Started filtersVisibility extension

src/string.js

@@ -0,0 +1,46 @@
+/**
+ * String utilities
+ */
+
+export default {
+
+    lower(text){
+        return text.toLowerCase();
+    },
+
+    upper(text){
+        return text.toUpperCase();
+    },
+
+    trim(text){
+        if (text.trim){
+            return text.trim();
+        }
+        return text.replace(/^\s*|\s*$/g, '');
+    },
+
+    isEmpty(text){
+        return this.trim(text) === '';
+    },
+
+    rgxEsc(text){
+        function escape(e){
+            let a = new RegExp('\\'+e, 'g');
+            text = text.replace(a, '\\'+e);
+        }
+
+        let chars = ['\\','[','^','$','.','|','?','*','+','(',')'];
+        for(let e=0, len=chars.length; e<len; e++){
+            escape(chars[e]);
+        }
+        return text;
+    },
+
+    matchCase(text, mc){
+        if(!mc){
+            return this.lower(text);
+        }
+        return text;
+    }
+
+};