http://code.google.com/p/mybatis/issues/detail?id=356 : added the possibility of skip variables substitution

Author: simotripo

src/main/java/org/apache/ibatis/parsing/GenericTokenParser.java

@@ -37,7 +37,16 @@ public String parse(String text) {
         if (end > start) {
           String before = after.substring(0, start);
           String content = after.substring(start + openToken.length(), end);
-          String substitution = handler.handleToken(content);
+          String substitution;
+
+          // check if variable has to be skipped
+          if (start > 0 && text.charAt(start - 1) == '\\') {
+            before = before.substring(0, before.length() - 1);
+            substitution = new StringBuilder(openToken).append(content).append(closeToken).toString();
+          } else {
+            substitution = handler.handleToken(content);
+          }
+
           builder.append(before);
           builder.append(substitution);
           after = after.substring(end + closeToken.length());

src/test/java/org/apache/ibatis/parsing/GenericTokenParserTest.java

@@ -67,4 +67,12 @@ public void shouldDemonstrateGenericTokenReplacement() {
     assertEquals("Hello } ${ this is a test.", parser.parse("Hello } ${ this is a test."));
   }
 
+  @Test
+  public void shallNotInterpolateSkippedVaiables() {
+    GenericTokenParser parser = new GenericTokenParser("${", "}", new VariableTokenHandler(new HashMap<String, String>()));
+
+    assertEquals("${skipped} variable", parser.parse("\\${skipped} variable"));
+    assertEquals("This is a ${skipped} variable", parser.parse("This is a \\${skipped} variable"));
+  }
+
 }