std::string &varSubst(std::string &aStr, char varId, const IVarSubstCallback *cb, const char *stdPath, const char *curPath)
{
/**
* Rib variables (RiSPEC draft) are written like $var $table:var ${table:var} (however,
* in RiSPEC variables in 'if expressions' are also given as $(calcvar) - these calculated variables are not evaluated
* here).
*
* Expansion only if Option "rib" "string varsubst" is set to a character (e.g. "$"). Will need some changes
* in future, also some in CStringList (remove the substitution). Maybe - also move the expansion of the variable
* from parsing to the backend, to allow the C++ binding to use variables - that will be more difficult
* to implement of course. Problem: in an if expression in an Archive the variable $Frame occurs. $Frame is substituted
* with the current frame number - being different to the number of the time of instanciation (leads also to errors in
* cached file archives). However, e.g. $Frame and ${Frame} is expanded while parsing, $(Frame) in if expressions while
* instanciating. Maybe will add a control to disable the evaluation of variables for the ribwriter.
* @see getValue() CStringList
*/
// No substitution?
if ( !varId && !stdPath && !curPath )
return aStr;
bool found = false;
std::string result, resval;
std::string varname;
CValue p;
std::string::const_iterator i = aStr.begin();
while ( i != aStr.end() ) {
if ( (*i) == '@' && stdPath ) {
found = true;
p.get(resval);
result += stdPath;
++i;
continue;
}
if ( (*i) == '&' && curPath ) {
found = true;
result += curPath;
++i;
continue;
}
if ( varId && (*i) == varId ) {
++i;
if ( i != aStr.end() ) {
varname = "";
p.clear();
if ( (*i) == '{' ) {
++i;
int depth = 0;
for ( ; i != aStr.end() && !((*i) == '}' && !depth); ++i ) {
if ((*i) == '{')
++depth;
if ((*i) == '}')
--depth;
varname += (*i);
}
if ( i != aStr.end() )
++i;
varSubst(varname, varId, cb, stdPath, curPath); // recursive e.g. ${$var1$var2};
if ( (cb && cb->getValue(p, varname.c_str())) || getEnvValue(p, varname.c_str()) ) {
found = true;
p.get(resval);
result += resval;
} else {
result += "${";
result += varname;
result += "}";
}
} else {
for ( ; i != aStr.end() && (isalnum(*i) || (*i) == ':'); ++i ) {
char c = (*i);
if ( c == ':' ) {
++i;
if ( (*i) == varId ) {
--i;
break;
}
--i;
}
varname += c;
}
// No i++
if ( (cb && cb->getValue(p, varname.c_str())) || getEnvValue(p, varname.c_str()) ) {
found = true;
p.get(resval);
result += resval;
} else {
result += "$";
result += varname;
}
}
}
} else {
result += (*i);
++i;
}
}
if ( found )
aStr = result;
return aStr;
}
