Custom NewForm , Redirect to a custom page using Powershell

Question

I could achieve this i.e. creating a list's NewForm named CustomNewForm.aspx setting it as Default NewForm and editing it in advanced mode to add a script code which redirects to CustomForm.aspx Page using code
window.location.href = "/sites/<Site Collection Name>/SitePages/CustomForm.aspx"

Using SharePoint Designer but as per deployment is concerned I need to achieve this using Powershell only. Is there a way to do the above two steps using Powershell or is there a better solution to achieve the task of mainly to redirect to CustomForm Page (The CustomForm.aspx page has custom UI and consist of jsom code to create a new ListItem) for creating new item in the list and making it available on the click of New item button.

Answer 1

Use the following CSOM code to update the NewFormUrl property of the list item content type.

            ClientContext ctx = new ClientContext("http://spm:5002/sites/test");
            Web web = ctx.Web;
            List test = web.Lists.GetByTitle("TestList");
            ContentTypeCollection ct = test.ContentTypes;
            ctx.Load(ct);
            ctx.ExecuteQuery();

            ContentType item = ct.Where(x => x.Name.Equals("Item")).FirstOrDefault();
            Console.WriteLine(item.Name + ", " + item.Id + ", " + item.NewFormUrl);
            item.NewFormUrl = "SitePages/asd.aspx";
            item.Update(false);
            ctx.ExecuteQuery();

Now whenever you click on New Item it will open the desired page. Also note that item.Update(false); statement is going to update the content type. The false as function parameter used to not update the derived content type.