Hi David,

Thanks for your information. Which Forms version are you using ? Can you provide us the code of custom datetime element  so that we can investigate ?

Hi Quan,

I'm using version 4.10.0

I've modified my code to work in .cshtml file rather an .ashx file, the logic should all be exactly the same however..

@using EPiServer.Forms.Helpers.Internal  
@using EPiServer.Forms.Samples.EditView
@model EpiServer.Models.Blocks.Forms.DipsDateTimeElementBlock

    @{
      var formElement = Model.FormElement;
      var labelText = Model.Label;
      var errorMessage = Model.GetErrorMessage();
    }

<div class="Form__Element Form__CustomElement FormDateTime @Model.GetValidationCssClasses()" data-epiforms-element-name="@formElement.ElementName">
<label for="@formElement.Guid" class="Form__Element__Caption">@labelText</label>
<input name="@formElement.ElementName" id="@formElement.Guid" type="text" class="Form__CustomInput FormDateTime__Input"
       placeholder="@Model.PlaceHolder" value="@Model.GetDefaultValue()" @Model.AttributesString />

<span data-epiforms-linked-name="@formElement.ElementName" class="Form__Element__ValidationError" style="@(string.IsNullOrEmpty(errorMessage) ? "display:none" : "" )">@errorMessage</span>
 
  @if (!EPiServer.Editor.PageEditing.PageIsInEditMode)
  {
  // push this Element information to a global blob. Then Samples.js will init them all at once.
    var pickerType = ((DateTimePickerType) Model.PickerType).ToString().ToLower();

    <script type="text/javascript">
       var __SamplesDateTimeElements = __SamplesDateTimeElements || [];
       __SamplesDateTimeElements.push({
         guid: "@formElement.Guid",
         pickerType: "@pickerType"
       });
     </script>
  }
</div>

Can provide the C# code of the block itself if need be, simply inherits from the DateTimeElementBlock and has an extra property as mentioned..

Hi David, 

Yes please provide all extra properties. I'm trying to reproduce the error now and will be back here soon.

namespace Redweb.EpiServer.Models.Blocks.Forms
{
    using System.ComponentModel.DataAnnotations;
    using Attributes;
    using EditorProperties;
    using Enumerations;
    using EPiServer.Core;
    using EPiServer.DataAbstraction;
    using EPiServer.DataAnnotations;
    using EPiServer.Forms.Samples.Implementation.Elements;
    using EPiServer.Shell.ObjectEditing;

    /// <summary>
    /// The DIPS DateTime form element block.
    /// </summary>
    /// <seealso cref="EPiServer.Forms.Samples.Implementation.Elements.DateTimeElementBlock" />
    [ContentType(
        DisplayName = "DIPS Date Time",
        GUID = "{13D43BE2-05B5-4972-ABEE-70F2A815777E}",
        Description = "Date time input form element specifically for DIPS forms",
        GroupName = "DIPS Form",
        Order = 5000)]
    [FormsSampleImage(nameof(DateTimeElementBlock))]
    public class DipsDateTimeElementBlock : DateTimeElementBlock
    {
        /// <summary>
        /// Gets or sets the dips mapping property.
        /// </summary>
        /// <value>The dips mapping property.</value>
        [Display(
            Name = "DIPS Mapping Property",
            Description = "The DIPS form property this element maps to",
            GroupName = SystemTabNames.Content,
            Order = 10
        )]
        [Required]
        [BackingType(typeof(PropertyNumber))]
        [EditorDescriptor(EditorDescriptorType = typeof(EnumEditorDescriptor<DipsFormElement>))]
        public virtual DipsFormElement DipsMappingProperty { get; set; }
    }
}

No worries - let me know if you have any questions regarding the code

Looking your error in console, it seems that you are creating custom element and forgot to register method for binding data into your controls, something look like:

CustomBindingElements: {
            "EPiServer.Forms.Samples.Implementation.Elements.DateTimeElementBlock": function (elementInfo, val) {

            ....

Pleases see the Forms Sample for details how to do that:

https://github.com/episerver/EPiServer.Forms.Samples/blob/master/ClientResources/ViewMode/EPiServerFormsSamples.js

Yes, Dac Thach's answer seems to be right.

Brilliant thanks guys!