

TParadoxDSNCreator
Paradox DSN
Creation Component
Most
recent updates to this and other files can be found at: http://www.gwacc.com/software.htm
What is it?
This component is used to Add, Reconfigure and Remove
Paradox Datasource Names (DSNs) on the fly. Usually this
is done via the ODBC32 control panel applet in any standard windows
installation.
Why use it?
Ever needed to create a Paradox Datasource Name (DSN)
on the fly from inside your Delphi code? We certainly have! This incredibly
useful little Delphi component allows you to create, modify and delete DSNs
at runtime from a Delphi application (32 bit only).
Why would you want
to do this? Quite often we (as developers at GWAcc) find ourselves
having to climb into the control panel and muck around inside the ODBC32
applet. It gets annoying, especially if you have to do it several times
in a row, even more so when it means having to switch between changing user
names, passwords, paths, exclusivity... you get the idea!
This control allows
you to add or change all the properties of a Paradox
DSN, in a single movement.
Simply set
a couple of properties, add ONE line of code to your application, and you
can Add, Reconfigure and Remove Paradox DSNs in a flash!
An example application
has been included with the component, that you can use to check the assignment
of properties and invocation of methods.
Properties
About :
Displays an 'About' box, with your registered status and our contact details
Action : TDSNExecuteAction
The action to perform when the Execute method is invoked. The action can
consist of the following values:
DSNNameOrAlias
: String
The name for the DSN as it will appear in the drop down list of aliases
available to the development environment. This is the internal name used
by the ODBC drivers. No spaces to occur in this string. The component will
accept them, but then if you try to modify the DSN via the control panel,
it might get upset with you. Example: "TstDSN"
DSNUserDescription
: String
The name that you will refer to it by, kind of like a comment string.
After all "My Test DSN" is a lot more meaningful than "TstDSN".
DatabaseDir :
String
The fully qualified path to an existing directory of Paradox database
file(s) (if it exists). The Filename itself is given by the Table Object.
The DSN only points to the DIRECTORY, not a database file (for example,
as in the case of MS Access Databases). The control does NOT check to see
if the Directory already exists, since you may want to create the directory
and the database on the fly as well, either prior to or subsequent to using
this control.
If you already have a directory
set up with the database files in it, you can use the Object Inspector to
locate these files. Note that only the path name is stored
in the component.
Example "c:\testapplication\"
UserID : String
Some Paradox databases require a login and a password to be able to open
them. This is the login name.
Example: "JoeSoap"
In the case of the Paradox DSNs, UserID appears to have no effect
on actually granting access to the tables when they're opened. It has been
left in as a property to cover future possible expansion
NetFilePath
: String
Some Paradox databases require a workgroup file used to control user table
locking and so on. This property allows you to set the path to this. Again,
the control will NOT check to see if this file exists first, since this
may also need to be created on the fly.
Example "c:\pdoxusrs.net"
Password : String
Some Paradox databases require a login and a password to be able to open
them. This is the password that must be supplied if necessary
Example: "TestPass"
In the case of the Paradox DSNs, Password appears to have no effect
on actually granting access to the tables when they're opened. It has been
left in as a property to cover future possible expansion
The
following extended options are directly applicable to the DSN type and affect
how the ODBC32 drivers will handle your databases. You can check these values
by opening control panel, running the ODBC32 applet, double clicking any
Paradox DSN and looking under the advanced options for it.
optCollateSequence
: TCollatingSequence (ASCII,
International, Norwegian-Danish, Swedish-Finnish)
optExclusive
: Boolean
optImplitCommitSync
: String (Yes/No)
optNetVersion
: TNetVersion (NetVersion3x, NetVersion4x, NetVersion5x)
optParadoxVersion
: TParadoxVersion (Paradox3x, Paradox4x, Paradox5x)
optPageTimeout
: Longint
optDSNReadOnly
: Boolean
optSafeTransactions
: Longint
optThreads : Longint
optUserCommitSync : Boolean
In the case of the Paradox DSNs, optDSNReadOnly, optSafeTransactions,
optThreads and optUserCommitSync appear to have no effect. They have been
left in as properties to cover future possible expansion
The full list of the Enumerated Constants (TNetVersion,
TParadoxVersion, TCollatingSequence) can be picked up from the relevant
property in the Object Inspector.
back
to top...
Methods:
This component only has one method.
Execute : Boolean
This method triggers the action you defined by the Action property above.
Some of the properties may not actually need to be used, for example
with the REMOVE_DSN action, only the DSNNameOrAlias needs to
be supplied. The action is synchronous, and the function will return
only after it has attempted the action you requested.
Returns: True = Your action succeeded, False = Your action failed (for
example trying to remove a nonexistent DSN).
Note:
For unregistered users, if the DSN already exists, it will return 'False'
and the DSN will not be updated. It will only return true and create
the DSN if it did not already exist. Unregistered users will need to
delete the DSN via the control panel ODBC32 applet before it can be
recreated. This is not an issue for registered users or for those who
have bought the source code.
Events
This component triggers no events
back
to top...
Installation
First, if you have
any older or shareware versions of this library, remove all references
to these first, this includes removing the package ParadoxDSN_Dx.bpl
from your installed packages list. Also check that the path to any
of the units has been removed from your library path.
Unzip
the package you downloaded.
In Delphi, go to "Components" | "Install Packages" menu
item, click on the "Add" button and select ParadoxDSN_Dxx.bpl
file from the list.
A new page will appear on the component palette (GWACC) with the
component(s) on it. In order to compile and run the included example application,
as well as any other application you create using this component, you will
also need to add the path to the .dcu files to your environment search path.
To do this in Delphi,
first locate the file it's looking for (for example c:\pdoxdsn\paradoxdsncreateunit.dcu),
and then by going to "Tools" | "Environment Options"
| "Library" and adding the path to the "Library Path"
settings. If you don't add the path to the Delphi Library Search Path, you'll
get an error when compiling an application that the compiler can not find
'ParadoxDSNCreateUnit.pas' or 'ParadoxDSNCreateUnit.dcu'.
If you bought
the source for the software, simply go to "File" | "Open"
in Delphi and select the "ParadoxDSN_DX.dpk" package. This
was designed for Delphi 4, but will work fine in Delphi 5 and should
work for other versions such as Delphi 6, and Borland C++Builder too.
In this case it will ask you if you want to upgrade the package to the
new format. Answer "Yes", and then click on the "Compile"
button. After this is complete, click on the the "Install"
button to install the component on the GWACC page (default) or on the
page you selected. See above about adding the path to the units to the
Delphi library search path if you get any errors during compilation.
Installation
- Delphi 6 Users - File Not Found - DsgnIntf.dcu/Proxies.dcu
A
number of Delphi 6 users have reported a problem with the compilation
of the source code, reporting units not found and other errors. The
steps below should remedy the problem:
-
When
you compile, you may get a compile error: File not found: 'DesignIntf.dcu'
-
Open
Tools > Environment options > Library, and add a path to ToolsAPI,
like this: $(DELPHI)\Source\ToolsAPI
-
After
adding that file, if the compile stops in DesignEditors at:
uses DesignConst, Consts, RTLConsts, Contnrs, Proxies; File not
found: 'Proxies.dcu'.
-
In DesignEditors.pas, comment 'Proxies' out, like this:
uses DesignConst, Consts, RTLConsts, Contnrs;//, Proxies;
-
In DesignEditors, locate:
function CustomModule.ValidateComponentClass(ComponentClass:
TComponentClass):
and comment out the code line:
while IsProxyClass(ComponentClass) do ComponentClass := TComponentClass(ComponentClass.ClassParent);
-
In
the 'pdsncompreg.pas' file, replace the 'DsgnIntf' in the
'uses' clause at the top, with 'DesignIntf'
-
In
the 'ParadoxDSNCreateUnit.pas' file, replace 'DsgnIntf'
in the uses clause with 'DesignIntf, DesignEditors'.
-
Recompile,
and your problems should be solved
If you downloaded
the shareware trial release, the file will be called ParadoxDSN_DxU.bpl
where 'x' corresponds to the delphi version you are using. The registered
version will simply be named ParadoxDSN_Dx.bpl. You will also
need to add the path to the .dcu files to your environment search path.
Do this in Delphi by going to "Tools" | "Environment
Options" | "Library" and adding the path to the "Library
Path" settings.
History of changes
November 1, 2001. 1.0.0.2 First public release.
Future plans:
Apart from any possible bug fixes, there are no major changes planned for
this component
Known bugs
There are no known bugs at this time. If you find some bugs, please report
them to gwacc@kagi.com. The support
email address gwacc@kagi.com is available
for all your comments, questions and ideas. If you'd like to see some additional
functionality in this component, please let us know!
Benefits of registration
By registering one or more licenses, you have the right to incorporate this
component into as many applications as you like, royalty-free. If you decide
to purchase the license for this, or any other GWAcc component, you will
get one year of free upgrades. New versions of components will be available
to you at significantly lower price after the period of one year (during
which you get all new versions for free).
How to register
Visit http://www.gwacc.com/software.htm
and register online. All major credit cards apply through secure Internet
protocol. You can also register via fax, international mail order, bank
wire or US Check.
License :
Please read carefully the EULA_license.txt file before using this software.
In addition
to this, GWAcc grants you the license to distribute the shareware
version ONLY of this component, however you see fit, as long as ALL
the files are kept together in one archive. We will not levy any charges
for your distributing of the shareware components in any format, electronic
or otherwise.
You may
NOT redistribute the registered versions of this software to anyone, except
with the express, written permission of GWAcc Limited.
back
to top...