V15: Serverside Media Picker Validation (#18429)

* Add TypedJsonValidator to avoid duplicate serialization

* Add allowed type validator

* Validate multiple media toggle

* Add startnode validator

* Fix tests

* Add validation tests

* Apply suggestions from code review

Co-authored-by: Andy Butland <abutland73@gmail.com>

* Add XML docs

* Remove unnecessary obsolete constructor

* Avoid multiple checks

* Use value instead of specific member names

* Remove test

* Optimize StartNodeValidator

* Clarify Validates_Allowed_Type

---------

Co-authored-by: Andy Butland <abutland73@gmail.com>

src/Umbraco.Core/EmbeddedResources/Lang/da.xml

@@ -113,6 +113,9 @@ Mange hilsner fra Umbraco robotten
     <key alias="entriesShort"><![CDATA[Minimum %0% element(er), tilføj <strong>%1%</strong> mere.]]></key>
     <key alias="entriesExceed"><![CDATA[Maksimum %0% element(er), <strong>%1%</strong> for mange.]]></key>
     <key alias="entriesAreasMismatch">Ét eller flere områder lever ikke op til kravene for antal indholdselementer.</key>
+    <key alias="invalidMediaType">Den valgte medie type er ugyldig.</key>
+    <key alias="multipleMediaNotAllowed">Det er kun tilladt at vælge ét medie.</key>
+    <key alias="invalidStartNode">Valgt medie kommer fra en ugyldig mappe.</key>
   </area>
   <area alias="recycleBin">
     <key alias="contentTrashed">Slettet indhold med Id: {0} Relateret til original "parent" med id: {1}</key>
@@ -124,4 +127,4 @@ Mange hilsner fra Umbraco robotten
     <key alias="FileWriting">Filskrivning</key>
     <key alias="MediaFolderCreation">Mediemappeoprettelse</key>
   </area>
-</language>
+</language>

src/Umbraco.Core/EmbeddedResources/Lang/en.xml

@@ -387,6 +387,9 @@
     <key alias="duplicateUserGroupName">User group name '%0%' is already taken</key>
     <key alias="duplicateMemberGroupName">Member group name '%0%' is already taken</key>
     <key alias="duplicateUsername">Username '%0%' is already taken</key>
+    <key alias="invalidMediaType">The chosen media type is invalid.</key>
+    <key alias="multipleMediaNotAllowed">Multiple selected media is not allowed.</key>
+    <key alias="invalidStartNode">The selected media is from the wrong folder.</key>
   </area>
   <area alias="healthcheck">
     <!-- The following keys get these tokens passed in:

src/Umbraco.Core/EmbeddedResources/Lang/en_us.xml

@@ -388,6 +388,9 @@
     <key alias="entriesShort"><![CDATA[Minimum %0% entries, requires <strong>%1%</strong> more.]]></key>
     <key alias="entriesExceed"><![CDATA[Maximum %0% entries, <strong>%1%</strong> too many.]]></key>
     <key alias="entriesAreasMismatch">The content amount requirements are not met for one or more areas.</key>
+    <key alias="invalidMediaType">The chosen media type is invalid.</key>
+    <key alias="multipleMediaNotAllowed">Multiple selected media is not allowed.</key>
+    <key alias="invalidStartNode">The selected media is from the wrong folder.</key>
   </area>
   <area alias="healthcheck">
     <!-- The following keys get these tokens passed in:

src/Umbraco.Core/PropertyEditors/Validation/ITypedJsonValidator.cs

@@ -0,0 +1,19 @@
+using System.ComponentModel.DataAnnotations;
+using Umbraco.Cms.Core.Models.Validation;
+
+namespace Umbraco.Cms.Core.PropertyEditors.Validation;
+
+/// <summary>
+/// A specific validator used for JSON based value editors, to avoid doing multiple deserialization.
+/// <remarks>Is used together with <see cref="TypedJsonValidatorRunner{TValue,TConfiguration}"/></remarks>
+/// </summary>
+/// <typeparam name="TValue">The type of the value consumed by the validator.</typeparam>
+/// <typeparam name="TConfiguration">The type of the configuration consumed by validator.</typeparam>
+public interface ITypedJsonValidator<TValue, TConfiguration>
+{
+    public abstract IEnumerable<ValidationResult> Validate(
+        TValue? value,
+        TConfiguration? configuration,
+        string? valueType,
+        PropertyValidationContext validationContext);
+}

src/Umbraco.Core/PropertyEditors/Validation/TypedJsonValidatorRunner.cs

@@ -0,0 +1,51 @@
+using System.ComponentModel.DataAnnotations;
+using Umbraco.Cms.Core.Models.Validation;
+using Umbraco.Cms.Core.Serialization;
+
+namespace Umbraco.Cms.Core.PropertyEditors.Validation;
+
+/// <summary>
+/// <para>
+/// An aggregate validator for JSON based value editors, to avoid doing multiple deserialization.
+/// </para>
+/// <para>
+/// Will deserialize once, and cast the configuration once, and pass those values to each <see cref="ITypedJsonValidator{TValue,TConfiguration}"/>, aggregating the results.
+/// </para>
+/// </summary>
+/// <typeparam name="TValue">The type of the expected value.</typeparam>
+/// <typeparam name="TConfiguration">The type of the expected configuration</typeparam>
+public class TypedJsonValidatorRunner<TValue, TConfiguration> : IValueValidator
+    where TValue : class
+{
+    private readonly IJsonSerializer _jsonSerializer;
+    private readonly ITypedJsonValidator<TValue, TConfiguration>[] _validators;
+
+    public TypedJsonValidatorRunner(IJsonSerializer jsonSerializer, params ITypedJsonValidator<TValue, TConfiguration>[] validators)
+    {
+        _jsonSerializer = jsonSerializer;
+        _validators = validators;
+    }
+
+    public IEnumerable<ValidationResult> Validate(object? value, string? valueType, object? dataTypeConfiguration,
+        PropertyValidationContext validationContext)
+    {
+        var validationResults = new List<ValidationResult>();
+
+        if (dataTypeConfiguration is not TConfiguration configuration)
+        {
+            return validationResults;
+        }
+
+        if (value is null || _jsonSerializer.TryDeserialize(value, out TValue? deserializedValue) is false)
+        {
+            return validationResults;
+        }
+
+        foreach (ITypedJsonValidator<TValue, TConfiguration> validator in _validators)
+        {
+            validationResults.AddRange(validator.Validate(deserializedValue, configuration, valueType, validationContext));
+        }
+
+        return validationResults;
+    }
+}