ChatMessagePromptTemplate.messagePlaceholder constructor

ChatMessagePromptTemplate.messagePlaceholder(
  1. String variableName
)

Creates a MessagePlaceholder, a prompt template that assumes the variable is a ChatMessage.

This is useful when you want to use a single ChatMessage in the prompt. For example, when you decide the type of message at runtime (e.g. HumanChatMessage or FunctionChatMessage).

This is a convenience factory equivalent to MessagePlaceholder constructor.

If you need to add multiple messages, use ChatMessagePromptTemplate.messagesPlaceholder.

Example:

final promptTemplate = ChatPromptTemplate.fromPromptMessages([
  ChatMessagePromptTemplate.system('You are a helpful AI assistant'),
  ChatMessagePromptTemplate.messagesPlaceholder('history'),
  ChatMessagePromptTemplate.messagePlaceholder('input'),
]);
  • variableName the name of the placeholder variable.

Implementation

factory ChatMessagePromptTemplate.messagePlaceholder(
  final String variableName,
) {
  return MessagePlaceholder(variableName: variableName);
}