Fix liquid engine to handle JObject and JValue resolution

elsa-workflows · May 30, 2021 · d195dfc · d195dfc
1 parent a8f6cf3
commit d195dfc
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Showing 3 changed files with 65 additions and 26 deletions.
diff --git a/src/scripting/Elsa.Scripting.Liquid/Handlers/ConfigureLiquidEngine.cs b/src/scripting/Elsa.Scripting.Liquid/Handlers/ConfigureLiquidEngine.cs
@@ -1,5 +1,7 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Dynamic;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Elsa.Models;
@@ -27,38 +29,75 @@ public Task Handle(EvaluatingLiquidExpression notification, CancellationToken ca
         {
             var context = notification.TemplateContext;
             var options = context.Options;
+            var memberAccessStrategy = options.MemberAccessStrategy;
 
-            options.MemberAccessStrategy.Register<ExpandoObject>();
-            options.MemberAccessStrategy.Register<JObject>();
-            options.MemberAccessStrategy.Register<JValue>(o => o.Value);
-            options.MemberAccessStrategy.Register<LiquidActivityModel>();
-            options.MemberAccessStrategy.Register<LiquidPropertyAccessor, FluidValue>((x, name) => x.GetValueAsync(name));
-            options.MemberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("Input", x => ToFluidValue(x.Input, options));
-            options.MemberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("WorkflowInstanceId", x => ToFluidValue(x.WorkflowInstance.Id, options));
-            options.MemberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("CorrelationId", x => ToFluidValue(x.CorrelationId, options));
-            options.MemberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("WorkflowDefinitionId", x => ToFluidValue(x.WorkflowInstance.DefinitionId, options));
-            options.MemberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("WorkflowDefinitionVersion", x => ToFluidValue(x.WorkflowInstance.Version, options));
-            options.MemberAccessStrategy.Register<ActivityExecutionContext, LiquidPropertyAccessor>("Variables", x => new LiquidPropertyAccessor(name => ToFluidValue(x.WorkflowExecutionContext.GetMergedVariables(), name, options)));
-            options.MemberAccessStrategy.Register<ActivityExecutionContext, LiquidPropertyAccessor>("Activities", x => new LiquidPropertyAccessor(name => ToFluidValue(GetActivityModelAsync(x, name), options)!));
-            options.MemberAccessStrategy.Register<LiquidActivityModel, object?>("Output", GetActivityOutput);
-            options.MemberAccessStrategy.Register<LiquidObjectAccessor<object>, object>((x, name) => x.GetValueAsync(name));
-            options.MemberAccessStrategy.Register<ExpandoObject, object>((x, name) => ((IDictionary<string, object>) x)[name]);
-            options.MemberAccessStrategy.Register<JObject, object?>((source, name) => source[name]);
-            options.MemberAccessStrategy.Register<ActivityExecutionContext, LiquidPropertyAccessor>("Configuration", x => new LiquidPropertyAccessor(name => ToFluidValue(GetConfigurationValue(name), options)!));
-            options.MemberAccessStrategy.Register<ConfigurationSectionWrapper, ConfigurationSectionWrapper?>((source, name) => source.GetSection(name));
+            options.ValueConverters.Add(x => x is JObject o ? new ObjectValue(o) : null);
+            options.ValueConverters.Add(x => x is JValue v ? v.Value : null);
+
+            memberAccessStrategy.Register<ExpandoObject>();
+            memberAccessStrategy.Register<JObject>();
+            memberAccessStrategy.Register<JValue>(o => o.Value);
+            memberAccessStrategy.Register<LiquidActivityModel>();
+            memberAccessStrategy.Register<LiquidPropertyAccessor, FluidValue>((x, name) => x.GetValueAsync(name));
+            memberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("Input", x => ToFluidValue(x.Input, options));
+            memberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("WorkflowInstanceId", x => ToFluidValue(x.WorkflowInstance.Id, options));
+            memberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("CorrelationId", x => ToFluidValue(x.CorrelationId, options));
+            memberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("WorkflowDefinitionId", x => ToFluidValue(x.WorkflowInstance.DefinitionId, options));
+            memberAccessStrategy.Register<ActivityExecutionContext, FluidValue>("WorkflowDefinitionVersion", x => ToFluidValue(x.WorkflowInstance.Version, options));
+            memberAccessStrategy.Register<ActivityExecutionContext, LiquidPropertyAccessor>("Variables", x => new LiquidPropertyAccessor(name => ToFluidValue(x.WorkflowExecutionContext.GetMergedVariables(), name, options)));
+            memberAccessStrategy.Register<ActivityExecutionContext, LiquidPropertyAccessor>("Activities", x => new LiquidPropertyAccessor(name => ToFluidValue(GetActivityModelAsync(x, name), options)!));
+            memberAccessStrategy.Register<ActivityExecutionContext, LiquidActivityModel?>("InboundActivity", GetInboundActivityModelAsync);
+            memberAccessStrategy.Register<LiquidActivityModel, object?>(GetActivityProperty);
+            memberAccessStrategy.Register<LiquidObjectAccessor<JObject>, JObject>((x, name) => x.GetValueAsync(name));
+            memberAccessStrategy.Register<ExpandoObject, object>((x, name) => ((IDictionary<string, object>) x)[name]);
+            memberAccessStrategy.Register<JObject, object?>((source, name) => source.GetValue(name, StringComparison.OrdinalIgnoreCase));
+            memberAccessStrategy.Register<ActivityExecutionContext, LiquidPropertyAccessor>("Configuration", x => new LiquidPropertyAccessor(name => ToFluidValue(GetConfigurationValue(name), options)!));
+            memberAccessStrategy.Register<ConfigurationSectionWrapper, ConfigurationSectionWrapper?>((source, name) => source.GetSection(name));
 
             return Task.CompletedTask;
         }
 
         private ConfigurationSectionWrapper GetConfigurationValue(string name) => new(_configuration.GetSection(name));
         private Task<FluidValue> ToFluidValue(object? input, TemplateOptions options) => Task.FromResult(FluidValue.Create(input, options));
-        private Task<FluidValue?> ToFluidValue(Variables dictionary, string key, TemplateOptions options) => Task.FromResult(!dictionary.Has(key) ? default : FluidValue.Create(dictionary.Get(key), options));
-        private LiquidActivityModel GetActivityModelAsync(ActivityExecutionContext context, string name) => new(context, name);
+        private Task<FluidValue> ToFluidValue(Variables dictionary, string key, TemplateOptions options) => Task.FromResult(!dictionary.Has(key) ? NilValue.Instance : FluidValue.Create(dictionary.Get(key), options));
+        private LiquidActivityModel GetActivityModelAsync(ActivityExecutionContext context, string name) => new(context, name, null);
 
-        private Task<object?> GetActivityOutput(LiquidActivityModel activityModel)
+        private object? GetInboundActivityModelPropertyAsync(ActivityExecutionContext context, string propertyName)
         {
-            var output = activityModel.ActivityExecutionContext.GetOutputFrom(activityModel.ActivityName);
-            return Task.FromResult(output);
+            var activityModel = GetInboundActivityModelAsync(context);
+
+            if (activityModel == null)
+                return null;
+
+            return GetActivityProperty(activityModel, propertyName);
+        }
+
+        private LiquidActivityModel? GetInboundActivityModelAsync(ActivityExecutionContext context)
+        {
+            var inboundActivityId = context.WorkflowExecutionContext.GetInboundActivityPath(context.ActivityId).FirstOrDefault();
+
+            if (inboundActivityId == null)
+                return null;
+
+            return new LiquidActivityModel(context, null, inboundActivityId);
+        }
+
+        private object? GetActivityProperty(LiquidActivityModel activityModel, string name)
+        {
+            var activityExecutionContext = activityModel.ActivityExecutionContext;
+
+            // Deprecated.
+            if (name == "Output")
+            {
+                var output = activityExecutionContext.GetOutputFrom(activityModel.ActivityName!);
+                return output != null ? new JObject(output) : default;
+            }
+
+            var workflowExecutionContext = activityExecutionContext.WorkflowExecutionContext;
+            var activityId = activityModel.ActivityId ?? workflowExecutionContext.GetActivityBlueprintByName(activityModel.ActivityName!)!.Id;
+            var activityState = workflowExecutionContext.WorkflowInstance.ActivityData.GetItem(activityId, () => new JObject());
+            var value = activityState.GetState<object>(name);
+            return value;
         }
     }
 }
diff --git a/src/scripting/Elsa.Scripting.Liquid/Helpers/LiquidActivityModel.cs b/src/scripting/Elsa.Scripting.Liquid/Helpers/LiquidActivityModel.cs
@@ -2,7 +2,7 @@
 
 namespace Elsa.Scripting.Liquid.Helpers
 {
-    public record LiquidActivityModel(ActivityExecutionContext ActivityExecutionContext, string ActivityName)
+    public record LiquidActivityModel(ActivityExecutionContext ActivityExecutionContext, string? ActivityName, string? ActivityId)
     {
     }
 }
diff --git a/src/scripting/Elsa.Scripting.Liquid/Helpers/LiquidPropertyAccessor.cs b/src/scripting/Elsa.Scripting.Liquid/Helpers/LiquidPropertyAccessor.cs
@@ -12,7 +12,7 @@ namespace Elsa.Scripting.Liquid.Helpers
     /// </summary>
     public class LiquidPropertyAccessor : LiquidObjectAccessor<FluidValue>
     {
-        public LiquidPropertyAccessor(Func<string, Task<FluidValue?>> getter) : base(getter!)
+        public LiquidPropertyAccessor(Func<string, Task<FluidValue>> getter) : base(getter!)
         {
         }
     }