回應使用者的訴求

• Handle global action
  全域呼叫

// The dialog stack is cleared and this dialog is invoked when the user enters 'help'.
bot.dialog('help', function (session, args, next) {
    session.endDialog("This is a bot that can help you make a dinner reservation. <br/>Please say 'next' to continue");
})
.triggerAction({
    matches: /^help$/i,
});
bot.dialog('help', function (session, args, next) {
    session.endDialog("This is a bot that can help you make a dinner reservation. <br/>Please say 'next' to continue");
})
.triggerAction({
    matches: /^help$/i,
    onSelectAction: (session, args, next) => {
        // Add the help dialog to the dialog stack 
        // (override the default behavior of replacing the stack)
        session.beginDialog(args.action, args);
    }
});

這兩個範例都可以全域呼叫，
差別在於 onSelectAction 不會終止原本的dialog流程，結束之後，還是會回到原本的dialog.

• Handle contextual action
  接續上下文

// Dialog to ask for number of people in the party
bot.dialog('askForPartySize', [
    function (session) {
        builder.Prompts.text(session, "How many people are in your party?");
    },
    function (session, results) {
       session.endDialogWithResult(results);
    }
])
.beginDialogAction('partySizeHelpAction', 'partySizeHelp', { matches: /^help$/i });

// Context Help dialog for party size
bot.dialog('partySizeHelp', function(session, args, next) {
    var msg = "Party size help: Our restaurant can support party sizes up to 150 members.";
    session.endDialog(msg);
})

• Change the topic of conversation

改變dialog主題
也因為前述，triggerAction不加onSelectAction，可以清空目前的dialog對話邏緝，故可以改變主題

• End conversation

bot.dialog('orderDinner', [
    //...waterfall steps...
    // Last step
    function(session, results){
        if(results.response){
            session.dialogData.room = results.response;
            var msg = `Thank you. Your order will be delivered to room #${session.dialogData.room}`;
            session.endConversation(msg);
        }
    }
]);
bot.dialog('dinnerOrder', [
    //...waterfall steps...
])
.endConversationAction(
    "endOrderDinner", "Ok. Goodbye.",
    {
        matches: /^cancel$|^goodbye$/i,
        confirmPrompt: "This will cancel your order. Are you sure?"
    }
);

呼叫 endConversation　或是　endConversationAction 都可以結束這次的對話。