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What is a JSON Action?

 JSON actions process JSON data, and convert it into specific data objects that can be used by PhixFlow for processing. The JSON action extracts one or more records from the provided JSON object using the JSON path specified.   

Creating JSON Actions

  1. Click and drag the  JSON icon from the toolbar onto the canvas
  2. Enter a name for the JSON action, then select Create Action
  3. In the JSON action  Properties on the right, populate the following details:
FieldDescriptionExample Value
NameName given to the JSON 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 a HTTP Node.

In PhixFlow version 11.1 onwards, this field is mandatory.

// Consists of the name of the connector and mapped attribute

in.body

Use Strict JSON parsing

Defines the parsing of the JSON. Disabled is lenient and enabled is 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

Path

The JSON Path expression is evaluated against the data provided by the Input Expression and returns a list of JSON elements. It determines which elements are extracted from the JSON.

The path starts at the root element represented by $ and each element in the path is separated by a full stop. The ^ traverses up a node and a . traverses down the node.

Note that the path determines the number of nodes that are processed, which directly correlates to the number of records returned by the JSON action. For example, if the path returns the root element of the JSON, only one record will be returned. Whereas a path that returns children nodes will return one record for each child element.

// JSON Path

$.main_page.title

Use literal values or expressions encapsulated within ${} syntax, for example ${in.MyValue}.

4.  Apply and Close all settings

Path Syntax

Expression Description

$ 

symbol refers to the root element.
@symbol refers to the current element.
. is the dot-child operator, which is used to denote a child element of the current element.
[ ] is used to select a child element of the current element (by name or index number).
*a wildcard, returning all elements regardless of their name.
^symbol is used to traverse up 1 element in the JSON hierarchy from child to parent. 

Output Attributes

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

Worked Example

This example is taken from 2.13 HTTP Action Configuration. If you have already completed this chapter as part of the Actionflow course, ensure you are familiar with the content before moving onto the next chapter.



FieldDescriptionExample Value
NameName given to the HTTP Node. This will be displayed on the Actionflow canvas.BankHolidays
HTTP MethodThe HTTP method. A drop-down field containing: GET, POST, GET or POST, HEAD, PUT, DELETE, other. If other is specified a text box will allow the entering of a custom value which is not empty and contains only uppercase letters.Get
URL Template

A template that computes the URL of the request.

Expects literal values or expressions encapsulated within ${} syntax, for example ${in.MyValue}.

https://www.gov.uk/bank-holidays.json
Body Template

Optional.

If this is provided then it is used to carry the HTTP request data. If a body is provided then usually Content-Type and Content-Length headers lines specify the nature of the body associated.

In PhixFlow if this evaluates to whitespace only then it is not included in the request.

The body expects literal values, or expressions encapsulated within ${} syntax, for example ${in.MyValue}.

//JSON Example
[{
    "Industry": "${in.Industry}"
}]
Error Expression

Optional.

A JEP expression to determine if the response is an error and if so, send on the Error Output Connection Point. The expression will have access to the input record (in) and the mapped output response (_result).

_result.isError
Log Traffic

Toggle on  to log the response of the HTTP request, e.g. see an error returned, or see the output before specifying a path.

Maximum HTTP Log Length

Available if Log Traffic is toggled on .

Restricts the size of the log traffic.

1000
Use Raw URL

Toggle on  to send the URL Template value in exactly the format it is provided to the HTTP Node.

If toggled off PhixFlow will transpose values to form a valid URL, such as replacing spaces with %20.

HTTP ConfigurationSee HTTP Configuration


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