Engine.Razor.Run causes InvalidCastException - razor

Question

I have the following code to get my cshtml Email Template.
try
{
var layoutTemplateKey = new NameOnlyTemplateKey("layout", ResolveType.Global, null);
if (!Engine.Razor.IsTemplateCached(layoutTemplateKey, null))
Engine.Razor.AddTemplate(layoutTemplateKey, ReadTemplateFile("/Views/Email/Layout.cshtml"));
var templateKey = new NameOnlyTemplateKey(templatePath, ResolveType.Global, null);
if (!Engine.Razor.IsTemplateCached(templateKey, viewModel.GetType()))
{
Engine.Razor.AddTemplate(templateKey, ReadTemplateFile(templatePath));
Engine.Razor.Compile(templateKey, viewModel.GetType());
}
return viewModel == null ?
Engine.Razor.Run(templateKey) :
Engine.Razor.Run(templateKey, viewModel.GetType(), viewModel);
}
catch (Exception ex)
{
return ex.Message;
}
However My the Engine.Razor.Run causes InvalidCastException with a model which is no where referenced here.
And it continuously happens with any other models too.
The recent change I was done was inheriting each of this class by another Model to be used in the Layout.cshtml.
Expected Model: NewBookRecievedEmailViewModel
public class NewBookRecievedEmailViewModel : EmailHelperModel
{
public ProposalPostedEmailViewModel()
{
this.canBeDeleted = true;
}
public string BookName { get; set; }
public string Author {get; set;}
}
Gets error with Model PayOutBookEmailViewModel
public class PayOutBookEmailViewModel : EmailHelperModel
{
public string BookID { get; set; }
public string BookUrl {get; set;}
}
And the inherited Model is : EmailHelper
public class EmailHelperModel
{
public bool canBeDeleted { get; set; }
public string DeleteUrl { get; set; }
}
Stack Trace:
at RazorEngine.Templating.TemplateBase`1.SetModel(Object model)
at RazorEngine.Templating.TemplateBase.SetData(Object model, DynamicViewBag viewbag)
at RazorEngine.Templating.RazorEngineCore.CreateTemplate(ICompiledTemplate template, Object model, DynamicViewBag viewbag)
at RazorEngine.Templating.RazorEngineCoreWithCache.ResolveInternal(String cacheName, Object model, Type modelType, DynamicViewBag viewbag, ResolveType resolveType, ITemplateKey context)
at RazorEngine.Templating.InternalTemplateService.Resolve(String name, Object model, Type modelType, DynamicViewBag viewbag, ResolveType resolveType)
at RazorEngine.Templating.TemplateBase`1.ResolveLayout(String name)
at RazorEngine.Templating.TemplateBase.RazorEngine.Templating.ITemplate.Run(ExecuteContext context, TextWriter reader)
at RazorEngine.Templating.RazorEngineCore.RunTemplate(ICompiledTemplate template, TextWriter writer, Object model, DynamicViewBag viewBag)
at RazorEngine.Templating.RazorEngineService.Run(ITemplateKey key, TextWriter writer, Type modelType, Object model, DynamicViewBag viewBag)
at RazorEngine.Templating.DynamicWrapperService.Run(ITemplateKey key, TextWriter writer, Type modelType, Object model, DynamicViewBag viewBag)
at RazorEngine.Templating.RazorEngineServiceExtensions.<>c__DisplayClass22_0.<Run>b__0(TextWriter writer)
at RazorEngine.Templating.RazorEngineServiceExtensions.WithWriter(Action`1 withWriter)
at RazorEngine.Templating.RazorEngineServiceExtensions.Run(IRazorEngineService service, ITemplateKey key, Type modelType, Object model, DynamicViewBag viewBag)
at Pxp.Api.Helpers.EmailHelper.GetHtmlContent(String templatePath, Object viewModel)

Answer 1

Instead of using cshtml, consider using actual HTML; or better yet, generating elements with JavaScript, it's the real way-to-go, here' some sample code of how to create an element in JavaScript:
var MyEngine = new (function() {
this.el = function(opts) {
if(!svgList.split(" ").find(x => x == opts.tag)) {
this.node = document.createElement(opts.tag || "div");
} else {
this.node = document.createElementNS('http://www.w3.org/2000/svg', opts.tag);
}
for(var k in opts) {
if(k == "style") {
for(var s in opts[k]) {
this.node.style[s] = opts[k][s];
}
} else if(k != "parent"){
this.node[k] = opts[k];
}
}
this.setAttrs = (attrs) => {
for(var k in attrs) {
this.node.setAttribute(k, attrs[k]);
}
};
this.getAttr = (at) => {
return this.node.getAttribute(at);
};
this.setStyle = (stl) => {
for(var k in stl) {
this.node.style[k] = stl[k];
}
}
var attr = opts.attr || {};
this.setAttrs(attr);
var optsPar = opts.parent;
var par = null;
if(optsPar) {
if(optsPar.constructor == String) {
par = f("#" + optsPar);
} else if(optsPar instanceof Element) {
par = optsPar;
}
}
this.parent = par || document.body || {appendChild: (d) => {}};
this.parent.appendChild(this.node);
};
)();
then to create a new element:
var temp = new MyEngine.el({
id:"hi",
style:{position:absolute, left:100+"px"},
innerHTML:"<b>nice to meet you</b>
});