Custom Picker Component (a!pickerFieldCustom)

Pickers

Custom Picker Component

Function

a!pickerFieldCustom( label, instructions, required, readOnly, disabled, maxSelections, suggestFunction, selectedLabels, selectedTooltips, value, validations, saveInto, validationGroup, requiredMessage, labelPosition, placeholder, helpTooltip, selectedLinks, accessibilityText, showWhen )

Displays an autocompleting input for the selection of one or more items from an arbitrary data set. For an example of how to configure the picker, see the Configure an Array Picker SAIL Recipe.

See also: DataSubset

Parameters

Name	Keyword	Types	Description
Label	`label`	Text	Text to display as the field label.
Instructions	`instructions`	Text	Supplemental text about this field.
Required	`required`	Boolean	Determines if a value is required to submit the form. Default: false.
Read-only	`readOnly`	Boolean	Determines if the field should display as not editable. Default: false.
Disabled	`disabled`	Boolean	Determines if the field should display as potentially editable but grayed out. Default: false.
Maximum Selections	`maxSelections`	Number (Integer)	Maximum number of allowed selections. Once this number is reached, further selections are blocked until a selection is removed.
Suggestion Function	`suggestFunction`	Any Type	A reference to a rule or function that populates the suggestion pane. The rule or function must take a single Text parameter and must return a DataSubset, created via a!dataSubset() or a plug-in function, where "data" contains the labels to display and "identifiers" contains the values to save.
Selected Labels	`selectedLabels`	List of Text String	Array of text display labels for the currently selected items.
Selection Tooltips	`selectedTooltips`	List of Text String	Array of text tooltips for the currently selected items.
Display Value	`value`	Any Type	Array of selected identifiers.
Validations	`validations`	List of Text String	Validation errors to display below the field when the value is not null.
Save Input To	`saveInto`	List of Save	One or more variables that are updated with the array of selected identifiers when the user adds or removes an item. 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.
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. `"COLLAPSED"` Hides the label. The label will still be read by screen readers; see accessibility considerations for more information. `"JUSTIFIED"` Aligns the label alongside the component starting at the edge of the page.
Placeholder	`placeholder`	Text	Text to display in the field when it is empty. Does not show if the field is read only.
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"`.
Selected Links	`selectedLinks`	List of Variant	Array of links to apply to the selected tokens. Create links with a!authorizationLink(), a!documentDownloadLink(), a!dynamicLink(), a!newsEntryLink(), a!processTaskLink(), a!recordLink(), a!reportLink(), a!safeLink(), a!startProcessLink(), a!submitLink(), or a!userRecordLink().
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.

Usage considerations

Using the suggestionFunction parameter

When a user types in the picker's text box, the text they type is passed to the suggestionFunction parameter. The returned data-subset must have a text array as data. Each item in that array is a selectable suggestion in the pane. If a suggestion is picked, the component's value is updated with the object at the same index of the data-subset's identifiers array (in addition to any existing selected identifiers).

Text lengths and placeholders

selectedLabels, selectedValues, selectedLinks, and selectedTooltips must all be the same length.
Whether placeholder text clears on focus or input varies by device and browser.

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.

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.

The following patterns include usage of the Custom Picker Component.

Configure an Array Picker (Pickers): Allow users to choose from a long text array using an auto-completing picker.
Configure an Array Picker that Ignores Duplicates (Pickers): Allow users to choose from a long text array using an autocompleting picker and prevent any choice from being picked multiple times.
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.