Gmail script run on new mail recieved - google-apps-script

Question

I am trying to write a script that will forward mail from my work gmail to a personal email. The script needs to run only from Mon - Fri, between 4pm and 7am. The spot where I am getting stuck is being able to run the script every 5 mins during that time and forwarded only new mail.
Is their a google script api to do an action on received mail.(onRecieve)? Or I am I looking at adding a custom label and some if statements to ensure I don't forward duplicates.
Heres the generics of what I have going right now.
function startCustomTrigger()
{
ScriptApp.newTrigger('nonWorkHours').timeBased().everyMinutes(5).create();
}
function nonWorkHours() {
var date = new Date();
var day = date.getDay();
var hrs = date.getHours();
if ((day >= 1) && (day <= 5) && (hrs >= 16) && (hrs <= 7)) {
// forward email here
var thread = GmailApp.getInboxThreads(0,1)[0]; // get first thread in inbox
var message = thread.getMessages()[0]; // get first message
message.forward("example#example.com");
}
}
Updated script: FYI, works decent but needs some updating and cleaning.
/**
Forward unread inbox messages to personal email at desired hours. M - F from 4pm to 7am and Sat all day.
Also mark the messages that are forwarded with custom label "Forwarded(Non_Hours)" and marked as read.
Grab timestamp of last message that was forwarded and save as global script property.
tjones © 2015
TimeMailed
**/
// Custom trigger to run script every 5 mins
function startCustomTrigger()
{
ScriptApp.newTrigger('timeBound').timeBased().everyMinutes(5).create()
}
// Global Variables ====================================================================================================
var scriptProperties = PropertiesService.getScriptProperties();
//Grab current time of run
var startTime = new Date().getTime(); //Log the start of script--> combine with below Logger line
Logger.log("START OF RUN: " + Utilities.formatDate(new Date(startTime),Session.getScriptTimeZone(),'d MMM yy hh:mm:ss' )); //Log time into readable format
// Grab gmail inbox
var thread = GmailApp.search('is:unread'); //Grab all unread messages
var gmailMessages = GmailApp.getMessagesForThreads(thread); //Grab all the messages of given threads, set above
//Setup script timestamp properties
var lastForwardTime = scriptProperties.getProperties(); //Var for the timestamp of last message from last time scirpt ran
var keys = scriptProperties.getProperty('lastForward'); //The key from the lastForward timestamp
Logger.log("LAST TIMESTAMP OF MESSAGE FORWARDED: " + keys) //Log the key to the logger
Logger.log("label: " + GmailApp.createLabel("Forwarded(Non_Hours)")); //Create label, if exists will just overwrite
//Variable to set label "Forwarded(Non_Hours)" to threads being forwarded
var label = GmailApp.getUserLabelByName("Forwarded(Non_Hours)");
//Set some time formats to check if between M-F and 4pm to 7am
var date = new Date();
var day = date.getDay();
Logger.log(day);
var hrs = date.getHours();
Logger.log(hrs);
//=========================================================================================================================
if (hrs >= 16 && hrs <= 24) {
var inBound = true;
} else if (hrs >= 1 && hrs <= 6) {
inBound = true;
} else {
inBound = false;
}
function timeBound() {
if ((day >= 1) && (day <= 5) && (inBound == true)) {
timeMailed();
}
else if ((day >=6) && (day <=7)) {
timeMailed();
}
else {
Logger.log("Time is out of bounds, Within work hours: Sleeping for 5 mins");
}
}
// Meat and potatoes of forwarding
function timeMailed() {
for(var i=0;i<thread.length;i++){ //for loop for all the threads from above
var messagesForThread = gmailMessages[i]; //var for messages in threads
label.addToThread(thread[i]) // Set label to thread
GmailApp.markThreadRead(thread[i]); //Mark messages as read before forwarding them
for(var j=0;j<messagesForThread.length;j++){ //for loop to go through messages found above
// Get timestamps of messages for duplicate check
var messageDateTime = messagesForThread[j].getDate();
Logger.log(messagesForThread[j].getDate());
var messageEpocTime = messageDateTime.getTime();
Logger.log(messageDateTime.getTime());
// Compare message timestamp to lastForward key and make sure its newer than last check
if (messageEpocTime > scriptProperties.getProperty('lastForward')) {
scriptProperties.setProperty('lastForward', messageEpocTime); //Get date of messages and set as script property "lastForward"
messagesForThread[j].forward("tjones#livefake.com"); //forward the messages from above to forward address
Logger.log("Message with subject " + messagesForThread[j].getSubject() + " was forwarded")
}
else {
Logger.log("Message with subject " + messagesForThread[j].getSubject() + " was already forwarded within last 5 min check")
}
Logger.log("FINAL TIMESTAMP AT: " + scriptProperties.getProperty('lastForward') ); //Leave in final run to log last timestamp
}
}
}

Answer 1

what you have is a good start. to not forward duplicates you could use labels but its overkill in this case.
instead remember (in script properties service) the timestamp of the last email forwarded. then use search to only find emails "after" that time.
if you save the property after sending the email, you will never miss an email but may rarely send a duplicate if the sendmail call crashes right after sending.
If you instead save the property right before the mail you guarantee no duplicates but may miss some if it crashes right before sending the email.
look at docs and other s.o. questions for how to do a search "after:date". i have done this for dates but not datetime. if only date is supported you might need to skip some results or find a more efficient way to search.
using a label is good in the general case where there is no pattern to the sequence of emails. in your case new inbox mails are always consecutive.