Dropdown Component

Function

a!dropdownField( label, labelPosition, instructions, required, disabled, choiceLabels, choiceValues, placeholder, value, validations, saveInto, validationGroup, requiredMessage, helpTooltip, accessibilityText, showWhen, searchDisplay )

Displays a list of choices for the user to select one item and saves a value based on the selected choice.

If the user may select none, one, or many of the choices, use either the checkbox component or a multiple dropdown component.

If there aren't many choices and users would benefit from easily seeing them all at once, consider using radio buttons.

Parameters

Name	Keyword	Types	Description
Label	label	Text	Text to display as the field label.
Label Position	labelPosition	Text	Determines where the label appears. Valid values: "ABOVE" (default) Displays the label above the component. "ADJACENT" Displays the label to the left of the component. "JUSTIFIED" Aligns the label alongside the component starting at the edge of the page. "COLLAPSED" Hides the label. The label will still be read by screen readers; see accessibility considerations for more information.
Instructions	instructions	Text	Supplemental text about this field.
Required	required	Boolean	Determines if a value is required to submit the form. Default: false.
Disabled	disabled	Boolean	Determines if the field should display as potentially editable but grayed out. Default: false.
Choice Labels	choiceLabels	List of Text String	Array of options for the user to select.
Choice Values	choiceValues	List of Variant	Array of values associated with the available choices.
Placeholder	placeholder	Text	Text to display when nothing is selected and the value is null.
Selected Value	value	Any Type	Value of the choice to display as selected.
Validations	validations	List of Text String	Validation errors to display below the field when the value is not null.
Save Selection To	saveInto	List of Save	One or more variables that are updated with the choice value when the user changes the selection. Use a!save() to save a modified or alternative value to a variable.
Validation Group	validationGroup	Text	When present, the requiredness of the field is only evaluated when a button in the same validation group is pressed. The value for this parameter cannot contain spaces. For example, “validation group” is not a valid value. You need to add an underscore between words: “validation_group”. See the following recipes for more information: Configure Buttons with Conditional Requiredness Validation Groups for Buttons with Multiple Validation Rules'
Required Message	requiredMessage	Text	Custom message to display when the field's value is required and not provided.
Help Tooltip	helpTooltip	Text	Displays a help icon with the specified text as a tooltip. The tooltip displays a maximum of 500 characters. The help icon does not show when the label position is "COLLAPSED".
Accessibility Text	accessibilityText	Text	Additional text to be announced by screen readers. Used only for accessibility; produces no visible change.
Visibility	showWhen	Boolean	Determines whether the component is displayed on the interface. When set to false, the component is hidden and is not evaluated. Default: true.
Search Display	searchDisplay	Text	Determines when a search box displays above the options. Valid values: "AUTO" (default), "ON", "OFF". When set to "AUTO", the search box displays if there are more than 11 options.

Usage considerations

Using the placeholder parameter

• To allow users on web to clear the selected value, text must be specified for the placeholder parameter. Users can always clear the value on the Appian for Mobile application.
• Passing a null value to the dropdown's Selected Value parameter causes the placeholder text to appear selected. The Placeholder and Selected Value parameter cannot both be null.

Using the choiceLabels and choiceValues parameters

• Options display in the same order as defined in the Choice Labels parameter. The Choice Labels parameter cannot be null.
• Choice Values cannot contain nulls or duplicate values.
• The Choice Labels list and Choice Values list must be the same length.

Dropdowns vs pickers

• If you are trying to decide whether to use a dropdown with search or a picker component, keep in mind that the dropdown search runs client-side and the performance cost of loading options happens on initial load whereas the picker search runs server-side and the performance cost of loading options happens while the user is searching. For small sets of options, we recommend using the dropdown component.

Examples

Click EXPRESSION to copy and paste an example into the Interface Definition to see it displayed.

Dropdown with the first choice selected by default and search on auto

Since the searchDisplay parameter is set to AUTO and the number of choiceValues is less than 12, no search box will be displayed.

Use the interactive editor below to test out your code:

Since the searchDisplay parameter is set to AUTO and the number of choiceValues is more than 11, a search box will be displayed.

Use the interactive editor below to test out your code:

Dropdown with no choice selected by default and search on

Since the searchDisplay parameter is set to ON, even though the number of choiceValues is less than 12, a search box will be displayed.

Use the interactive editor below to test out your code:

Feature compatibility

The table below lists this component's compatibility with various features in Appian.

Feature	Compatibility	Note
Portals	Compatible
Offline Mobile	Compatible
Sync-Time Custom Record Fields	Incompatible
Real-Time Custom Record Fields	Incompatible	Custom record fields that evaluate in real time must be configured using one or more Custom Field functions.
Process Reports	Incompatible	Cannot be used to configure a process report.
Process Events	Incompatible	Cannot be used to configure a process event node, such as a start event or timer event.

Old versions

There are older versions of this interface component. You can identify older versions by looking at the name to see if there is a version suffix. If you are using an old version, be sure to refer to the corresponding documentation from the list below.

Old Versions	Reason for Update
a!dropdownField_20r2	Added an optional search box and renamed the placeholderLabel parameter to placeholder.'

To learn more about how Appian handles this kind of versioning, see the Function and Component Versions page.

Related Patterns

The following patterns include usage of the Dropdown Component.

• Add Validations to an Inline Editable Grid (Validation, Grids, Looping): Allows the user to change data directly in a grid, and validate a various entries.

• Add, Edit, and Remove Data in an Inline Editable Grid (Grids, Looping): Allow the user to change data directly in an inline editable grid.

• Conditionally Hide a Column in a Grid (Grids, Conditional Display): Conditionally hide a column in a read-only grid when all data for that column is a specific value.

• Configure Buttons with Conditional Requiredness (Validation): Present two buttons to the end user and only make certain fields required if the user clicks a particular button

• Configure Cascading Dropdowns (Conditional Display, Choice Components): Show different dropdown options depending on the user selection.

• Configure a Dropdown Field to Save a CDT (Choice Components): When using a dropdown to select values from the database, or generally from an array of CDT values, configure it to save the entire CDT value rather than just a single field.

• Configure a Dropdown with an Extra Option for Other (Choice Components): Show a dropdown that has an "Other" option at the end of the list of choices. If the user selects "Other", show a required text field.

• Configure an Array Picker with a Show All Option (Pickers): Allow users to choose from a long text array using an autocompleting picker, but also allow them to see the entire choice set using a dropdown.

• Display Multiple Files in a Grid (Document Management, Grids): Show a dynamic number of files in a grid and edit certain file attributes.

• Document List (Documents): Use the document list items pattern to display a list of documents that can be searched and filtered. This pattern uses a combination of cards and rich text to show an easy to navigate list of documents of different types.

• Dynamically Show Sales by Product Category Compared to Total Sales (Records, Reports, Charts, Filtering): This pattern illustrates how to create an area chart that dynamically displays sales generated by product category compared to total sales.

• Filter the Data in a Grid (Grids, Filtering, Records): Configure a user filter for your read-only grid that uses a record type as the data source. When the user selects a value to filter by, update the grid to show the result.

• Save a User's Report Filters to a Data Store Entity (Grids, Smart Services, Filtering, Reports): Allow a user to save their preferred filter on a report and automatically load it when they revisit the report later.

• Searching on Multiple Columns (Grids, Filtering, Reports): Display a grid populated based on search criteria specified by end users.

• Track Adds and Deletes in Inline Editable Grid (Grids): In an inline editable grid, track the employees that are added for further processing in the next process steps.

• Update an Entity-Backed Record from its Summary View (Records, Smart Services): Enable users to make quick changes to a record by updating it right from a record view.

• Use Links in a Grid to Show More Details and Edit Data (Grids): Allow end users to click a link in a read-only grid to view the details for the row, and make changes to the data. The data available for editing may include more fields than are displayed in the grid.

• Use Selection For Bulk Actions in an Inline Editable Grid (Grids): Allow the user to edit data inline in a grid one field at a time, or in bulk using selection.

• Use Validation Groups for Buttons with Multiple Validation Rules (Validation): Present two buttons to the end user that, based on the selection, will validate only after a particular button is clicked.

• Use a Filter to Adjust Chart Reference Lines (Filtering, Charts): Using a dropdown, filter the results of a data set while also adjusting a chart reference line.

• Year-Over-Year Report (Charts, Reports, Formatting): This is a feature-rich, interactive report for sales and profits by products over select periods of time.

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