Dropdown component choice share choice list

Hello edwardc8281 ,

Yes, can be done in Appian. Could you please elaborate where you would be saving the selected values? Is this going to be a huge set of dropdowns or just a couple of dropdowns with this behavior. 

a huge set of dropdowns, meayb 10 or more

a!localVariables(
  local!labels1: {
    "Option 1",
    "Option 2",
    "Option 3",
    "Option 4",
    "Option 5",
    "Option 6",
    "Option 7",
    "Option 8",
    "Option 9",
    "Option 10",
    "Option 11",
    "Option 12"
  },
  local!value1,
  local!labels2: remove(
    local!labels1,
    wherecontains(local!value1, local!labels1)
  ),
  local!value2,
  local!labels3: remove(
    local!labels2,
    wherecontains(local!value2, local!labels2)
  ),
  local!value3,
  {
    a!dropdownField(
      choiceLabels: local!labels1,
      choiceValues: local!labels1,
      label: "Dropdown",
      labelPosition: "ABOVE",
      placeholder: "--- Select a Value ---",
      value: local!value1,
      saveInto: { local!value1 },
      searchDisplay: "AUTO",
      validations: {}
    ),
    a!dropdownField(
      choiceLabels: local!labels2,
      choiceValues: local!labels2,
      label: "Dropdown",
      labelPosition: "ABOVE",
      placeholder: "--- Select a Value ---",
      value: local!value2,
      saveInto: { local!value2 },
      disabled: a!isNullOrEmpty(local!value1),
      searchDisplay: "AUTO",
      validations: {}
    ),
    a!dropdownField(
      choiceLabels: local!labels3,
      choiceValues: local!labels3,
      label: "Dropdown",
      labelPosition: "ABOVE",
      placeholder: "--- Select a Value ---",
      value: local!value3,
      saveInto: { local!value3 },
      disabled: a!isNullOrEmpty(local!value2),
      searchDisplay: "AUTO",
      validations: {}
    )
  }
)

You might want to redo the code a little bit. This is an example of how you can handle.

Thanks Konduru, I have tried this way, but if I have a huge dropdowns, like I have 10 dropdown component, I should creat 10 labels and values, right? What I want is use a more common or easy way to imply my require.

I have also tried this way, but I failed.

a!localVariables(
  local!choiceLabels: {
    "Option 1",
    "Option 2",
    "Option 3",
    "Option 4",
    "Option 5",
    "Option 6",
    "Option 7",
    "Option 8",
    "Option 9",
    "Option 10",
    "Option 11",
    "Option 12"
  },
  local!choiceValues: { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 },
  local!checkedValue: a!refreshVariable(
    value: { ri!q1Choice, ri!q2Choice },
    refreshAlways: true
  ),
  local!uncheckedValue: a!refreshVariable(
    value: symmetricdifference(local!choiceValues, local!checkedValue),
    refreshAlways: true
  ),
  {
    a!dropdownField(
      choiceLabels: local!uncheckedValue,
      choiceValues: local!uncheckedValue,
      label: "Dropdown",
      labelPosition: "ABOVE",
      placeholder: "--- Select a Value ---",
      value: ri!q1Choice,
      saveInto: ri!q1Choice,
      searchDisplay: "AUTO",
      validations: {}
    ),
    a!dropdownField(
      choiceLabels: local!uncheckedValue,
      choiceValues: local!uncheckedValue,
      label: "Dropdown",
      labelPosition: "ABOVE",
      placeholder: "--- Select a Value ---",
      value: ri!q2Choice,
      saveInto: ri!q2Choice,
      searchDisplay: "AUTO",
      validations: {}
    )
  }
)

Create an expression rule to perform the logic and reuse based on the input value.

Did you consider to just use a multi dropdown field? I mean, by this logic, you can select each item only once.

Thanks, but the multi dropdown field is not suit for our business. What I want is the choice in one dropdown will impact on the choices value of other dropdown component.

OK, but I assume that you will then use different choices for the other dropdowns. And this is different from the issue in this discussion.