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Developing Applications Using The SoftwareShield System
>
Creating
Licensing Solutions > Available License Models
> Time Limited Trial License Model
Time Limited Trial License Model
This
model allows you to deliver a time limited trial version of your software
that expires at some arbitrary point in time after the user first runs
the software. When
expired, your software can either stop functioning completely or change
to some other model.
For
detailed information about expiration types and features see Expiring Licenses in the Feature Guide.
Overview - How to Integrate the Time Limited Trial License Model Into
Your Application
The
first step is simply defining a license that expires using an Expire
Period. Note that any of the three types of expiration can be individually
used or used in combination with each other. If used in combination your
application is expired as soon as any one of the types of expiration takes
effect. This section deals with "expire periods". The expire
period is a fixed amount of time that begins to elapse immediately after
your application is run for the first time. After this period is over,
your application is expired. This is the most common type of expiring
license and should be used to create most "trial versions".
The
next step is to ensure that your license has the necessary Authorization
Definitions built into it. You decide which definitions to include based
on how you want your licenses expiration to behave. There are several
Authorization Definitions which can manipulate expiring licenses. You
may need a "Release All Expiration" definition, a "Reset
Expire Period" definition, a "Change Expire Period Duration"
definition, "Composite" definitions (which allow you to use
a combination of definitions simultaneously), or all of them - depending
on what kinds of expiration your build into your license and how you want
it to behave. Please see Authorization Definitions
for detailed information on the Authorization Definition features.
Once
you are satisfied with your license, compile a distributed copy of it.
The distributed copy is encrypted and compressed and only contains absolutely
necessary information for the enforcement of your license. Place a copy
of this distributed license in your applications directory. If you have
decided to use steganographic alias files, make sure that they are also
in the application directory. Have a look at the programming notes file
that the SoftwareShield License Manager creates for your specific license.
This will make your programming a little easier by supplying you with
the code you will need to invoke the start up event. Please see Deploying the License for Your Application
for more detailed information about deploying your license.
Next,
in your programs startup event (main form load etc.) create an instance
of the ClientProtector object (SSCProtector) and immediately call its
StartUp function. You will have to pass specific parameters such as the
license name, main license file password, and the finger print options
code - but this code will have been already written for your convenience
when you compiled your license - just look in the programming notes file
created by the SoftwareShield License Manager. Have a look at the exact
details of the StartUp function for more
information on making this call.
Now,
depending on the return value from the ClientProtector StartUp call (in
the return_code reference parameter), you can determine if the license
is expired or not. If you wish to give the user updated feedback about
how much of his trial period remains, you can make calls to the ClientProtector
to get detailed information about the expiration. See ClientProtector
Reference for more detail. At this point, have your application launch
the program in "trial mode" if it has not yet expired. Shut
down the program if it has expired after prompting the user to buy and
possibly giving them the opportunity to enter an Activation Code if they
already have. Run the program in full release mode if the license has
been unlocked completely. For information on how to interpret the return_code
parameter when deploying a trial version of your application, have a look
at RETURNCODES.
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