Form System Flexibility improvements (#4774)

* Introduce very flexible form input system

* Refactorings after rebase

* Test fix

* Update BTCPayServer/Forms/FormDataService.cs

---------

Co-authored-by: Dennis Reimann <mail@dennisreimann.de>

BTCPayServer.Abstractions/Form/Form.cs

@@ -135,25 +135,5 @@ public class Form
         }
     }
 
-    public JObject GetValues()
+
-    {
-        var r = new JObject();
-        foreach (var f in GetAllFields())
-        {
-            var node = r;
-            for (int i = 0; i < f.Path.Count - 1; i++)
-            {
-                var p = f.Path[i];
-                var child = node[p] as JObject;
-                if (child is null)
-                {
-                    child = new JObject();
-                    node[p] = child;
-                }
-                node = child;
-            }
-            node[f.Field.Name] = f.Field.Value;
-        }
-        return r;
-    }
 }

BTCPayServer.Tests/FormTests.cs

@@ -1,6 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using BTCPayServer.Abstractions.Form;
 using BTCPayServer.Forms;
@@ -42,9 +40,10 @@ public class FormTests : UnitTestBase
                 }
             }
         };
-        var service = new FormDataService(null, null);
+        var providers = new FormComponentProviders(new List<IFormComponentProvider>());
+        var service = new FormDataService(null, providers);
         Assert.False(service.IsFormSchemaValid(form.ToString(), out _, out _));
-        form = new Form()
+        form = new Form
         {
             Fields = new List<Field>
             {
@@ -161,12 +160,12 @@ public class FormTests : UnitTestBase
             }
         }
 
-        var obj = form.GetValues();
+        var obj = service.GetValues(form);
         Assert.Equal("original", obj["invoice"]["test"].Value<string>());
         Assert.Equal("updated", obj["invoice_item3"].Value<string>());
         Clear(form);
         form.SetValues(obj);
-        obj = form.GetValues();
+        obj = service.GetValues(form);
         Assert.Equal("original", obj["invoice"]["test"].Value<string>());
         Assert.Equal("updated", obj["invoice_item3"].Value<string>());
 
@@ -184,10 +183,10 @@ public class FormTests : UnitTestBase
             }
         };
         form.SetValues(obj);
-        obj = form.GetValues();
+        obj = service.GetValues(form);
         Assert.Null(obj["test"].Value<string>());
         form.SetValues(new JObject{ ["test"] = "hello" });
-        obj = form.GetValues();
+        obj = service.GetValues(form);
         Assert.Equal("hello", obj["test"].Value<string>());
     }
 

BTCPayServer/Controllers/UICustodianAccountsController.cs

@@ -11,6 +11,7 @@ using BTCPayServer.Client;
 using BTCPayServer.Client.Models;
 using BTCPayServer.Data;
 using BTCPayServer.Filters;
+using BTCPayServer.Forms;
 using BTCPayServer.Models.CustodianAccountViewModels;
 using BTCPayServer.Payments;
 using BTCPayServer.Services;
@@ -38,6 +39,7 @@ namespace BTCPayServer.Controllers
         private readonly BTCPayServerClient _btcPayServerClient;
         private readonly BTCPayNetworkProvider _networkProvider;
         private readonly LinkGenerator _linkGenerator;
+        private readonly FormDataService _formDataService;
 
         public UICustodianAccountsController(
             DisplayFormatter displayFormatter,
@@ -46,7 +48,8 @@ namespace BTCPayServer.Controllers
             IEnumerable<ICustodian> custodianRegistry,
             BTCPayServerClient btcPayServerClient,
             BTCPayNetworkProvider networkProvider,
-            LinkGenerator linkGenerator
+            LinkGenerator linkGenerator,
+            FormDataService formDataService
         )
         {
             _displayFormatter = displayFormatter;
@@ -55,6 +58,7 @@ namespace BTCPayServer.Controllers
             _btcPayServerClient = btcPayServerClient;
             _networkProvider = networkProvider;
             _linkGenerator = linkGenerator;
+            _formDataService = formDataService;
         }
 
         public string CreatedCustodianAccountId { get; set; }
@@ -247,7 +251,7 @@ namespace BTCPayServer.Controllers
 
             if (configForm.IsValid())
             {
-                var newData = configForm.GetValues();
+                var newData = _formDataService.GetValues(configForm);
                 custodianAccount.SetBlob(newData);
                 custodianAccount = await _custodianAccountRepository.CreateOrUpdate(custodianAccount);
                 return RedirectToAction(nameof(ViewCustodianAccount),
@@ -301,7 +305,7 @@ namespace BTCPayServer.Controllers
             configForm.ApplyValuesFromForm(Request.Form);
             if (configForm.IsValid())
             {
-                var configData = configForm.GetValues();
+                var configData = _formDataService.GetValues(configForm);
                 custodianAccountData.SetBlob(configData);
                 custodianAccountData = await _custodianAccountRepository.CreateOrUpdate(custodianAccountData);
                 TempData[WellKnownTempData.SuccessMessage] = "Custodian account successfully created";

BTCPayServer/Controllers/UIPaymentRequestController.cs

@@ -240,7 +240,7 @@ namespace BTCPayServer.Controllers
                 form.ApplyValuesFromForm(Request.Form);
                 if (FormDataService.Validate(form, ModelState))
                 {  
-                    prBlob.FormResponse = form.GetValues();
+                    prBlob.FormResponse = FormDataService.GetValues(form);
                     result.SetBlob(prBlob);
                     await _PaymentRequestRepository.CreateOrUpdatePaymentRequest(result);
                     return RedirectToAction("PayPaymentRequest", new {payReqId});

BTCPayServer/Forms/FormDataExtensions.cs

@@ -1,4 +1,3 @@
-using BTCPayServer.Abstractions.Form;
 using BTCPayServer.Data;
 using Microsoft.Extensions.DependencyInjection;
 using Newtonsoft.Json;
@@ -15,6 +14,7 @@ public static class FormDataExtensions
         serviceCollection.AddSingleton<IFormComponentProvider, HtmlInputFormProvider>();
         serviceCollection.AddSingleton<IFormComponentProvider, HtmlFieldsetFormProvider>();
         serviceCollection.AddSingleton<IFormComponentProvider, HtmlSelectFormProvider>();
+        serviceCollection.AddSingleton<IFormComponentProvider, FieldValueMirror>();
     }
     
     public static JObject Deserialize(this FormData form) 

BTCPayServer/Forms/FormDataService.cs

@@ -11,6 +11,7 @@ using BTCPayServer.Data;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.EntityFrameworkCore;
+using Newtonsoft.Json.Linq;
 
 namespace BTCPayServer.Forms;
 
@@ -150,14 +151,50 @@ public class FormDataService
 
     public CreateInvoiceRequest GenerateInvoiceParametersFromForm(Form form)
     {
-        var amt = form.GetFieldByFullName($"{InvoiceParameterPrefix}amount")?.Value;
+        var amt = GetValue(form, $"{InvoiceParameterPrefix}amount");
         return new CreateInvoiceRequest
         {
-            Currency = form.GetFieldByFullName($"{InvoiceParameterPrefix}currency")?.Value,
+            Currency = GetValue(form, $"{InvoiceParameterPrefix}currency"),
             Amount = string.IsNullOrEmpty(amt) ? null : decimal.Parse(amt, CultureInfo.InvariantCulture),
-            
+            Metadata = GetValues(form),
-            Metadata = form.GetValues(),
-            
         };
     }
+
+    public string? GetValue(Form form, string field)
+    {
+        return GetValue(form, form.GetFieldByFullName(field));
+    }
+
+    public string? GetValue(Form form, Field? field)
+    {
+        if (field is null)
+        {
+            return null;
+        }
+        return _formProviders.TypeToComponentProvider.TryGetValue(field.Type, out var formComponentProvider) ? formComponentProvider.GetValue(form, field) : field.Value;
+    }
+
+    public JObject GetValues(Form form)
+    {
+        var r = new JObject();
+        
+        foreach (var f in form.GetAllFields())
+        {
+            var node = r;
+            for (int i = 0; i < f.Path.Count - 1; i++)
+            {
+                var p = f.Path[i];
+                var child = node[p] as JObject;
+                if (child is null)
+                {
+                    child = new JObject();
+                    node[p] = child;
+                }
+                node = child;
+            }
+
+            node[f.Field.Name] = GetValue(form, f.FullName);
+        }
+        return r;
+    }
 }

BTCPayServer/Forms/HtmlFieldsetFormProvider.cs

@@ -1,5 +1,4 @@
 using System.Collections.Generic;
-using System.Linq;
 using BTCPayServer.Abstractions.Form;
 
 namespace BTCPayServer.Forms;
@@ -13,8 +12,9 @@ public class HtmlFieldsetFormProvider : IFormComponentProvider
         typeToComponentProvider.Add("fieldset", this);
     }
 
-    public void Validate(Field field)
+    public string GetValue(Form form, Field field)
     {
+        return null;
     }
 
     public void Validate(Form form, Field field)

BTCPayServer/Forms/HtmlInputFormProvider.cs

@@ -1,11 +1,31 @@
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
-using System.Linq;
 using BTCPayServer.Abstractions.Form;
 using BTCPayServer.Validation;
 
 namespace BTCPayServer.Forms;
 
+public class FieldValueMirror : IFormComponentProvider
+{
+    public string View { get; } = null;
+    public void Validate(Form form, Field field)
+    {
+        if (form.GetFieldByFullName(field.Value) is null)
+        {
+            field.ValidationErrors = new List<string>() {$"{field.Name} requires {field.Value} to be present"};
+        }
+    }
+
+    public void Register(Dictionary<string, IFormComponentProvider> typeToComponentProvider)
+    {
+        typeToComponentProvider.Add("mirror", this);
+    }
+
+    public string GetValue(Form form, Field field)
+    {
+        return form.GetFieldByFullName(field.Value)?.Value;
+    }
+}
 public class HtmlInputFormProvider : FormComponentProviderBase
 {
     public override void Register(Dictionary<string, IFormComponentProvider> typeToComponentProvider)

BTCPayServer/Forms/HtmlSelectFormProvider.cs

@@ -1,8 +1,6 @@
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
-using System.Linq;
 using BTCPayServer.Abstractions.Form;
-using BTCPayServer.Validation;
 using Microsoft.AspNetCore.Mvc.Rendering;
 
 namespace BTCPayServer.Forms;

BTCPayServer/Forms/IFormComponentProvider.cs

@@ -9,12 +9,18 @@ public interface IFormComponentProvider
     string View { get; }
     void Validate(Form form, Field field);
     void Register(Dictionary<string, IFormComponentProvider> typeToComponentProvider);
+    string GetValue(Form form, Field field);
 }
 
 public abstract class FormComponentProviderBase : IFormComponentProvider
 {
     public abstract string View { get; }
     public abstract void Register(Dictionary<string, IFormComponentProvider> typeToComponentProvider);
+    public virtual string GetValue(Form form, Field field)
+    {
+        return field.Value;
+    }
+
     public abstract void Validate(Form form, Field field);
 
     public void ValidateField<T>(Field field) where T : ValidationAttribute, new()

BTCPayServer/Plugins/PointOfSale/Controllers/UIPointOfSaleController.cs

@@ -267,7 +267,7 @@ namespace BTCPayServer.Plugins.PointOfSale.Controllers
                         return RedirectToAction(nameof(ViewPointOfSale), new { appId, viewType });
                     }
 
-                    formResponseJObject = form.GetValues();
+                    formResponseJObject = FormDataService.GetValues(form);
                     break;
             }
             try
@@ -406,7 +406,7 @@ namespace BTCPayServer.Plugins.PointOfSale.Controllers
                     var controller = nameof(UIPointOfSaleController).TrimEnd("Controller", StringComparison.InvariantCulture);
                     var redirectUrl =
                         Request.GetAbsoluteUri(Url.Action(nameof(ViewPointOfSale), controller, new {appId, viewType}));
-                    formParameters.Add("formResponse", form.GetValues().ToString());
+                    formParameters.Add("formResponse", FormDataService.GetValues(form).ToString());
                     return View("PostRedirect", new PostRedirectViewModel
                     {
                         FormUrl = redirectUrl,

BTCPayServer/Views/Shared/Forms/FieldSetElement.cshtml

@@ -8,7 +8,7 @@
         <legend class="h3 mt-4 mb-3">@Model.Label</legend>
         @foreach (var field in Model.Fields)
         {
-			if (FormComponentProviders.TypeToComponentProvider.TryGetValue(field.Type, out var partial))
+			if (FormComponentProviders.TypeToComponentProvider.TryGetValue(field.Type, out var partial) && !string.IsNullOrEmpty(partial.View))
 			{
 			    field.Name = $"{(string.IsNullOrEmpty(Model.Name)? string.Empty: $"{Model.Name}_")}{field.Name}";
 			    <partial name="@partial.View" for="@field"></partial>

BTCPayServer/Views/Shared/_Form.cshtml

@@ -5,7 +5,7 @@
 
 @foreach (var field in Model.Fields)
 {
-    if (FormComponentProviders.TypeToComponentProvider.TryGetValue(field.Type, out var partial))
+    if (FormComponentProviders.TypeToComponentProvider.TryGetValue(field.Type, out var partial) && !string.IsNullOrEmpty(partial.View))
     {
         <partial name="@partial.View" for="@field" />
     }