In website interactions forms, a textarea element displays a multi-line text input without the extra functionality of an editor.

start:
  await:
    form:
      title: Example
      elements:
        textarea/prompt_comment:
          label: Please share your experience:

Syntax

label:

The optional label to display above the form element.

required@bool:

If user input is required on this element use a value of yes. Otherwise, omit.

placeholder:

An optional tooltip displayed in the text box when there is no input.

default:

An optional default value.

max_length:

An optional maximum length for the text input (default 1024).

min_length:

An optional minimum length for the text input.

truncate:

If input longer than max_length: is truncated (default yes) or unmodified.

validation:

An optional custom validation script. Any output is considered to be an error.

You can use if...elseif to check multiple conditions.

textarea/prompt_comment:
  label: Comment:
  validation@raw:
    {% if prompt_comment is empty %}
    A comment is required.
    {% elseif prompt_comment|length < 100 %}
    A comment must be at least 100 characters. 
    {% endif %}