add t.js template engine

Author: glaszig

app/assets/javascripts/t.js

@@ -0,0 +1,103 @@
+/*
+     _     _
+    | |   (_)
+    | |_   _ ___
+    | __| | / __|
+    | |_ _| \__ \
+     \__(_) |___/
+         _/ |
+        |__/
+
+  t.js
+  a micro-templating framework in ~400 bytes gzipped
+
+  @author  Jason Mooberry <[email protected]>
+  @license MIT
+  @version 0.1.0
+
+*/
+(function() {
+
+  var blockregex = /\{\{(([@!]?)(.+?))\}\}(([\s\S]+?)(\{\{:\1\}\}([\s\S]+?))?)\{\{\/\1\}\}/g,
+    valregex = /\{\{([=%])(.+?)\}\}/g;
+
+  function t(template) {
+    this.t = template;
+  }
+
+  function scrub(val) {
+    return new Option(val).innerHTML.replace(/"/g,"&quot;");
+  }
+
+  function get_value(vars, key) {
+    var parts = key.split('.');
+    while (parts.length) {
+      if (!(parts[0] in vars)) {
+        return false;
+      }
+      vars = vars[parts.shift()];
+    }
+    return vars;
+  }
+
+  function render(fragment, vars) {
+    return fragment
+      .replace(blockregex, function(_, __, meta, key, inner, if_true, has_else, if_false) {
+
+        var val = get_value(vars,key), temp = "", i;
+
+        if (!val) {
+
+          // handle if not
+          if (meta == '!') {
+            return render(inner, vars);
+          }
+          // check for else
+          if (has_else) {
+            return render(if_false, vars);
+          }
+
+          return "";
+        }
+
+        // regular if
+        if (!meta) {
+          return render(if_true, vars);
+        }
+
+        // process array/obj iteration
+        if (meta == '@') {
+          // store any previous vars
+          // reuse existing vars
+          _ = vars._key;
+          __ = vars._val;
+          for (i in val) {
+            if (val.hasOwnProperty(i)) {
+              vars._key = i;
+              vars._val = val[i];
+              temp += render(inner, vars);
+            }
+          }
+          vars._key = _;
+          vars._val = __;
+          return temp;
+        }
+
+      })
+      .replace(valregex, function(_, meta, key) {
+        var val = get_value(vars,key);
+
+        if (val || val === 0) {
+          return meta == '%' ? scrub(val) : val;
+        }
+        return "";
+      });
+  }
+
+  t.prototype.render = function (vars) {
+    return render(this.t, vars);
+  };
+
+  window.t = t;
+
+})();