To design and implement effective workflows in Circuit, you should understand how Circuit processes input and output as the data passes through its States.

When an execution is initiated, the input to the Circuit is provided as key value pairs in JSON format and then it is passed to the first state of the Circuit. Each state receives JSON as input and passes the output mostly in JSON format.

Input and output data can be filtered, controlled and manipulated using the below fields when the data flows from one state to another.

• Input Path

• Output Path

• Result path

• Parameters
  

Path 

In Circuit, Path is a string beginning with $ that identifies components within JSON text. Specific parts of a JSON can be accessed by denoting their attributes in Input Path, Output Path, and Result Path.  

Input Path    

Input path allows you to filter and control the actual input passed to the state. You can select a portion of the JSON input and pass it to the state for processing. The received JSON input is filtered using JsonPath notation.

1. {
2. "User1":{
3. "Name" : "Angelina",
4. "Id" : "357",
5. "location" : "CA"
6. },
7. "User2":{
8.       "Name" : "Martin",
9.       "Id" : "543",
10.       "location" : "CA"
11.       }
12. }

1. {
2.   "Name" : "Martin",
3.   "Id" : "543",
4.   "location" : "CA"
5.   }

Parameters  

Parameters allow you to modify the input by inserting a collection of key-value pairs to the input. The values of Parameters can either be static or parts of the JSON input selected as a Path. 

1. {
2. "EmployeeDetails": {
3. "employee1": {
4. "Name": "Sam",
5. "empID": "127",
6. "location": "CA",
7. },
8. "employee2": {
9. "Name": "John",
10. "empID": "721",
11. "location": "LA",
12. }
13. }
14. }

1. "Parameters": {
2. "teamDetails":{
3. "member1": "$.EmployeeDetails.employee1.Name",
4. "member2": "$.EmployeeDetails.employee2.Name",
5. "TeamName": "Product Management"
6.  }
7. },

1. {
2. "teamDetails":{
3. "member1": "Sam",
4. "member2": "John",
5. "TeamName": "Product Management"
6. }
7. },  

Result Path     

Result Path allows you to manipulate the output of a state. In result path, you can define the output of a state as the state's input or the state's result or a combination of both. In other words, you can append the state's result to the JSON input provided to the state and modify it. You can then pass this modified JSON as the state's output to the next state for processing.

Result Path can be defined to generate an output for the following state types.

• Pass

• Parallel

• Batch

• Function

• Webhook

• Circuit 

By default, if Result Path is not defined, the output of the previous state will be completely passed as the input of the new state.

1. {
2.  "TicketName" : "AddNameFailure",
3. "TicketId" : "12",
4.  "Priority" : 2
5. }

1. "Resolve within 24 hours"

1. "resultPath" : "$.TimeLimit"

1. {
2. "TicketName" : "AddNameFailure",
3. "TicketId" : "12",
4. "Priority" : 2,
5. "TimeLimit" : "Resolve within 24 hours"
6. }

Output Path   

Output Path allows you to select a portion of the state's output and pass it to the next state for processing by removing the unwanted objects from JSON output. If Output Path is not specified, then the entire JSON node (determined by the state input, state result and Result Path) will be sent as the state output to the next state.

1. {
2. "EmployeeInfo": {
3. "empName":  "Angelina",
4. "empId": "357",
5. "DOB": "12Nov1990"
6. },
7. "AddedInfo": {
8. "Gender": "Female",
9. "location": "CA"
10. }
11. }