Understanding flow states

Zendesk Integration Services (ZIS) uses a JSON-based, structured language similar to Amazon States Language to define an integration. This language can define states in ZIS such as performing tasks, determining which states to transition to next, and stopping an execution with an error. A ZIS flow is made up of one or more states.

State types

ZIS supports the following state types:

• Action - Performs a task, such as transforming data or making a REST API call. See Action state
• Choice - Adds conditional branching to a flow. See Choice state
• Map - Enables looping or iterating over a set of input data. See Map state
• Wait - Pauses for the specified number of seconds before transitioning to the next state. See Wait state
• Succeed - Stops the flow in cases that are considered successful and passes a developer-defined message to the integration logs. Example: When a Choice state indicates no further action is required. See Succeed state
• Fail - Stops the flow in cases that are considered errors and passes a developer-defined message to the integration logs. Example: When a Choice state finds an invalid input value. See Fail state
• Pass - Passing a step's input to its output without doing any work. It can optionally add data to the output. Example: To mockup the result of a Choice or Action state for testing or debugging purposes. See Pass state

Common state properties

Most states support the following properties.

Name	Type	Mandatory	Description
Type	string	true	The state's type. For supported values, see State types. All states require Type
Next	string	Most state types require either Next or End	Next state to run in the ZIS flow. You can't use Next and End in the same state. The Fail and Succeed state types don't support Next. The Choice state type supports multiple Next properties
End	boolean	Most state types require either Next or End	If true, the state is terminal and ends the ZIS flow. A flow can contain multiple terminal states. End doesn't support a value of false. The Choice, Fail, and Succeed state types don't support End as they are implied terminal states
Comment	string	false	Human-readable comment
InputPath	string	false	JSONPath to a part of the state's input. The state can only access this part of the input. Defaults to "$", the entire input. The Action and Succeed state types don't support InputPath
ResultPath	string	false	Reference path used to the store the state's output. Later states of the ZIS flow can access the output at this path. The state's output is further filtered by OutputPath, if provided. Defaults to "$", which replaces the state's input with its output. The Choice, Fail, Succeed, and Wait state types don't support ResultPath
OutputPath	string	false	JSONPath to a part of the state's output. The state only passes this part of the output to the next state. Defaults to "$", the entire output. The Action and Succeed state types don't support OutputPath

For example, the following state includes the Comment, Type, ResultPath, and Next properties.

"SlackSettings.LoadConfig": {
    "Comment": "Loads the Slack channel and ticket priority settings",
    "Type": "Action",
    "ActionName": "zis:common:action:LoadConfig",
    "Parameters": {
      "scope": "slack_settings"
    },
    "ResultPath": "$.config_result",
    "Next": "NextState"
}

Accessing data in a state

ZIS flows have access to a top-level $ JSON object. The object contains data about the event that triggered the flow, the flow's integration, and the Zendesk account. Example:

{
  "account_id": 123456,
  "integration_key": "zis_example_integration",
  "subdomain": "acme",
  "input": {
    ...
  }
}

For more information about the $ object's schema, see the reference documentation.

Reference paths

Some state properties can access or modify the $ object using a reference path. A reference path is a JSONPath string that points to a single node of the $ object. The node must be a single value, an array, or an object.

Reference paths always start with $. To reference the entire $ object, use the $ reference path.

For example, the following Choice state's Variable property reads data from the $.subdomain reference path. When the state runs, ZIS replaces the path with its referenced value. In this case, the path's value is the Zendesk subdomain of the account running the ZIS flow.

"choice.checkSubdomain": {
  "Type": "Choice",
  "Choices": [
    {
      "Not": {
        "Variable": "$.subdomain",
        "StringEquals": "acme-production"
      },
      "Next": "ErrorStep"
    }
  ],
  "Default": "NextStep"
}

As another example, the following Pass state's ResultPath property writes data to the $.comment_id reference path, overwriting any existing data for the $ object's comment_id property.

"Pass.GetCommentId": {
  "Type": "Pass",
  "Result": {
      "commentId": "123456"
  },
  "ResultPath": "$.comment_id",
  "Next": "NextStep"
}

Path placeholders

Some state properties support a mix of static JSON and path placeholders. This lets you interpolate data from the $ object into the property's value.

To create a path placeholder, wrap a reference path in double curly brackets ({{ }}). When the state runs, ZIS replaces the placeholder with the reference path's value.

For example, the following Succeed state contains a Message property. The property contains a path placeholder for the integration's key.

"Logs.Succeeded": {
  "Type": "Succeed",
  "Message": "Message posted for integration: {{$.integration_key}}"
}

State limitations

The documentation for each state type includes known limitations and differences from the Amazon States Language. ZIS flows also have the following limitations:

• ZIS flows don't support the Parallel state type. ZIS flows don't support concurrent execution.

• ZIS flows don't support the Task state type. Use an Action state instead.

• ZIS flow states don't support intrinsic functions.

• ZIS flows have limited support for retries. See Flow states retry and error handling.