What are Loop Actions?
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actions repeat an action or set of actions multiple times for a recordset or array.Loop Types
In PhixFlow, there are three types of supported looping:
Polling
Repeats the same operation multiple times with the same parameters, until a desired result is obtained.
- Generates a single output record
- Output results are only generated at the end of the iterations
- Example: polling a HTTP API until the results are available
Accumulation
Repeats 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
- Example: calling a database (DB) to get a parent record, and then repeating the call with the parent until the root has been reached
Paging
Repeats an operation multiple times with different parameters.
- Generates the next parameters with a set of output records for each iteration of the loop
- Example: reading from a paging API, where each iteration provides the link for the next iteration and a
Loop Action?Image Removed
The Start Loop and End Loop
Loops consist of a
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action updates reCreating Bulk Update Actions
Click ,joined by a loop connector which returns the result of the End node back to the Start node. The Start and End Loop each have their own properties.
On the
bulkupdatebulkupdate icon in the toolbar to display any existing tables in the applicationExisting tables can be dragged from the Repository onto the canvas, then choose , the Records to output can be set, either outputting All Records from the loop or just the Final Record. The icon on the end loop node shows which option is set.Image Added
Loop Mappings
Attributes passed into a loop are available as passthrough, as well as attributes mapped in from the End Loop. This allows the original passthrough values to be referenced and if the loop is manipulating the incoming attributes, for example, incrementing a number, this is also available.
The mapped attributes that are manipulated by the loop are shown with a loop icon on the Mappings window, and passthrough attributes are shown with the icon of where they have come from, for example, a
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Loops wait until all their internal nodes have completed their tasks before beginning the next iteration of the loop. |
Creating Loop Actions
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hidden | true- Click and drag the bulkupdatebulkupdate icon from the toolbar onto the canvas
- In the Create Bulk Update ActionLoop Action window:
- Enter a Name
- Choose to Allow Audited Table to display tables with Audit Manual Changes enabled in the Table drop down
- By default, tables with Audit Manual Changes enabled are not shown in the Table drop down list
- Choose the Table from the drop down where the records will be updated
- Or click the table icon to display tables in the Repository
- Select Create Action
When creating update actions it can be useful to set up confirmation messages that allow users to confirm or cancel the update. See 1.13 Confirmation Message Configuration.
- Select Create Action
- Map attributes from other actions to the
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to be processed by the loop - On the
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, set:- Records to output: Choose whether to output all records from the loop or just the final record
- Until Expression: An expression that is checked on each cycle of the loop, and once the expression returns true, the loop will end
- Example:
in.myValue == 10
- Max Loops: This is a safety net designed to stop infinite loops. After the number of loops set here, the loops will stop
- Set a sensible number of max loops
- This default to 10000
Worked Example
Here's a worked example using the Company Data (available from the Learning Centre).
In this example, we are using:
- A Company Management screen containing a grid of the Companies data and a card container of their associated Employees - this screen was created using the Multi-Tile templateA Company Merger Pop up screen containing:
- two manual drop down fields of the company name's of the companies to be merged
- two string fields showing the company ID's of the companies to be merged
a button to initiate the Actionflow Bank Holiday API - Loops screen containing a grid backed by an empty Bank_Holiday_Results table, drop down fields for the user to select the Year From and Year To values and a Run button - this screen was created using the Tile no Buttons templateA Company Orders screen containing two grids of the Orders and OrderLines data - this screen was created using the Multi-Tile template
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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 Advanced Application. For this example, we'll be working on the Company ManagementBank Holiday API - Loops screen. |
Bulk Update Employees and Orders for Company AcquisitionLoop Through Selected Years and Return Bank Holidays
In this example, a company is being merged into another company and we need to update the employees and orders to reflect the change.
GIF
Actionflow Setup
- Open the Company Management screen
- Click the Merge button to open the Company Merger Pop up screen
- Create an Actionflow on the Run Acquisition button
- Name:
RunCompanyAcquisition
- On the Actionflow canvas,
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Testing
- Close all screens and reopen the Company Management screen
- Choose two companies to merge and make a note of their employees so you can see if the merge is successful
- Open the Company Orders screen and make a note of any Orders and Order Lines for the two companies
- On the Company Management screen, click the Merge button to open the Company Merger Pop up screen
- Select the two companies to merge and click the Run Acquisition button
- Review the screens to check the merge was successful
3.05 Custom Confirmation Message Configurationuser selects a date range (years) to return UK bank holidays. We'll create an Actionflow that takes in these parameters and each cycle of the loop returns the bank holiday dates for that year. For the purposes of this example, our Actionflow will call an API that exists within PhixFlow but this API represents an external public API. This is an example of paging where you retrieve a set amount of data per request, this is particular useful for large datasets.
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Obtain the API URL
We have provided an Actionflow that acts as a UK Bank Holiday API. This can be called by a Actionflow, in the same way that an external API can be called. The UK Bank Holiday API has been configured to receive a year parameter and use that parameter to pass out the bank holiday dates for the corresponding year.
See 3.11 Setting up an API Endpoint for more details on how this API has been setup or to set one up yourself.
This is a copy of the JSON body response, which will help with understanding the syntax used for the Output Attributes on the JSON action, when calling the API.
- Search for the Bank Holiday API in the API Endpoint section of the
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for your application- Image Added
- Right-click the Bank Holiday API and select Edit
- Copy the URL and save it locally to be used later
This is a copy of the JSON body response, which will help with understanding the syntax used for the Output Attributes on the JSON action, when calling the API.
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title | JSON API Body Response |
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{
"getBH" : [ {
"UID" : "20190101e",
"Name" : "New Year?s Day",
"Date" : "2019-01-01T00:00:00.000Z",
"Country" : "england-and-wales"
}, {
"UID" : "20190419e",
"Name" : "Good Friday",
"Date" : "2019-04-19T00:00:00.000Z",
"Country" : "england-and-wales"
}, {
"UID" : "20190422e",
"Name" : "Easter Monday",
"Date" : "2019-04-22T00:00:00.000Z",
"Country" : "england-and-wales"
}, {
"UID" : "20190506e",
"Name" : "Early May bank holiday",
"Date" : "2019-05-06T00:00:00.000Z",
"Country" : "england-and-wales"
}, {
"UID" : "20190527e",
"Name" : "Spring bank holiday",
"Date" : "2019-05-27T00:00:00.000Z",
"Country" : "england-and-wales"
}, {
"UID" : "20190826e",
"Name" : "Summer bank holiday",
"Date" : "2019-08-26T00:00:00.000Z",
"Country" : "england-and-wales"
}, |
Actionflow Setup
Create an Actionflow using a
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to poll the API and retrieve the bank holidays for the years selected on the Company Bank Holidays API - Loops screen.- Open the Company Bank Holidays API - Loops screen
- Add an Actionflow to the Run button
- Name:
Get Bank Holidays
- Choose the input of the CompanyBankHolidayAPI-Loops form
- Map in the two input fields:
- YearFrom
- YearTo
- On the Mappings window, change the names of these two attributes on the input to allow them to be easily distinguished from two attributes with similar names we will create in the next section
- Change their names to:
- YearFromIn
- YearToIn
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Type Conversion
The data coming into the Actionflow from the screen is in the Type: String. Our Actionflow needs this data in Integer format. This can be changed on the field on the screen but can also be modified in the Actionflow, which we will do here.
- Create a
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action- Name:
ConvertToInteger
- Map both attributes from the input to the Calculate action
Use the function toNumber to create two Output Attributes on the Calculate action that convert the strings to integers
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Loop Action
- Create a
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action- Name:
Loop Years
- Connect the
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- Map across the YearFrom attribute
HTTP Action
- Create a
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to call the Bank Holiday API- Name:
Call BH API
- Connect the Start Loop action to the HTTP action
- Map across the YearFrom attribute from the
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to the HTTP action- Rename this attribute on the HTTP action to CallingYear
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- In the HTTP Action properties, enter the following:
- HTTP Method:
POST
- URL: Paste in the URL you copied earlier
Body:
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[{
"CallingYear": "${in.CallingYear}"
}] |
Toggle on Log Traffic to log the response from the API in the
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JSON Action
Create a JSON action to read the data coming in from the API.
- Create a
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to process the returned bank holiday data from the API- Name:
Returned Bank Holidays
- Connect the HTTP action to the JSON action using the out connector
- Map across the body from the HTTP action
Setup the JSON action to receive the data from the API
- Input Expression:
in.body
- Path:
$.getBH
- Output Attributes:
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title | Name: Name, Type: String |
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_result.Name |
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title | Name: UID, Type: String |
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_result.UID |
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title | Name: Country, Type: String |
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_result.Country |
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substring(_result.Date,1,10) |
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Save Action
Create a save action to save the bank holiday data to the Bank_Holiday_Results table where it can be viewed on the screen.
- Create a
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action to save the data- Name:
SaveBHs
- Type:
Auto Insert/Update
- Table: choose the Bank_Holiday_Results table
- This table has been prepopulated with the attributes required to hold the data
- Click Create Action
- Connect the JSON action to the Save action and map across the attributes being returned by the JSON action
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Increment Year By One
After the bank holiday data has been saved, we need the loop to go round again, this time getting the next year in the sequence, for example, if the user has entered 2018 for the YearFrom and 2020 for the YearTo, when the data is first saved, it is just the 2018 data. For the second loop, the 2019 data will be obtained, and so on. The criteria to end the loop is covered in the next section.
- Create a
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action- Name:
Increment +1
- Connect it to the Save action and map across the YearFrom attribute
- Ensure this is the attribute from the
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- On the Calculate action, add an Output Attribute:
- Name:
LoopYear
- Type:
Integer
- Expression:
in.YearFrom + 1
End Loop Setup
As the loop completes each iteration, criteria can be set on the End Loop to specify when the loop stops. This is specified using the Until Expression or Max Loops (whichever comes first). Our loop obtains one year's bank holidays for each loop, so if 2018 is entered for YearFrom and 2020 for YearTo, three loops are completed.
We want the looping to stop once the YearTo has passed, for this reason we must specify that the loop ends when the year after the YearTo has been reached.
- Connect the Increment +1
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- Map across the LoopYear attribute from the Increment +1
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- Setup the
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as follows:- Records to output:
All records
- This will output all the bank holidays, not just those satisfying the final year in the date range
- Until Expression:
in.LoopYear == in.YearTo+1
- Max Loops:
10
- A loop will be completed per year in the date range
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- On the Loop connector between the
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map the LoopYear attribute from the Insert excerpt |
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action to the YearFrom attribute - Image Added
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Testing
- Close all screens and reopen the Company Bank Holidays API - Loops screen
- Select the Year From and Year To criteria and press Run
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| 3.11 Setting up an API Endpoint |
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