/**
* Sencha GXT 3.0.0 - Sencha for GWT
* Copyright(c) 2007-2012, Sencha, Inc.
* licensing@sencha.com
*
* http://www.sencha.com/products/gxt/license/
*/
package com.sencha.gxt.core.rebind;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.TreeLogger.Type;
public class ConditionParser {
private static final Pattern BIN_OPS = Pattern.compile("\\|\\||&&|\\<=|\\>=|\\<|\\>|==|!=|\\+|\\-|\\*|\\/");
private static final Pattern METHOD_PATTERN = Pattern.compile("([a-zA-Z0-9\\._]+\\:[a-zA-Z0-9_]+\\([^\\)]*\\))");
private static final Pattern UNARY_OPS = Pattern.compile("!|" + METHOD_PATTERN.pattern());
private static final Pattern LITERAL = Pattern.compile("[0-9]+|\\\"[^\\\"]*\\\"|\\\'[^\\\']*\\\'|true|false|null");
private static final Pattern WHITESPACE = Pattern.compile("\\s");
private static final Pattern POSSIBLE_STRING_LITERAL = Pattern.compile("\\\'([^\\\']*)\\\'");
private static final Pattern NON_REF = Pattern.compile(WHITESPACE.pattern() + "|" + LITERAL.pattern() + "|"
+ BIN_OPS.pattern() + "|" + UNARY_OPS.pattern());
private TreeLogger log;
public ConditionParser(TreeLogger log) {
this.log = log;
}
public List<Token> parse(String condition) {
TreeLogger l = log.branch(Type.DEBUG, "Parsing condition: " + condition);
// expect lots of whitespace for now... if it doesn't match an expression or
// literal, it must be a ref
List<Token> tokens = new ArrayList<Token>();
Matcher m = NON_REF.matcher(condition);
int lastMatchEnd = 0;
while (m.find()) {
int begin = m.start(), end = m.end();
@SuppressWarnings("unused")
String currentMatch = condition.substring(begin, end);
// look for unmatched sections, indicating refs
if (lastMatchEnd < begin) {
Token ref = new Token();
ref.type = Token.Type.Reference;
ref.contents = condition.substring(lastMatchEnd, begin);
tokens.add(ref);
}
lastMatchEnd = end;
// deal with methods differently than bin/unary ops
Token t = new Token();
Matcher method = METHOD_PATTERN.matcher(m.group());
if (method.matches()) {
t.type = Token.Type.MethodInvocation;
t.contents = method.group(1);
} else {
// TODO consider leaving out whitespace...
t.type = Token.Type.ExpressionLiteral;
t.contents = m.group();
// look for accidental char/string mismatch
Matcher str = POSSIBLE_STRING_LITERAL.matcher(t.contents);
if (str.matches()) {
if (str.group(1).length() > 1) {
t.contents = "\"" + str.group(1) + "\"";
} else {
// TODO mechanism to disable this warn
l.log(
Type.WARN,
"Possible char was turned into a string, please be aware that both ' and \" marks are used for String objects in XTemplates");
}
}
}
tokens.add(t);
}
// look for ending trailing refs
if (lastMatchEnd < condition.length()) {
Token ref = new Token();
ref.type = Token.Type.Reference;
ref.contents = condition.substring(lastMatchEnd);
tokens.add(ref);
}
return tokens;
}
public static class Token {
public enum Type {
Reference, ExpressionLiteral, MethodInvocation
}
public Type type;
public String contents;
}
}