Overview

Use a Loop Node when it is neccessary to repeat an action or set of actions multiple times.

There are three types of supported looping:

Polling, repeating the same operation multiple times with the same parameters until a desired result is obtained and then generating a single output record. Output results are only generated at the end of the iterations. For example, polling an HTTP API until the results are available.
Accumulation, repeating the same operation multiple times, where each iteration accumulates the progress results and triggers the next iteration with the updated result. Generates a single output record. For example, calling the DB to get the parent record, and repeating with the parent until the root has been reached.
Paging, repeating an operation multiple times with different parameters and generating the next parameters with a set of output records for each iteration of the loop. For example, reading from a paging API, where each iteration gives you the link for the next iteration, and a set of output records.

Properties Tab

Basic Settings

Field	Description	Example Value
Name	Name given to the action node. This will be displayed on the actionflow canvas.	MyJSONReader
Input Expression	The input expression provides the JSON data to be operated upon. Typically this will be a simple expression pointing at an incoming attribute such as the body from an HTTP Action or the body from an API request.	// consist of the name of the pipe and the name of a // mapped attribute. `in.body`
Use Strict JSON parsing	Defines the parsing of the JSON, disabled will be lenient and enabled will be strict. Lenient parsing relaxes validation allowing the following to be present in the JSON data: Use of single quotes, for example: {'name': 'Some “quotes” in a string'} Unquoted field names, for example: {name: “value”} Unescaped control characters, including literal new lines to appear within a string. Allow trailing commas {“name”: ”value”,}	// leaving the default option Disabled.
Path	The JSON Path expression is evaluated against the data provided by the Input Expression and returns a list of JSON node items. It can be used to specify which nodes are extracted from the JSON.	// JSON Path `$.main_page.title`

Input Connection Points

Can Accept a single Driving input connection point.

The grid contains a list of all input connection points and their type.

To add a new input connection point, in the section toolbar click Add New to open a new input connection point and set its properties; see Input Connection Points.
To edit an existing input connection point, double-click it in the list to open its properties.
To remove an input connection point, select one and in the section toolbar click Delete.

Output Connection Points

This section has a toolbar with standard buttons. The grid contains a list of all output connection points.

To add a new output path, in the section toolbar click Add New to open a new output path and set the expression; see Output Connection Points.
To edit an existing output path, double-click it in the list to open its properties.
To remove an output path, select one and in the section toolbar click Delete.

Output Attributes

JSON is converted into data objects that can be used by PhixFlow, this information is accessed using the syntax, _result.AttributeName.

Worked Example

Below is an example JSON object passed to the JSON Action Node:

Example JSON

// Example JSON string.
{
    "main_page": {
        "page": "PF Main Page",
        "title": {
            "name": "PF Title Text",
            "data": [
                {"initials": "AA", "value" : "Alistair Andrews"},
                {"initials": "BB", "value" : "Bert Brown"}
            ]
        }
    }
}

JSON Path: $.main_page.title

This path will bring back all elements matching the JSON path including the parent/grandparents and all child elements. The path defines the starting point from which we reference the JSON nodes.

The following examples show how to reference the returned JSON data:

_result.name, returns PF Title Text
_result.^.page, returns PF Main Page
1. The ^ traverses up the JSON hierarchy.
listToString(_result.data.initials), returns "AA, BB"
1. Because there are multiple JSON nodes under _result.data.initials, an array of data is returned. See Array Handling Functions.

Note the use of

^ traverses up the hierarchy 1 layer.
. tranverses down the heirach 1 layer.

Learn More

For links to all pages in this topic, see Understanding Actionflows.

Loop Action