Tiny Editor doesn't show on close of Bootstrap Popup - asp.net-core

Question

I'm using the TinyMCE Editor version 5.6.1. Whenever I load my popup for the first time, I get the following:
When I close the Popup and re-display it again, I get the following:
There are no errors in the console and loading the Popup is as plain as you can get it:
<div class="modal" tabindex="-1" role="dialog" id="form-modal">
<div class="modal-dialog modal-lg modal-dialog-scrollable">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title"></h5>
<button type="button" class="close" data-dismiss="modal">
<span>×</span>
</button>
</div>
<div class="modal-body">
</div>
</div>
</div>
</div>
Here is the code which calls the Modal
#{
ViewData["Title"] = "Product Administration";
}
<br />
<div class="modal" tabindex="-1" role="dialog" id="form-modal">
<div class="modal-dialog modal-lg modal-dialog-scrollable">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title"></h5>
<button type="button" class="close" data-dismiss="modal">
<span>×</span>
</button>
</div>
<div class="modal-body">
</div>
</div>
</div>
</div>
<div class="shadow-lg p-1 mb-1 bg-primary rounded d-flex">
<h5 class="text-white flex-grow-1">Product Administration ...</h5>
<div>
<a onclick="showInPopup('#Url.Action("AddEdit","Product",null,Context.Request.Scheme)','New Product')"
class="btn btn-success text-white">
<i class="fas fa-random"></i>New Product</a>
</div>
</div>
Here is the code for the Modal:
#model ProductEdit
#{
Layout = null;
}
<script>tinymce.init({
selector: 'textarea',
menubar: false,
plugins: [
'advlist autolink lists link image charmap print preview anchor',
'searchreplace visualblocks code fullscreen',
'insertdatetime media table paste code help wordcount'
],
toolbar: 'undo redo | formatselect | ' +
'bold italic backcolor | alignleft aligncenter ' +
'alignright alignjustify | bullist numlist outdent indent | ' +
'removeformat | help',
content_css: '//www.tiny.cloud/css/codepen.min.css'
});</script>
<div class="row">
<div class="col-lg-12">
<form asp-action="AddEdit" asp-route-id="#Model.Id" onsubmit="return jQueryAjaxPost(this, RefreshMe, false);" autocomplete="off">
<input type="hidden" asp-for="#Model.Id" />
<div id="errValidation" class="alert alert-dismissible alert-danger" data-content="ok">
<button id="closeValidation" type="button" class="close">×</button>
<div id="errTitle" class="font-weight-bolder">Oh snap!</div>
<div id="errDetails">An Error Occured!</div>
</div>
<div class="row">
<div class="col-lg-4">
<div class="form-group">
<label asp-for="#Model.CategoryId" class="control-label"></label>
<select asp-for="#Model.CategoryId"
class="form-control"
asp-items="#(new SelectList(Model.ProductCategories,"Id","Display"))">
</select>
<span asp-validation-for="#Model.CategoryId" class="text-danger"></span>
</div>
</div>
<div class="col-lg-4">
<div class="form-group">
<label asp-for="#Model.SectionId" class="control-label"></label>
<select asp-for="#Model.SectionId"
class="form-control"
asp-items="#(new SelectList(Model.ProposalSections,"Id","Display"))">
</select>
<span asp-validation-for="#Model.SectionId" class="text-danger"></span>
</div>
</div>
<div class="col-lg-4">
<div class="form-group">
<label asp-for="#Model.ManufacturerId" class="control-label"></label>
<select asp-for="#Model.ManufacturerId"
class="form-control"
asp-items="#(new SelectList(Model.Manufacturers,"Id","Display"))">
</select>
<span asp-validation-for="#Model.ManufacturerId" class="text-danger"></span>
</div>
</div>
</div>
<div class="row">
<div class="col-lg-6">
<div class="form-group mb-2 has-warning has-feedback">
<label asp-for="#Model.InternalPartNumber" class="control-label"></label>
<input asp-for="#Model.InternalPartNumber" class="form-control"></>
<span asp-validation-for="#Model.InternalPartNumber" class="text-danger"></span>
</div>
</div>
<div class="col-lg-6">
<div class="form-group mb-2 has-warning has-feedback">
<label asp-for="#Model.ManufacturerPartNumber" class="control-label"></label>
<input asp-for="#Model.ManufacturerPartNumber" class="form-control"></>
<span asp-validation-for="#Model.ManufacturerPartNumber" class="text-danger"></span>
</div>
</div>
</div>
<div class="form-group">
<label asp-for="#Model.Description" class="control-label"></label>
<input asp-for="#Model.Description" class="form-control" rows="2"></>
<span asp-validation-for="#Model.Description" class="text-danger"></span>
</div>
<div class="row">
<div class="col-lg-6">
<div class="form-group">
<label asp-for="#Model.SellPrice" class="control-label"></label>
<div class="input-group">
<div class="input-group-prepend">
<div class="input-group-text">
<i class="fas fa-dollar-sign"></i>
</div>
</div>
<input asp-for="#Model.SellPrice" class="form-control"></>
</div>
<span asp-validation-for="#Model.SellPrice" class="text-danger"></span>
</div>
</div>
<div class="col-lg-6">
<div class="form-group">
<label asp-for="#Model.Cost" class="control-label"></label>
<div class="input-group">
<div class="input-group-prepend">
<div class="input-group-text">
<i class="fas fa-dollar-sign"></i>
</div>
</div>
<input asp-for="#Model.Cost" class="form-control"></>
</div>
<span asp-validation-for="#Model.Cost" class="text-danger"></span>
</div>
</div>
</div>
<div class="form-group">
<label asp-for="#Model.ProductWebsite" class="control-label"></label>
<input asp-for="#Model.ProductWebsite" class="form-control"></>
<span asp-validation-for="#Model.ProductWebsite" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="#Model.Note" class="control-label"></label>
<textarea asp-for="#Model.Note" class="form-control" rows="5"></textarea>
<span asp-validation-for="#Model.Note" class="text-danger"></span>
</div>
<div class="d-flex">
<div class="form-group mr-2">
<input asp-for="#Model.Active" />
<label asp-for="#Model.Active" class="control-label text-success"></label>
</div>
<div><button type="submit" value="Save" class="btn btn-success mr-2">Save Changes</button></div>
<div><input type="reset" class="btn btn-warning"></></div>
</div>
</form>
</div>
</div>
<script>
$('#errValidation').hide();
$(function () {
$("#SectionId").chosen({ no_results_text: "Oops, Section not found!", disable_search_threshold: 4 });
$("#CategoryId").chosen({ no_results_text: "Oops, Category not found!" });
$("#ManufacturerId").chosen({ no_results_text: "Oops, Manufacturer not found!" });
});
$("#closeValidation").click(function () {
$("#errValidation").hide();
});
function RefreshMe() {
$('#products').DataTable().ajax.reload(null, false);
showSuccessToast('Product Saved', 'top-center');
}
</script>
The showInPopup method is the following:
showInPopup = (url, title) => {
$.ajax({
type: "GET",
url: url,
success: function (res) {
$('#form-modal .modal-body').html(res);
$('#form-modal .modal-title').html(title);
$('#form-modal').modal('show');
}
})
}
Any ideas about what might be happening? If I refresh the page it works again only for the first load.
Thanks.
--- Val

Answer 1

From the second pictures, the textare is not rendered by tinymce, because the html which ajax returned can not be rendered by tinymce. TinyMCE works when the page is building. So a better method is to use #Html.Partial to load the partial view (ProductEdit).
In the view Product Administration, change the modal body.
<div class="modal-header">
<h5 class="modal-title">#Context.Request.Scheme</h5>
<button type="button" class="close" data-dismiss="modal">
<span>×</span>
</button>
</div>
<div class="modal-body">
#Html.Partial("addedit.cshtml",Model)
</div>
Change this javascript method.
var showInPopup = (url, title) => {
$('#form-modal').modal('show');
}
And move tinymce.init({ //... }) to this view Product Administration.
Then, TinyMCE will work well.