dropdownWithAdd

• Description: Dropdown with a "+" (add) button that appends the selected value to another target field (typically a textarea). Used for building up values incrementally - when user selects an option and clicks the add button, the selected value is concatenated/appended to a separate input field. The dropdown options can contain complex objects with multiple properties (e.g., formula and description), where selecting an option can populate preview/description fields before appending.
• Base Type: control
• Data Type: String (From list)
• Behavior:
  • User selects an option from the dropdown
  • Selecting an option populates read-only preview fields (Formula, Description)
  • Clicking the "+" button appends the formula to the target textarea field
  • Allows building complex values incrementally (e.g., combining multiple regex patterns)
• Example Values: Number, Email Address, IP Address, URL
• Common Use Cases: Building regular expressions from predefined patterns, Combining multiple formula components, Incremental value construction
• Required Properties:
  • controlOptions (Array): List of options, each with key (can be an object with additional properties like formula, description) and value (display label)
• Optional Properties:
  • value (String): Default selected value
  • styleClass (String): CSS class for styling (e.g., "one-line")
• Note: This control is typically used together with other controls - a target textarea where values are appended, and optional read-only preview fields.

JSON Example (Full Activity Context):

[
  {
    "key": "MatchFormula",
    "label": "Regular Expression",
    "baseType": "control",
    "controlType": "textarea",
    "styleClass": "xl-textarea",
    "value": "",
    "required": true
  },
  {
    "key": "regexSelector",
    "label": "Choose Regular Expression",
    "baseType": "control",
    "controlType": "dropdownWithAdd",
    "styleClass": "one-line",
    "controlOptions": [
      {
        "key": {
          "formula": "[0-9]+",
          "description": "Matches any number of at least 1 digit."
        },
        "value": "Number"
      },
      {
        "key": {
          "formula": "\\b([a-zA-Z0-9._%+-]+)@([a-zA-Z0-9.-]+\\.[a-zA-Z]{2,4})\\b",
          "description": "Matches a valid email address."
        },
        "value": "Email Address"
      },
      {
        "key": {
          "formula": "[\\w]+",
          "description": "Returns all alphanumeric words in a sentence."
        },
        "value": "All Words"
      }
    ]
  },
  {
    "key": "formulaDescription",
    "label": "Description",
    "baseType": "control",
    "controlType": "textarea",
    "readonly": true,
    "value": ""
  },
  {
    "key": "formulaDisplay",
    "label": "Formula",
    "baseType": "control",
    "controlType": "textarea",
    "readonly": true,
    "value": ""
  }
]