Function XMLIDEncode

code/AssetLib/Collada/ColladaExporter.cpp:121–147

------------------------------------------------------------------------------------------------ Encodes a string into a valid XML ID using the xsd:ID schema qualifications.

// ------------------------------------------------------------------------------------------------
// Encodes a string into a valid XML ID using the xsd:ID schema qualifications.
static const std::string XMLIDEncode(const std::string &name) {
    const char XML_ID_CHARS[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_-.";
    const unsigned int XML_ID_CHARS_COUNT = sizeof(XML_ID_CHARS) / sizeof(char) - 1;

    if (name.length() == 0) {
        return name;
    }

    std::stringstream idEncoded;

    // xsd:ID must start with letter or underscore
    if (!((name[0] >= 'A' && name[0] <= 'z') || name[0] == '_')) {
        idEncoded << '_';
    }

    for (std::string::const_iterator it = name.begin(); it != name.end(); ++it) {
        // xsd:ID can only contain letters, digits, underscores, hyphens and periods
        if (strchr(XML_ID_CHARS, *it) != nullptr) {
            idEncoded << *it;
        } else {
            // Select placeholder character based on invalid character to reduce ID collisions
            idEncoded << XML_ID_CHARS[(*it) % XML_ID_CHARS_COUNT];
        }
    }

    return idEncoded.str();
}

// ------------------------------------------------------------------------------------------------
// Helper functions to create unique ids