2.14 JSON Action Configuration

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.


Here is a worked example using the Retail Data (available from the Learning Centre) and JSON data from the UK government website (https://www.gov.uk/bank-holidays.json).

In this example, we are using:  

  • Shop Shipping screen containing a grid of Orders data, a grid of Order Lines data, an area containing a Date form field and buttons  - this screen was created using the Multi-Tile template
  • A Shop Shipping Popup screen containing a grid of the bank holiday data  - this screen was created using the Tile no Buttons template

If you are completing this chapter as part of the Actionflow course and using a training instance, the data and screens have already been pre-loaded into the Actionflow Intermediate Application. For these example, we'll be working on the Search button on the Shop Shipping screen, and the Shop Shipping Popup screen

Identify Bank Holiday Dates

In this example, we'll create an Actionflow that retrieves bank holiday dates in the UK from the government website in JSON format and map this onto a screen in a grid. 

Table Setup

  1. Create a new  Table on your  ERD to save the bank holiday data to, and ensure it contains the following attributes:
    1. Name: UID
      1. Type: String
      2. Length: 50
      3. Expression: _NULL
    2. Name: Name
      1. Type: String
      2. Length: 200
      3. Expression: _NULL
    3. Name: Date
      1. Type: Date
        1. Leave the Expression field blank
    4. Name: Country
      1. Type: String
      2. Length: 50 
        1. Leave the Expression field blank

HTTP Action Setup

  1. On the Shop Shipping screen, add an Actionflow to the  ("GetDates") button 

  2. Select Click to Connect and choose On Click

  3. Drag a  HTTP action onto the canvas and give it a suitable name - this will be used to retrieve the bank holidays from the government JSON URL

  4. Drag the  input connection point node onto the HTTP action

  5. Click on the  HTTP action to open its Properties

    1. HTTP Method: GET
    2. URL: https://www.gov.uk/bank-holidays.json


  6. Drag a  JSON action onto the canvas and give it a suitable name - this will be used to convert the JSON data into data suitable for our bank holiday table
  7. Connect the out connector from the HTTP node to the JSON node
    1. Map across attribute, body

       Checkpoint


JSON Action Setup

  1. Click on the  JSON action to open its Properties
    1. Input Expression: in.body
    2. Path: $..events
    3. Output Attributes:

      Name: Country, Type: String
      _result.^.^.division


      Name: Date, Type: Date
      toDate(_result.date, "yyyy-MM-dd")
      Name: ID, Type: String
      toString(_result.date, "yyyyMMdd") + substring(_result.^.^.division, 1,1)
      Name: Title, Type: String
      _result.title
  2. Hover over the JSON action and select out
  3. Create a  Save action
    1. Primary Table: The Bank Holidays table you created earlier
    2. Map across the JSON attributes to their relevant attributes on the Save action
       How?

  4. Hover over the Save action and choose out
  5. Create an  Open Screen action to open the Shop Shipping Popup screen

     Checkpoint

Screen Setup

  1. Open the Shop Shipping Popup screen
  2. Click on  Attributes in the toolbar, then select the Bank Holidays table you created earlier
  3. In the Available Attributes selector, select all attributes and drag them onto the screen, then choose to display the data as a  Grid

Testing

  1. Close all open screens and reopen the Shop Shipping screen
  2. Click the  button to run the Actionflow
  3. If the Actionflow is working, the Shop Shipping Popup screen should open containing all of the bank holiday data from the government website

Background Filter and Default Sort Order

Tidy up your Shop Shipping Popup screen by hiding the UID column on the grid, adding a Default Filter to show only bank holidays in the future, and Default Sort Order to show the most recent bank holidays first.

 How?
  1. Right-click on the grid and choose,  Show the View Configuration
  2. In the Data Retrieval Options section of the Properties:
    1. For Background Filter, select the  icon to create a new background filter
    2. For Default Sort Order, select the  icon to create a new sort order