set password 45timexmeDia3 Open Exclusive while hold [Shift] Practice Time Test that you can open the password-protected backend Artie s List DATA.mdb yellowgm5474%j success close the backend open the master front-end Artie s List.mdb 45timexmeDia3 the file did open but it couldn t link to the password-protected backend! close Artie s List.mdb, remain in Access re-open Artie s List.mdb 45timexmeDia3 while hold [Shift] add new constant to Relinker module modify CheckLinks to use the backend password open the master front-end Artie s List.mdb 45timexmeDia3 8

9 Deploying an MDE/ACCDE Concepts an Access file format that protects form, report, and module objects deploy front-ends as MDE/ACCDE the following tasks are prohibited in an MDE/ACCDE file view/modify VBA code modules create/modify forms, reports, or modules can create/modify tables, queries, macros import/export forms, reports, or modules can import/export tables, queries, macros Database Tools Make MDE compiles all VBA modules, removes source code, compacts destination file the original MDB/ACCDB file remains unmodified the original mdb/accdb is the master for future development! when you need to modify form, report, or module, do so in the the original MDB/ACCDB file, then make a new MDE/ACCDE file Practice Time with Artie s List.mdb (front-end) open, make MDE in \CIS217 Data Files\Others folder exit Access, open Artie s List.mde close the file, reopen Artie s List.mde with [SHIFT] and attempt each prohibited task Deployment & Beyond Copy the back-end database to a shared folder on the server users need permissions to create, read, & modify files in that folder Copy the front-end mde/accde file to each user s workstation linked tables local Q/F/R/M/M Backup the front-end mdb/accdb the file for future development Backup the back-end! periodically on a specified schedule off-site storage Compact the back-end for database health and performance Fixes, Enhancements, & New Features make changes in master MDB new Q/F/R/M/M modify objects in master MDB make new mde/accde & deploy 9

Find and Filter Records on a Form

Find and Filter Records on a Form Callahan Chapter 3 All About Me Review each form/report can have its own module Me a reference to the form/report whose code is currently executing eg: Me.AllowEdits =