Examples with Expression org.structr.core.parser.Expression used on opensource projects

Example 1 with Expression

use of org.structr.core.parser.Expression in project structr by structr.

the class Functions method evaluate.

public static Object evaluate(final ActionContext actionContext, final GraphObject entity, final String expression) throws FrameworkException, UnlicensedException {
    final String expressionWithoutNewlines = expression.replace('\n', ' ').replace('\r', ' ');
    final StreamTokenizer tokenizer = new StreamTokenizer(new StringReader(expressionWithoutNewlines));
    tokenizer.eolIsSignificant(true);
    tokenizer.ordinaryChar('.');
    tokenizer.wordChars('_', '_');
    tokenizer.wordChars('.', '.');
    tokenizer.wordChars('!', '!');
    Expression root = new RootExpression();
    Expression current = root;
    Expression next = null;
    String lastToken = null;
    int token = 0;
    int level = 0;
    while (token != StreamTokenizer.TT_EOF) {
        token = nextToken(tokenizer);
        switch(token) {
            case StreamTokenizer.TT_EOF:
                break;
            case StreamTokenizer.TT_EOL:
                break;
            case StreamTokenizer.TT_NUMBER:
                if (current == null) {
                    throw new FrameworkException(422, "Invalid expression: mismatched opening bracket before NUMBER");
                }
                next = new ConstantExpression(tokenizer.nval);
                current.add(next);
                lastToken += "NUMBER";
                break;
            case StreamTokenizer.TT_WORD:
                if (current == null) {
                    throw new FrameworkException(422, "Invalid expression: mismatched opening bracket before " + tokenizer.sval);
                }
                next = checkReservedWords(tokenizer.sval);
                Expression previousExpression = current.getPrevious();
                if (tokenizer.sval.startsWith(".") && previousExpression != null && previousExpression instanceof FunctionExpression && next instanceof ValueExpression) {
                    final FunctionExpression previousFunctionExpression = (FunctionExpression) previousExpression;
                    final ValueExpression valueExpression = (ValueExpression) next;
                    current.replacePrevious(new FunctionValueExpression(previousFunctionExpression, valueExpression));
                } else {
                    current.add(next);
                }
                lastToken = tokenizer.sval;
                break;
            case '(':
                if (((current == null || current instanceof RootExpression) && next == null) || current == next) {
                    // an additional bracket without a new function,
                    // this can only be an execution group.
                    next = new GroupExpression();
                    current.add(next);
                }
                current = next;
                lastToken += "(";
                level++;
                break;
            case ')':
                if (current == null) {
                    throw new FrameworkException(422, "Invalid expression: mismatched opening bracket before " + lastToken);
                }
                current = current.getParent();
                if (current == null) {
                    throw new FrameworkException(422, "Invalid expression: mismatched closing bracket after " + lastToken);
                }
                lastToken += ")";
                level--;
                break;
            case '[':
                // bind directly to the previous expression
                next = new ArrayExpression();
                current.add(next);
                current = next;
                lastToken += "[";
                level++;
                break;
            case ']':
                if (current == null) {
                    throw new FrameworkException(422, "Invalid expression: mismatched closing bracket before " + lastToken);
                }
                current = current.getParent();
                if (current == null) {
                    throw new FrameworkException(422, "Invalid expression: mismatched closing bracket after " + lastToken);
                }
                lastToken += "]";
                level--;
                break;
            case ';':
                next = null;
                lastToken += ";";
                break;
            case ',':
                next = current;
                lastToken += ",";
                break;
            default:
                if (current == null) {
                    throw new FrameworkException(422, "Invalid expression: mismatched opening bracket before " + tokenizer.sval);
                }
                current.add(new ConstantExpression(tokenizer.sval));
                lastToken = tokenizer.sval;
        }
    }
    if (level > 0) {
        throw new FrameworkException(422, "Invalid expression: mismatched closing bracket after " + lastToken);
    }
    return root.evaluate(actionContext, entity);
}