Pick Operator

Overview

When working with a Data Workflow, you might need to retrieve an entire column from your data set. For this, you'll use a Pick operator.

Like a Get operator, the Pick operator uses a data reference key to find specific data in a large data set. Here, though, all you'll need is the label of the column you're looking for. Let's say you have a column with the key name in your data table. You want to bring that column into your Data Workflow. To do that, you'll use a Pick operator with name as the reference key.

You'll find the Pick operator under the Table group to the left of your canvas.

What You'll Learn

In this article, you'll learn:

About the Info Window

Here's what the operator looks like, along with its Info window:

And here's a breakdown of each setting in the Info window:

Setting

Description

Label

Sets the label for your operator. The label you enter here shows beneath your operator on your Data Workflow canvas.

This field is optional, but set a label if you use more than one of the same operator type. A label helps you identify your operators without opening any Info windows.

Pick Keys

This is the reference key leading to the data you want to retrieve. Here, you'll enter the key for the column you want your Pick operator to pull into your Data Workflow. So, if your column has the key name, you'll enter name here. If you're using another operator as an argument, enter _arg here.

Keys are case sensitive and must match the capitalization of your column key.

Adding a Pick Operator

To see a Pick operator in action, let's look at an example. You'll create a Data Table that holds a list of countries. In the Data Table, you'll include each country's capital. Then, you'll set up a Data Workflow with 2 Pick operators. Each operator will pull a separate column and put it in a Hidden component.

Here's how the completed use case will look in the Module Builder:

Here's how the completed use case will work in Express View, including a peek at the DevTools Console:

What You'll Need

To set up this use case, you’ll need:

  • 1 Data Table component

  • 2 Hidden components

  • 1 Data Workflow component

To set up your Data Workflow, you'll need:

  • 1 Input operator

  • 2 Pick operators

  • 2 Output operators

Configure the Data Table Component

First, you'll set up your Data Table.

1. Drag and drop a Data Table component onto your canvas.
2. Enter dtCountries in the Label and Property Name.
3. In the Data Table, enter the following:

A

B

country

capital

Afghanistan

Kabul

Albania

Tirana

Algeria

Algiers

Cambodia

Phnom Penh

Czechia

Prague

Andorra

Andorra la Vella

Austria

Vienna

4. Click Save.

Configure the Hidden Components

Before you can add your Data Workflow, you'll need a place to store its outputs. You'll use 2 Hidden components for that. Each Hidden component corresponds to its own Pick operator.

1. Drag and drop 2 Hidden components onto your canvas. Place your Hidden components below your Data Table.
2. Enter the following Property IDs and Label Text:

Property ID

Label Text

pickCountry

pickCountry

pickCapital

pickCapital
3. Save each component as you add it.

Configure the Data Workflow Component

1. Drag and drop a Data Workflow component onto your canvas. Place your Data Workflow above your Hidden components.
2. Enter dwfPick in the Label and Property Name.

Configure the Input Data Operator

1. Drag and drop an Input operator onto your Data Workflow canvas.
2. Configure the Input operator's Info window as follows:

Setting

Value

Category

Input

Component

dtCountries

Required

Yes

Source

Default

Configure the First Pick Operator

1. Drag and drop a Pick operator onto your Data Workflow canvas.
2. Configure the Pick operator's Info window as follows:

Setting

Value

Category

Pick

Label

Pick Country

Pick Keys

country
3. Connect the output port (right) of the Input operator to the input port (left) of the Pick Country Pick operator.

Configure the First Output Operator

1. Drag and drop an Output operator onto your Data Workflow canvas.
2. Configure the Output operator's Info window as follows:

Setting

Value

Category

Output

Component

pickCountry

Action

value
3. Connect the output port (right) of the Pick Country Pick operator to the input port (left) of the pickCountry Output operator.

Configure the Second Pick Operator

1. Drag and drop a second Pick operator onto your Data Workflow canvas.
2. Configure the Pick operator's Info window as follows:

Setting

Value

Category

Pick

Label

Pick Capital

Pick Keys

capital
3. Connect the output port (right) of the Input operator to the input port (left) of the Pick Capital Pick operator.

Configure the Second Output Operator

1. Drag and drop a second Output operator onto your Data Workflow canvas.
2. Configure the Output operator's Info window as follows:

Setting

Value

Category

Output

Component

pickCapital

Action

value
3. Connect the output port (right) of the Pick Capital Pick operator to the input port (left) of the pickCapital Output operator.
4. Click Save.
5. Save your module.

Now it's time to test your Data Workflow! Preview your module in Express View and then open the Console. You'll see your Hidden components now hold one column each: your list of countries and your list of capitals.

Changing a Pick Operator's Settings

You can revisit and make changes to this operator.

1. Click the Data Workflow component.

A 5-button toolbar displays above the component on hover-over.

2. Click the (Settings) button to open the Data Workflow canvas.
3. Click the operator to open its Info Window.
4. Make changes to the operator's settings as needed.
5. Click Save.
6. Save your module.

Copying a Pick Operator

You can make a copy of your operator using familiar keyboard settings. You can copy and paste an exact copy of your operator, matching all settings.

1. Hover over the Data Workflow component.

A 5-button toolbar displays above the component on hover-over.

2. Click the (Settings) button to open the Data Workflow canvas.
3. Click the operator you want to duplicate.
4. On your keyboard, press Command + C (Mac OS) or Ctrl + C (Windows/Linux) to copy the operator.

You can copy more than one operator at a time. Hold Command or Ctrl on your keyboard and click all the operators you want to copy. Follow the rest of the steps as usual.

5. On your keyboard, press Command + V (Mac OS) or Ctrl + V (Windows/Linux) to paste the copied operator(s) to the Data Workflow canvas.
6. Click Save.
7. Save your module.

Did you know you can copy an operator and paste it into a different Data Workflow? You'll use the same steps outlined above.

Removing a Pick Operator

Lastly, you can delete this operator from your Data Workflow canvas. You can also use these same steps to delete a connection between two operators.

1. Hover over the Data Workflow component.

A 5-button toolbar displays above the component on hover-over.

2. Click the (Settings) button to open the Data Workflow canvas.
3. Click the operator you want to delete.
4. On your keyboard, press Delete.

Once you delete this operator, make sure to connect your remaining operators. If your Data Workflow path doesn't end with an Output or Console operator, your Data Workflow won't work. So, once you delete an operator, make sure to update any remaining paths to end at an Output or Console operator.

5. Click Save.
6. Save your module.

Lab

You can view this complete use case here: https://training.unqork.io/#/form/5f4fdc911959bf0217f5471b/edit.