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request_and_response.htm
Navigation:  Templates > Guide to all Templates > General Topics >====== Clarion templates - Request and Response ====== Previous pageReturn to chapter overviewNext page

Clarion ships with two distinct Template sets, the original “Clarion” templates, and the “ABC” Templates. The “Clarion set of templates generates a very easy to read and use Procedural application. The “ABC” set of templates (also very easy to use) generates a class based application, hence the name ABC is short for “Application Builder Classes”.

The “Clarion templates” use a Request and Response system. This system maintains the integrity of inter-procedure communications.

There are three components to the Request and Response system:

Global Variables: GlobalRequest and GlobalResponse. In GENERATED code, there are no points between the place that either variable is assigned a value and the place the value is interpreted. These variables are defined as:GlobalRequest      LONG,THREADGlobalResponse   LONG,THREAD

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If you are creating an application that consists of more than one generated DLL, you must check the “Generate Internal Global Data as EXTERNAL” check box for all DLLs except one. Likewise, you must check the “Generate Internal Global Data as EXTERNAL” check box for each APP creating an .EXE.

Local Variables: ThisWindow.Request (or SELF.Request), ThisWindow.Response (or SELF.Response), ThisWindow.OriginalRequest (or SELF.OriginalRequest).
ThisWindow.Request (or SELF.Request) and ThisWindow.OriginalRequest (or SELF.OriginalRequest) are assigned value immediately after the procedure begins.
ThisWindow.Response (or SELF.Response) is assigned a value before a bit of code signals the exit of the procedure. Right before the procedure terminates, GlobalResponse is assigned the value of ThisWindow.Response (or SELF.Response).
Enumerated EQUATEs: These are primarily to increase readability of the code. The actual numbers themselves are inconsequential, with one exception; Request values less than 0 are reserved for use in multi-page systems.
InsertRecord EQUATE (1) ! Add a record to table
ChangeRecord EQUATE (2) ! Change the current record
DeleteRecord EQUATE (3) ! Delete the current record
SelectRecord EQUATE (4) ! Select the current record
ProcessRecord EQUATE (5) ! Process the current record
ViewRecord EQUATE (6) ! View the current record
SaveRecord EQUATE (7) ! Save the current record
RequestCompleted EQUATE (1) ! Update Completed
RequestCancelled EQUATE (2) ! Update Aborted
request_and_response.htm.txt · Last modified: 2021/04/15 15:57 (external edit)