TryUpdateModelAsync returns true but model is empty

Question

I'm pretty new to this stuff, so I won't be surprised if I'm just way off on what to do. I'm working on an app that does the following: Pull Data into a Model -> Create Edit UI for Model -> Update Model with User Edits -> Save Model to DB -> Create Word Document Template Using Model.

I've done I have a working UI that fetches the data into a model and puts it into an editable UI using @HTML.TextBoxFor(m => m.item) and what not. Now I'm trying to use those html helpers to update the model with the user edits so that I can save the model and use it elsewhere. I can't seem to figure out how to update the model. Here is some additional context:

I have created a complex model that looks something like this:

public class DataModel
{
    public int ID1 { get; set; }
    public int ID2 { get; set; }
    public List Items{ get; set; }
    public List Stuff{ get; set; }
    public List Things{ get; set; }
}

I have a UI with a bunch of HTML helpers like: @Html.TextBoxFor(m => m.Items[3].itemname)

At the bottom of the UI, I have a button with an AJAX call attached to it

function updateData() {
    let tableContainer = $("#generateDataContainer");

    try {
        tableContainer.empty();
        //add spinner
        tableContainer.html(' Loading... ')

        $.ajax({
            url: "/@ViewContext.RouteData.Values["controller"]/UpdateModelData",
            cache: false,
            type: "get",
            data: {
            },
            contentType: "application/json",
            dataType: "html",
            success: function (result) {
                tableContainer.empty();
                tableContainer.html(result);
            },
            error: function (request, status, error) {
                tableContainer.empty();
            },
        });
    }
    catch (e) {
        console.log(e);
    }

In the controller I have the following function:

    public async Task UpdateDataAsync()
    {

        DataModel model = new DataModel();
        await TryUpdateModelAsync(model);
        return PartialView("_Generate", model);
    }

Currently, I'm just trying to display the model to verify changes using @Html.DisplayForModel(). Right now, the output that I'm getting is ID1 0 ID2 0 and nothing for the lists.

My first thought was that the TryUpdateModelAsync was failing, but when I tested this using an if statement, it returned true. So it seems that it is returning true without actually updating the model. What am I doing wrong? Thanks,

TryUpdateModelAsync returns true but model is empty

0 Answers