New OpenLayers.String.format function to Format a string given a string

template and some context -- to be used within the SLD framework. Developed
by Andreas and Sr. Schaub. Thanks, guys!


git-svn-id: http://svn.openlayers.org/trunk/openlayers@5317 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/BaseTypes.js

@@ -87,7 +87,44 @@ OpenLayers.String = {
             camelizedString += s.charAt(0).toUpperCase() + s.substring(1);
         }
         return camelizedString;
+    },
+
+    /**
+     * APIFunction: OpenLayers.String.format
+     * Given a string with tokens in the form ${token}, return a string
+     *     with tokens replaced with properties from the given context
+     *     object.  Represent a literal "${" by doubling it, e.g. "${${".
+     *
+     * Parameters:
+     * template - {String} A string with tokens to be replaced.  A template
+     *     has the form "literal ${token}" where the token will be replaced
+     *     by the value of context["token"].
+     * context - {Object} An optional object with properties corresponding
+     *     to the tokens in the format string.  If no context is sent, the
+     *     window object will be used.
+     *
+     * Returns:
+     * {String} A string with tokens replaced from the context object.
+     */
+    format: function(template, context) {
+        if(!context) {
+            context = window;
+        }
+        var tokens = template.split("${");
+        var item, last;
+        for(var i=1; i<tokens.length; i++) {
+            item = tokens[i];
+            last = item.indexOf("}"); 
+            if(last > 0) { 
+                tokens[i] = context[item.substring(0, last)] +
+                            item.substring(++last); 
+            } else {
+                tokens[i] = "${" + item;
+            }
+        }
+        return tokens.join("");
     }
+
 };
 
 if (!String.prototype.startsWith) {

tests/test_BaseTypes.html

@@ -82,7 +82,41 @@
         t.eq(OpenLayers.String.camelize(str), "chickenHeadMan", "string with multiple middle hyphens and end hyphen is camelized correctly (end hyphen dropped)");
 
 
-   }
+    }
+    
+    function test_String_format(t) {
+        var unchanged = [
+            "", "${ ", "${", " ${", "${${", "${}", "${${}}", " ${ ${",
+            "}", "${${} }"
+        ]
+        t.plan(4 + unchanged.length);
+
+        var format = OpenLayers.String.format;
+        
+        var expected;
+        for(var i=0; i<unchanged.length; ++i) {
+            expected = unchanged[i];
+            t.eq(format(expected), expected,
+                 "'" + expected + "' left unchanged");
+        }
+
+        t.eq(format("${foo} none"),
+             "undefined none", "undefined properties don't bomb");
+
+        window.foo = "bar";
+        t.eq(format("${foo} none"),
+             "bar none", "window context used if none passed");
+        
+        var context = {bar: "foo"};
+        t.eq(format("${bar} foo", context), "foo foo",
+             "properties accessed from context");
+        
+        var context = {bar: "foo", foo: "bar"};
+        t.eq(format("a ${bar} is a ${foo}", context), "a foo is a bar",
+             "multiple properties replaced correctly");
+
+    }
+   
    
     function test_06_Number_limitSigDigs(t) {
         t.plan(9);