Embedding CSS

Embedding CSS in your application is quite easy. All you have to do is create an object from the class KCss. Then you may use member functions to manipulate CSS. When processing is done the KCss object can be deleted.

Have a look at the example below defining and running a CSS function. (You will find a more sophisticated example Embedd.css in theSAMPLES subdirectories):

#include <stdio.h>
#include <strstrea.h>
#include <KCSS.hpp>
 
main()
{
  try {
    IString module("MyTest.exe");
 
    KCss css;                    // create css object
 
    css.loadLibrary("KcSysLib"); // load system library
 
    istrstream str(              // define css function
      "test()"
      "{"
      "  sysLog('hello world');"
      "  return 0;"
      "}"
    );
    css.loadScript(module, &str); // compile the script
 
    IString ret(css.call(module,"test")); // execute test
 
    return ret.asInt();
  }
  catch (IException exc) {
    for (int i=exc.textCount(); i>=0; i--)
      cerr << exc.text(i) << endl;
  }
} // main

Of course you would not hard-code the css function in a real application. You would provide some way for editing the function to the user.

So far this example is of little use, so let's extend the example by an application specific C++ function callable from the script:

#include <stdio.h>
#include <strstrea.h>
#include <KCSS.hpp>
 
/*
 * countDigs: a C++ function callable from CSS
 */
static IString countDigs(KCss* css)
{
  IString str(css->get("string")); // get argument
  char* s(str);        // pointer to string buffer
  int cnt(0);
  while (s) {
    if (*s >= '0' && *s <= '9') cnt++;
    s++;
  }
  return IString(cnt);
} // countDigs
 
main()
{
  try {
    IString module("MyTest.exe");
    KCss css;                    // create css object
 
    css.addFunc(                 // add c++ function
      module,                       // module name
      "countDigs(const string)",    // fct header
      countDigs);                   // fct address
 
    istrstream str(              // define css function
      "test2()"
      "{"
      "  return countDigs('+41 (81) 322 83 84');"
      "}"
    );
    css.loadScript(module, &str); // compile the script
 
    IString cnt(css.call(module,"test2")); // call test2
 
    cout << "count = " << cnt << endl; // will show: count = 11
    return 0;
  } // try
  catch (IException exc) {
    for (int i=exc.textCount(); i>=0; i--)
      cerr << exc.text(i) << endl;
  } // catch
} // main

Instead of loading the script from memory as in the examples above you could also load the script from a file of course:

  ...
  css.loadScript("User.css");
  ...

For test purpose you may also call your function without a CSS script envolved:

  ...
  IString cnt = css.call(module,"countDigs",1,"++123-456-778899");
  ...