I created a component for a dual list box. Everything is fine but when I submit I get an error.
<EditForm Model="Model.Report" class="kt-form" OnValidSubmit="Model.OnSearch">
<div class="modal-header">
<h5 class="modal-title" id="exampleModalLabel">Edit Columns</h5>
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
</button>
</div>
<div class="modal-body">
<div class="row">
<div class="col-md-12">
<Project.Components.DualListbox ReportColumns="Model.Report.ReportColumns" Id="ReportColumns" @bind-Value="@Model.Report.ReportColumns"></Project.Components.DualListbox>
</div>
</div>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary btn-sm" @onclick="Model.OnCloseModal"><i class="la la-close"></i> Close</button>
<button type="submit" class="btn btn-primary btn-sm"><i class="la la-exchange"></i> Change</button>
</div>
</EditForm>
DualListbox
Razor code:
@typeparam TValue
@inherits InputBase<TValue>
@if (ReportColumns != null)
{
<select id="@Id" class="kt-dual-listbox" multiple>
@foreach (var column in ReportColumns.OrderBy(c => c.Sort))
{
if (column.IsChecked == 1)
{
<option value="@column.Id" selected>@column.Title</option>
}
else
{
<option value="@column.Id">@column.Title</option>
}
}
</select>
}
*DualListbox
code-behind *:
using Project.Models;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Forms;
using Microsoft.JSInterop;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Threading.Tasks;
namespace Project.Components
{
public partial class DualListbox<TValue> : InputBase<TValue>
{
[Parameter] public string Id { get; set; }
[Inject] IJSRuntime JSRuntime { get; set; }
[Parameter] public ICollection<ReportColumn> ReportColumns { get; set; }
public DotNetObjectReference<DualListbox<TValue>> DotNetRef;
[Parameter] public EventCallback<object> OnChanged { get; set; }
protected override bool TryParseValueFromString(string value, out TValue result, out string validationErrorMessage)
{
try
{
if (value == "null")
{
value = null;
}
if (typeof(TValue) == typeof(string))
{
result = (TValue)(object)value;
validationErrorMessage = null;
return true;
}
else if (typeof(TValue) == typeof(int) || typeof(TValue) == typeof(int?))
{
int.TryParse(value, NumberStyles.Integer, CultureInfo.InvariantCulture, out var parsedValue);
result = (TValue)(object)parsedValue;
validationErrorMessage = null;
return true;
}
throw new InvalidOperationException($"{GetType()} does not support the type '{typeof(TValue)}'.");
}
catch (Exception ex)
{
throw ex;
}
}
protected override void OnInitialized()
{
base.OnInitialized();
DotNetRef = DotNetObjectReference.Create(this);
}
protected override async Task OnAfterRenderAsync(bool firstRender)
{
await base.OnAfterRenderAsync(firstRender);
if (firstRender)
{
await JSRuntime.InvokeVoidAsync("dualListboxComponent.init", Id, DotNetRef, "Change_SelectWithFilterBase");
}
}
[JSInvokable("Change_SelectWithFilterBase")]
public void Change(string value)
{
try
{
if (value == "null")
{
value = null;
}
var array = value.Split("#");
if (array[0] == "add")
{
int _value = int.Parse(array[1]);
var report = ReportColumns.Where(c => c.Id == _value).FirstOrDefault();
report.IsChecked = 1;
}
else
{
int _value = int.Parse(array[1]);
var report = ReportColumns.Where(c => c.Id == _value).FirstOrDefault();
report.IsChecked = 0;
}
}
catch (Exception ex)
{
throw ex;
}
if (OnChanged.HasDelegate)
OnChanged.InvokeAsync(value);
}
}
}
[2020-02-12T07:42:28.867Z] Error: There was an error applying batch 7. e.log @ blazor.server.js:15 blazor.server.js:8 Uncaught (in promise)
TypeError: Cannot read property 'insertBefore' of null at Object.s [as insertLogicalChild] (blazor.server.js:8) at e.insertText (blazor.server.js:8) at e.insertFrame (blazor.server.js:8) at e.applyEdits (blazor.server.js:8) at e.updateComponent (blazor.server.js:8) at Object.t.renderBatch (blazor.server.js:1) at e. (blazor.server.js:15) at blazor.server.js:15 at Object.next (blazor.server.js:15) at blazor.server.js:15 blazor.server.js:15 [2020-02-12T07:42:28.926Z] Error: System.AggregateException: One or more errors occurred. (TypeError: Cannot read property 'insertBefore' of null) ---> System.InvalidOperationException: TypeError: Cannot read property 'insertBefore' of null at Microsoft.AspNetCore.Components.RenderTree.Renderer.InvokeRenderCompletedCallsAfterUpdateDisplayTask(Task updateDisplayTask, Int32[] updatedComponents) --- End of inner exception stack trace ---
My problem was in FontAwesome too. In my case, put icons inside <span></span>
solved problems.
@if (conditional)
{
<span>
<i class="fas fa-check"></i>
</span>
}
else
{
<span>
<i class="fas fa-times"></i>
</span>
}
So, this may not be your exact answer, but it may give a clue to someone who stumbles upon this SO question. In my case, this was the result of swapping out a Font Awesome icon within button text as opposed to using two separate buttons.
This may be related because you are using the JSRuntime in combination with "report.IsChecked = 1;" syntax, which I assume is changing UI element state client-side that Blazor Server is trying to (but unable) to track.
When I used conditional logic within a single button to swap out the icon, I received an error, "blazor TypeError: Cannot read property 'removeChild' of null". This syntax using two separate buttons, however, worked just fine:
@if (AllowAllPartners)
{
<button @onclick="(() => AllowAllPartnersToggle())">
<i class="far fa-check-square"></i>
</button>
}
else
{
<button @onclick="(() => AllowAllPartnersToggle())">
<i class="far fa-square"></i>
</button>
}
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