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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.

// 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 route 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.AttributeName.


Worked Example

Here is a worked example using the Shop Data (available from the Learning Centre).

In this example, we are using:  

  • A Shop Staff screen containing a grid of the Shop Staff data and a blank tile  - this screen was created using the Multi-Tile 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 blank tile on the Shop Staff screen.

GIF/SCREENSHOT OF FINISHED RESULT   

Calculate Working Days

In this example, we'll use the bank holiday data created in 2.12 HTTP Action Configuration to calculate the remaining working days in the current month and map this onto a screen. 

Table Setup

  1. Create a new  Table on your  ERD to save the working days data to, and ensure it contains the following attributes:
    1. Name: UID
      1. Type: Integer
      2. Expression: _NULL
    2. Name: Date
      1. Type: Date
      2. Expression: _NULL

Event Handler Setup

  1. On the Shop Staff screen, find the Working Days tile
  2.  Lock the screen to expand the tile
  3.  Unlock the screen and click on the chevron (True/False Field) to open its Properties 

  4. Create a new Actionflow on an Event Handler that will run when the chevron state is changed

  5. On the Actionflow, set the Input as On Change

Extract Actions From Actionflow

We will reuse the Actions created to retrieve the bank holiday dates.

 Prerequistites

If you have not completed the worked example in 2.12 HTTP Action Configuration, follow the steps to create the actions required for this chapter, excluding the Open Screen action.

  1. Open the Actionflow that retrieves bank holidays from the government website, created in 2.12 HTTP Action Configuration
  2. Hold down Ctrl and click on the  HTTP action, the  JSON action and the  Save action
  3. Right-click and choose  Extract to new Actionflow
    1. Name: Get Gov Bank Holidays

Working Days Actionflow

  1. Click back into the Calculate Working Days  Actionflow
  2. From the toolbar, click on  Actionflow to open the list of Actionflows in the repository
  3. Drag Get Gov Bank Holidays onto the canvas to create an embedded  Actionflow node
  4. Connect the  input to the embedded Actionflow node
  5. Add a  Calculate action to the canvas and connect it to the the embedded Actionflow node
  6. On the Calculate action, add an Output Attribute that works out the last day of the current month:
    1. Name: LastDay
    2. Type: String
    3. Order: 1

    4. Expression: 

      do( 
//set $lastDay to the 1st day of the month
    $lastDay = dateSet(now(),_DAY,1),
     
//add a month to $lastDay
        $lastDay = dateAdd($lastDay, _MONTH,1),
        
//minus a day to get the last day of the month
            $lastDay = dateAdd($lastDay, _DAY,-1)
                          
)
  7. Hover over the Calculate action to add a lookup 
  8. Create a   View action that retrieves the bank holiday data
  9. Set the Incoming and Outgoing Mappings:
    1. Incoming: LastDay
    2. Outgoing: Date

  10. Create a filter on the View that retrieves only bank holiday dates for England and Wales, and the current month

     How?

  11. On the Calculate action, add an Output Attribute that works out the working days:
    1. Name: CalculateWorkingDays
    2. Type: Structured Data
    3. Order: 2

    4. Expression: 

      do(

    //Get the last day of the month and set $lastDay to this
    $lastDay = dateGet($lastDay,_DAY),

        //for each day of the month, remove the time and set $allDays to now
        forEach($day,1..$lastDay,
 
            addElement($allDays, removeTime(dateSet(now(),_DAY,$day)
                                )
                        )
                ),

                    //remove BH days from month days
                    excluded($allDays, lu.Date)
)
  12. Hover over the Calculate action and select out, then create a  Save action to map the data to the Working Days table
  13. Map across the CalculateWorkingDays attribute from the Calculate action to the Date attribute on the Working Days table

Testing

  1. Test your Actionflow by clicking the chevron on the Shop Staff screen

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