Expression Builder

Overview

The Expression Builder is a valuable tool used to assist in the creation and examination of expressions. It essentially incorporates all of the elements required to create a properly formatted expression for use in any step of an Automate Desktop task. In programming, an expression is a combination of variables, constants, functions, and operators used to represent a particular value. For example, 2+3 is an arithmetic and programming expression that evaluates to 5. Many actions or operations that one might want to perform with expressions are already contained in Automate Desktop list of available actions. However, expressions can be used to further expand the capabilities of an action, thus, supplying more intelligence to the task as a whole due to its ability to resolve dynamic data during task execution.

Related Topics

ClosedAccessing the Expression Builder

The Expression Builder interface can be accessed from the Task Builder in the following ways:

  • In the properties of any activity, reering inside any text box that accepts an expression allows the Insert Expression/Variable button (represented by the % symbol) to appear to the right of the box. Clicking this button (or pressing F2 on your keyboard) causes the Expression Builder interface to be displayed.
  • From the Task Builder ribbon, select File > Tools > Expression Builder.

ClosedSections of the Expression Builder

The Expression Builder interface is arranged in sections as illustrated above. Each section plays an important role in the creation of an Automate Desktop expression.

Name Return Value
Folders panel Comprised of folders containing all available functions, extended functions, variables, datasets, and so on. This also includes the Insert Variable and Insert Array icons that enable creation of variables and arrays directly from the Expression Builder interface. The folders panel provides a hierarchical view of the following items. For more information on an item, click the associated link:
    • BASIC Functions - A library of BASIC VBA-compatible functions.
    • Extended Functions - A library of additional functions that extend the functionality of the Automate Desktop scripting engine beyond the capabilities that the basic VBA-compatible engine provides.
    • Datasets - Displays a list of available datasets.
    • Local Variables - Lists all local variables.
    • Task Variables - Lists all task variables.
    • AMError - Lists all AMError dataset names that can be used to examine properties of a specific error to determine task failure.
    • AMTrigger - Lists all AMTrigger dataset names that returns information about the trigger that started the task.
Contents panel Displays the contents of a folder selected from the Folders panel. Help for each content can be found by selecting the desired content from this Contents panel and pressing F1 on your keyboard.
Operators

Displays available operators that are symbols that represent specific actions or enables manipulation of numbers and text in more sophisticated ways. Operators can be used to construct more complex expressions.
Expression panel Displays the built expression. When double-clicking an item from the Contents panel, the expression is displayed in the Expression panel. Help can also be found for a function from this panel by placing the insertion cursor inside a function name and pressing F1 on your keyboard.
Search filter Searches entries for specified keywords and returns a list of the items where the keywords are found.

ClosedBuilding expressions

The Expression Builder can be used to construct expressions that you can use in the steps of your task.

To construct an expression

  1. Open the Expression Builder from an action dialog by clicking Insert Expression/Variable .

  2. Add elements to your expression by doing the following:

    • Select a folder from the left pane to reveal its contents in the right pane.

    • Double-click elements in the right pane to add them to your expression.

    • Select and replace characters in the expression as needed.

    • Select operators below the expression pane to add them to the expression.

  3. Click Insert to insert it into the specified action properties. When the expression is added to the action parameter, the percent signs (%) are automatically added to the beginning and end of the expression.

ClosedViewing expressions

The Expression Builder can be used to view specific objects that are created as a result of specific events. The Variables folder located in the Folders pane of the Expression Builder becomes populated if a Create Variable action is used to create the specified variables in an earlier step. Additionally, the datasets folder becomes populated when the specified datasets are initially created by running the step that creates and populates a dataset names and its contents, however, the dataset name itself is available in the Expression Builder if a step that creates the dataset appears in the task.

For example, imagine creating a task that includes a Get Email action as the first step to retrieve email messages from a POP3 mail box. The General tab of this action contains a parameter labeled Create and populate dataset that specifies the name of the dataset created and populated with the mail message upon execution.