How to use data.Params["paramKey"] in Step Input expression?

[mciprijanovic]

Hello,

I have use case to set Input value of the wait step as an expression which will take certain value from the dictionary which is a property of my Data context object. I can manage to put expression and to extract value from dictionary only if the key is int or char, or anything that is not string. If I try to put string key parser complains and exception is thrown. Question is: can I use strings within expressions since all escaping options didn't work? I load definitions by using json since my definitions come from user and are dynamic, so fluent api doesn't fit. Here are simple examples:

This one works:
string json = @" { ""Id"": ""PocWorkflow"", ""Version"": 1, ""DataType"": ""WorkflowCorePOC.WorkflowDataContext, WorkflowCorePOC"", ""Steps"": [ { ""Id"": ""form-step"", ""Name"": ""form-step"", ""StepType"": ""WorkflowCorePOC.Steps.FormStep, WorkflowCorePOC"", ""NextStepId"": ""wait-form"", ""Inputs"": { ""FormName"": ""data.FormName"" } }, { ""Id"": ""wait-form"", ""Name"": ""wait-form"", ""StepType"": ""WorkflowCore.Primitives.WaitFor, WorkflowCore"", ""NextStepId"": ""decide-step"", ""Inputs"": { ""EventName"": ""\""FormFilled\"""", ""EventKey"": ""data.Keys[1]"" }, ""Outputs"": { ""EquipmentId"": ""step.EventData.EquipmentId"", ""FormOK"": ""step.EventData.FormOK"" } }, ......... ] }";

but this one doesn't work:
string json = @" { ""Id"": ""PocWorkflow"", ""Version"": 1, ""DataType"": ""WorkflowCorePOC.WorkflowDataContext, WorkflowCorePOC"", ""Steps"": [ { ""Id"": ""form-step"", ""Name"": ""form-step"", ""StepType"": ""WorkflowCorePOC.Steps.FormStep, WorkflowCorePOC"", ""NextStepId"": ""wait-form"", ""Inputs"": { ""FormName"": ""data.FormName"" } }, { ""Id"": ""wait-form"", ""Name"": ""wait-form"", ""StepType"": ""WorkflowCore.Primitives.WaitFor, WorkflowCore"", ""NextStepId"": ""decide-step"", ""Inputs"": { ""EventName"": ""\""FormFilled\"""", ""EventKey"": ""data.Keys[""someKey""]"" }, ""Outputs"": { ""EquipmentId"": ""step.EventData.EquipmentId"", ""FormOK"": ""step.EventData.FormOK"" } }, ......... ] }";

If someone can unblock me, I would really appreciate...

[mciprijanovic]

My bad. I should put \ in json so it knows that " is escaped.