Translate js snippet to MVC flavor

Author: gyoshev

aspnet-mvc/helpers/editor/how-to/add-max-length-validation.md

@@ -0,0 +1,53 @@
+---
+title: Add max-length validation
+page_title: Add max-length validation
+description: Add max-length validation
+---
+
+# Add max-length validation
+
+The snippet below demonstrates how to define custom kendo validators to check the length of the text content, or the length of the HTML content, via custom validation rules.
+
+#### Example
+
+    <form>
+        @(Html.Kendo().Editor()
+              .Name("editor")
+              .HtmlAttributes(new { data_maxtextlength="50", data_maxtextlength_msg="Text must be shorter than 50 chars" })
+              .Value("Lorem ipsum dolor sit amet. Lorem ipsum dolor sit.")
+        )
+
+        <button class="k-button k-primary">Submit</button>
+    </form>
+
+    <script>
+
+        // register custom validation rules
+        (function ($, kendo) {
+            $.extend(true, kendo.ui.validator, {
+                rules: {
+                    maxTextLength: function (textarea) {
+                        if (textarea.is("[data-maxtextlength-msg]") && textarea.val() != "") {
+                            var maxlength = textarea.attr("data-maxtextlength");
+                            var value = textarea.data("kendoEditor").value();
+                            return value.replace(/<[^>]+>/g, "").length <= maxlength;
+                        }
+
+                        return true;
+                    },
+                    maxHtmlLength: function (textarea) {
+                        if (textarea.is("[data-maxhtmllength-msg]") && textarea.val() != "") {
+                            var maxlength = textarea.attr("data-maxhtmllength");
+                            var value = textarea.data("kendoEditor").value();
+                            return value.length <= maxlength;
+                        }
+
+                        return true;
+                    }
+                }
+            });
+
+            $("form").kendoValidator();
+        })(jQuery, kendo);
+    </script>
+