<Do>

The <Do> conditional allows you to implement Do/While style looping.

<Do> Attributes

<Do> supports the following attributes that change its behavior:

Attribute	Allowed Values	Default Value
expression	string expression to evaluate	none
maxLoops	integer > 0	1

expression

The expression attribute accepts a string of conditionals to evaluate. If the expression evaluates to true, then all verbs nested inside <Do> are executed. Otherwise, the nested verbs are ignored and the next VoXML instruction is executed.

maxLoops

The maxLoops attribute sets the maximum number of loops to execute before exiting the <Do> loop.

<Do> Examples

Simple Usage

Prompt the caller up to 3 times to enter DTMF 1 or 2.

<Response>
  <Do expression="${menu.digits}!~(1|2)" maxLoops="3">
    <Gather input="dtmf" output="menu">
      <Say>Hello. Press 1 to speak with support or 2 to speak with sales.</Say>
    </Gather>
  </Do>
</Response>

Advanced Usage

Prompt the caller up to 3 times for a six-digit account number, then read it back to them.

<Response>
  <Do expression="${account.digits}!~[0-9]{6}" maxLoops="3">
    <Gather input="dtmf" output="account" finishOnKey="#">
      <Say>Please enter your six-digit account number followed by the pound key.</Say>
    </Gather>
  </Do>
  <Say>You entered ${account.digits}.</Say>
</Response>