Free cookie consent management tool by TermsFeed Hierarchy Browser (Columns) Component (a!hierarchyBrowserFieldColumns)
Hierarchy Browser (Columns) Component

Function

a!hierarchyBrowserFieldColumns( label, labelPosition, instructions, helpTooltip, firstColumnValues, nodeConfigs, pathValue, pathSaveInto, nextColumnValues, selectionValue, selectionSaveInto, height, accessibilityText, showWhen )

Displays hierarchical data in the form of drillable columns with selectable cells.

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.
  • "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.

Instructions

instructions

Text

Supplemental text about this field.

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".

First Column Values

firstColumnValues

List of Variant

Values in the first column. For example, a!queryEntity(…).data or rule!CRM_getAllCustomers().

Node Configurations

nodeConfigs

HierarchyBrowserFieldColumnsNode

Describe how to display a value as a node using a!hierarchyBrowserFieldColumnsNode() and fv!nodeValue. This rule or expression is evaluated for each value where fv!nodeValue is any node value.

Navigation Path

pathValue

List of Variant

As the user clicks through the browser, clicked nodes become highlighted. These clicked nodes' values are in the pathValue. They should be stored in a variable, for example local!path. The clicked node's value is used to determine the next column, generated by nextColumnValues.

Save Navigation To

pathSaveInto

List of Save

Variable or list of variables to update when a user clicks on a drillable or selectable node, as determined by the node configurations. For example, local!path. Use a!save() to save a modified or alternative value to a variable.

Next Column Values

nextColumnValues

Any Type

Given a node value, describe how to get the next column’s values using the variable fv!nodeValue. For example, rule!CRM_getTicketsForCustomer(customer: fv!nodeValue, isActive: true). This rule or expression is evaluated for each value in pathValue where fv!nodeValue refers any value in pathValue.

Selection Value

selectionValue

Any Type

Value of the currently selected node. The selection will be indicated by a unique display if present in the navigation path.

Save Selection To

selectionSaveInto

List of Save

Variable or list of variables to update when a user clicks on a selectable node, as determined by the node configurations. Use a!save() to save a modified or alternative value to a variable.

Height

height

Text

Determines the height of the component.Valid values: "SHORT", "MEDIUM" (default), "TALL".

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

Columns and user and group browsers comparison

The columns browser component creates a Miller-columns-style browser that allows users to select a business object while browsing through a hierarchy of designer-specified business data.

The columns browser is a generalized version of the user and group browsers in the same way that the custom picker is a generalized version of the user and group pickers. The designer has control over what data is shown, how it is retrieved, and how it is displayed, making the component a flexible means of presenting hierarchical business data to users.

For more information on how the columns browser works, see this detailed explanation.

Selecting and displaying values

  • If firstColumnValues are not specified, only the label, tooltip, and instructions will display.
  • To make the selection required for submission or display validation messages based on the selection, pair the browser with a picker or other component.
  • The function variable fv!nodeValue is available when configuring the columns browser. It is only available in the nodeConfigs and nextColumnValues parameters.

Using the pathValue and pathSaveInto parameters

  • Because values can appear in multiple places in the browser at one time, a node only displays as selected if it is present in the pathValue array. If selectionValue appears twice in the pathValue array, the component highlights only the last node in the array whose value is the selected value.
  • When a selectable node is clicked, variables in pathSaveInto are updated before variables in Save Selection To. This means that if a variable is updated in both saves, it will be updated to the value assigned in the selectionSaveInto.
  • Clicking a selected node deselects the value by saving a null value as the selection. To be considered selected, the value must be at the end of the pathValue.
  • The first value in the pathValue must be included in the firstColumnValues. Each subsequent value in the pathValue must be included in the nextColumnValues generated by the previous value in the pathValue. For example, if pathValue is {1, 10}, then 1 must be present in firstColumnValues and 10 must be present in the nextColumnValues generated by 1.

Examples

Copy and paste an example into the INTERFACE DEFINITION in EXPRESSION MODE to see it displayed.

Columns browser

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a!localVariables(
  local!path,
  local!selection,
  local!numberOfNodesInFirstColumn: 10,
  local!firstColumnValues: a!foreach(
    enumerate(local!numberOfNodesInFirstColumn),
    a!localVariables(
      /* Give it a random number of children between 0 and 20 */
      local!numberOfChilren: tointeger(rand() * 20),
      /* Make only even numbers drillable */
      local!isDrillable: mod(fv!item, 2) = 0,
      /* Make only even numbers divisble by 3 selectable */
      local!isSelectable: mod(fv!item, 3) = 0,
      {
        id: fv!item,
        name: "Node " & fv!item,
        type: if(
          rand() > .5,
          "HAPPY",
          "SAD"
        ),
        numberOfChildren: local!numberOfChilren,
        isDrillable: local!isDrillable,
        isSelectable: local!isSelectable
      }
    )
  ),
  a!hierarchyBrowserFieldColumns(
    firstColumnValues: local!firstColumnValues,
    nodeConfigs: a!hierarchyBrowserFieldColumnsNode(
      id: fv!nodeValue.id,
      label: fv!nodeValue.name,
      image: a!documentImage(
        document: if(
          fv!nodeValue.type = "HAPPY",
          a!iconIndicator("FACE_HAPPY"),
          a!iconIndicator("FACE_SAD")
        )
      ),
      nextLevelCount: fv!nodeValue.numberOfChildren,
      isDrillable: fv!nodeValue.isDrillable,
      isSelectable: fv!nodeValue.isSelectable
    ),
    pathValue: local!path,
    pathSaveInto: local!path,
    selectionValue: local!selection,
    selectionSaveInto: local!selection,
    nextColumnValues: a!foreach(
      enumerate(fv!nodeValue.numberOfChildren),
      a!localVariables(
        /* Give it a random number of children between 0 and 20 */
        local!numberOfChilren: tointeger(rand() * 20),
        /* Make only even numbers drillable */
        local!isDrillable: mod(fv!item, 2) = 0,
        /* Make only even numbers divisble by 3 selectable */
        local!isSelectable: mod(fv!item, 3) = 0,
        {
          id: fv!item,
          name: "Node " & fv!item,
          /* Make the node randomly happy or sad */
          type: if(
            rand() > .5,
            "SAD",
            "HAPPY"
          ),
          numberOfChildren: local!numberOfChilren,
          isDrillable: local!isDrillable,
          isSelectable: local!isSelectable
        }
      )
    )
  )
)

Columns browser example breakdown and explanation

If you want more information on how the columns browser's inputs produce the rendered component, read through this section. This section provides a step-by-step breakdown of how the values provided to the component generate the component's data and guide its display. The interface in this section can be created by pasting the following expression into the INTERFACE DEFINITION in EXPRESSION MODE.

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a!localVariables(
  local!path: {4,2},
  local!selection: 2,
  a!hierarchyBrowserFieldColumns(
    firstColumnValues: enumerate(9),
    nodeConfigs: a!hierarchyBrowserFieldColumnsNode(
      id: fv!nodeValue,
      label: "Node" & fv!nodeValue,
      image: a!documentImage(document: a!iconIndicator("PREVIEW")),
      isDrillable: 1 - mod(fv!nodeValue, 2),
      isSelectable: mod(fv!nodeValue, 3),
      nextColumnCount: fv!nodeValue
    ),
    pathValue: local!path,
    nextColumnValues: enumerate(fv!nodeValue),
    selectionValue: local!selection,
    pathSaveInto: local!path,
    selectionSaveInto: local!selection
  )
)

To configure the columns browser details:

  1. The first step in building the browser is generating the values shown in the first column. You provide these values to the component through firstColumnValues. screenshot breaking down the nodes by one level
  2. Next, the component must know how to display these values as nodes. The component gets the display information from nodeConfigs. screenshot breaking down the nodes by two levels
    • As the purple text (number two) shows, the display information for the nodes in the first column comes from evaluating nodeConfigs for each value in firstColumnValues. Each evaluation of nodeConfigs needs to produce a Columns Browser Node. In this example, the first value in firstColumnValues is 0. Therefore, the first node in the first column comes from evaluating nodeConfigs with fv!nodeValue set to 0.
  3. The component shows an additional column for each value in pathValue. screenshot breaking down the nodes by three levels
    • The green arrow (number three) points to the two values in pathValue. The actual values are 4 and 2 and are displayed as "Node4" in column one and "Node2" in column two, respectively.
  4. The values in columns two and three are generated by nextColumnValues. screenshot breaking down the nodes by four levels
    • The orange text (number four) shows that the second and third columns' values are generated by evaluating nextColumnValues for each value in pathValue. In this example, the first value in pathValue is 4. The component uses this value to generate the second column's values by evaluating nextColumnValues with fv!nodeValue set to 4.
  5. Once again, the component determines how to display these values as nodes using nodeConfigs.</li> screenshot breaking down the nodes by five levels
    • The maroon text (number 5) shows that the component evaluates nodeConfigs for each value generated by nextColumnValues.
  6. Finally, the selected value is highlighted blue. screenshot breaking down the nodes by six levels
    • In this case, selectionValue is 2. Notice that 2 actually appears twice in browser, once in column one and once in column two. Only the value in the second column is highlighted because pathValue in the second column is also 2, whereas pathValue in the first column is 4.

Feature compatibility

The table below lists this component's compatibility with various features in Appian.
Feature Compatibility Note
Portals Compatible
Offline Mobile Incompatible
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 Hierarchy Browser (Columns) Component.

Hierarchy Browser (Columns) Component

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