6 Host application development

TEAL compiler can produce compiled templates not only for DbUML application, but for any other application needed in text generation. To be able to use TEAL templates, application has to implement Data Processor interface, load template library and call desired template function. TEAL compiler comes with a demo project "FileSysReport" to generate a text representation of a file system structure. The project includes an application source code and an example templates. A compiled application and templates are also available.

6.1 Generator interface

Generator DLL created as result of TEAL template file compilation contains following exported functions

void Init(int). After loading of DLL into memory the host process has to call this function to initialize the generation

process. The parameter is reserved for future versions.

void Finit(). Before DLL unloading, the host application has to call this function to release all resources allocated by

DLL code.

void RegProcessorCall(int, void*). The function is used to register call-back functionality of Data Processor implemented

by host application. For details look "Data Processor interface and implementation" below.

void* AllocDllMem(int). This function can be used to allocate a memory block using internal DLL mechanism. Usually this

function is never used by host application - all internal memory alocations are done inside of DLL code.

void FreeDllMem(void*). All textual results generated by DLL reside in a memory allocated by DLL code. After result is

used by the host application, the memory has to be released to avoid memory leak. Use this function to release memory allocated

by generation functions implemented in DLL.

char* GetResource(char*). The function returns a text associated with parameter using TEAL "resource" command. The result

has to be released using FreeDllMem function.

char* __<exported template function name>(<parameters>). For each exported TEAL function compiler generates a DLL function

prefixed with double underscore. The full comma-delimited list of such functions is available via GetResource("export") call -

each function name in the result are followed by colon-separated list of parameter types enclosed in parenthesis. For example

__main(p),__main2(p:p),__genprm(p:s)

where "p" means "pointer to an object" and "s" means "string". Results of exported template functions have to be released by

FreeDllMem calls.

[TBD]

6.2 Data Processor interface and implementation

TCountFunc = function(obj: TObject): integer; cdecl;

TGetFunc = function (obj: TObject; index: integer): TObject; cdecl;

RIterator = record

count: TCountFunc;

get: TGetFunc;

end;

PIterator = ^RIterator;

procedure GetIterator(obj: TObject; const code: pchar; var pitr: PIterator); cdecl;

function GetProperties(obj: TObject; const name: pchar; container: TObject): pchar; cdecl; // obsolete ?

procedure SetEnv(const name, value: pchar); cdecl;

function GetEnv(const name: pchar): pchar; cdecl; // not used

function GetObjAttrs(obj: TObject; container: TObject): cardinal; cdecl; // obsolete

procedure SetObjAttrs(obj: TObject; container: TObject; value: cardinal); cdecl; // obsolete

function RunFun(const name: pchar; params: Ppointer; count: integer): pchar; cdecl;

[TBD]