How to SendMail only once when conditions are met???

Given the following, hypothetically of course:

//+------------------------------------------------------------------+
//| ALERT.mq4 |
//| Copyright 2006, MetaQuotes Software Corp. |
//| http://www.metaquotes.net |
//+------------------------------------------------------------------+
#property copyright "Copyright 2006, MetaQuotes Software Corp."
#property link "http://www.metaquotes.net"

#property indicator_chart_window


//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+

int init()
{
return(0);
}
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function |
//+------------------------------------------------------------------+
int deinit()
{
//----

//----
return(0);
}
//+------------------------------------------------------------------+
//| Custom indicator iteration function |
//+------------------------------------------------------------------+

int start()
{

double Near = iMA(NULL,0,15,0,MODE_EMA,PRICE_CLOSE,0);
double PriceNow = Bid;

if (PriceNow > Near)

{
SendMail("From FX Data","Price > 15EMA!!!");
}

else if (PriceNow < Near)

{
SendMail("From FX Data","Price < 15EMA!!!");
}

return(0);
}


This will send an alert email when the price is greater than the 15EMA. This isn't the actual code of course it's just an example. I'm guessing I need an array in here somewhere to count how many times that alert will be sent when the condition(s) is met. I'm still not up the array mql chapter...This leads to another question, if the email is to be sent only once, would the indicator have to be loaded on the chart again to be active again? What I'd really like is the email to be sent once and a message box come up prompting me to 'Click OK to reload indicator" without having to drag it back on the chart window again...

Use a script for doing this. The whole idea of script is running something once and exit.

Try something like this:

int start()
{
double Near = iMA(NULL,0,15,0,MODE_EMA,PRICE_CLOSE,0);
double PriceNow = Bid;
bool UpAlerted = false;
bool DnAlerted = false;

if (PriceNow > Near)
{
if (UpAlerted==false)
{
SendMail("From FX Data","Price > 15EMA!!!");
UpAlerted = true;
DnAlerted = false;
}
}
else if (PriceNow < Near)
{
if (DnAlerted==false)
{
SendMail("From FX Data","Price < 15EMA!!!");
UpAlerted = false;
DnAlerted = true;
}
}
return(0);
}

For this to work you need at least declare UpAlerted and DnAlerted as statics. But even then, you will loose sync when restarting MT4. Writing them as global would solve it, but stil there is no a clean way to reset the alert.

OK:

I made it a script but once again I can't find the error of my ways. What this is 'supposed to do' is the following...

When price is above the 89 smoothed moving average AND the 8ema > 21ema AND the difference between the 8ema and the 21ema > 0.0002 AND the current bid equals the 15ema an alert sounds and an email is sent.

Opposite for the short alert.

It compiles fine and I watched these conditions get met three times yesterday (for a bull alert) but the script didn't do anything.

Am I missing something???

//+------------------------------------------------------------------+
//| TCSCRIPTALERTv1.mq4 |
//| Copyright 2006, MetaQuotes Software Corp. |
//| http://www.metaquotes.net |
//+------------------------------------------------------------------+
#property copyright "Copyright 2006, MetaQuotes Software Corp."
#property link "http://www.metaquotes.net"


//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+

int init()
{
return(0);
}
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function |
//+------------------------------------------------------------------+
int deinit()
{
//----

//----
return(0);
}
//+------------------------------------------------------------------+
//| Custom indicator iteration function |
//+------------------------------------------------------------------+

int start()
{

double Near = iMA(NULL,0,15,0,MODE_EMA,PRICE_CLOSE,0);
double PriceNow = Bid;
double Trend = iMA(NULL,0,89,0,MODE_SMA,PRICE_CLOSE,0);
double fast = iMA(NULL,0,8,0,MODE_EMA,PRICE_CLOSE,0);
double slow = iMA(NULL,0,21,0,MODE_EMA,PRICE_CLOSE,0);
double bullspread = (fast - slow);
double bearspread = (slow - fast);

// Delete previous screen text
ObjectDelete("script is running");
ObjectDelete("comment_label");
ObjectDelete("reload");

// Script running text
ObjectCreate("script is running",OBJ_LABEL,0,0,0);
ObjectSet("script is running",OBJPROP_XDISTANCE,0);
ObjectSet("script is running",OBJPROP_YDISTANCE,15);
ObjectSetText("script is running","TC SCRIPT ALERT ON",15,"Arial",Yellow);

// Conditions for BULL TC alert
if ((PriceNow > Trend) && (fast > slow) && (PriceNow==Near) && (bullspread > 0.0002))

{

//Alerts
SendMail("From Palmer - Data","BULL TC ALERT ON THE EUR-USD!!!");
Alert(Symbol() , " BULL ","TC ALERT!");
PlaySound("sirenhilo.wav");
ObjectCreate("comment_label",OBJ_LABEL,0,0,0);
ObjectSet("comment_label",OBJPROP_XDISTANCE,0);
ObjectSet("comment_label",OBJPROP_YDISTANCE,35);
ObjectSetText("comment_label","BULL TC ALERT!",15,"Arial",Lime);

ObjectCreate("reload",OBJ_LABEL,0,0,0);
ObjectSet("reload",OBJPROP_XDISTANCE,0);
ObjectSet("reload",OBJPROP_YDISTANCE,55);
ObjectSetText("reload","RELOAD SCRIPT",15,"Arial",Blue);

}

// If BEAR TC alert

else if ((PriceNow < Trend) && (fast < slow) && (bearspread < 0.0002) && (PriceNow == Near))

{
SendMail("From Palmer - Data","BEAR TC ALERT ON THE EUR-USD!!!");
Alert(Symbol() , " BEAR ","TC ALERT!");
PlaySound("sirenhilo.wav");
ObjectCreate("comment_label",OBJ_LABEL,0,0,0);
ObjectSet("comment_label",OBJPROP_XDISTANCE,0);
ObjectSet("comment_label",OBJPROP_YDISTANCE,35);
ObjectSetText("comment_label","BEAR TC ALERT!",15,"Arial",Red);

ObjectCreate("reload",OBJ_LABEL,0,0,0);
ObjectSet("reload",OBJPROP_XDISTANCE,0);
ObjectSet("reload",OBJPROP_YDISTANCE,55);
ObjectSetText("reload","RELOAD SCRIPT",15,"Arial",Blue);

}
return(0);
}

The difference is that script runs only once. Therefore you need to create a loop yourself. It should be something like this:

int start(){
bool not_done=true;
while(not_done){
....
if(your condition here){
SendMail();
not_done = false;
}
Seleep(1000);
}
}

This will run the script until condition is met and exit it after sending the email. Hope this helps.

Those two won't work together unless you set a "sleep" time between each other (won't work in an indicator though, only scripts and EAs).

Alert();
Sleep(500); // waiting a half second
PlaySound();

Thanks guys...I'll make those changes and see how it works out....

aktur:

I PM'd you about this but I'm 're-asking' here so others may benefit as well.

I'm having a little trouble inserting your loop in the correct place within the code. Can you possibly re-paste my code here with your loop???

Thanks

Here it is (I haven't tested it)

Thanks aktur...I'll check this out this evening.

Hmmm, that 'should have' worked last night. If you plot an 8,15,21 EMA and an 89 SMA on a 4 hour chart of the USDCHF there should have been an alert that sounded and an email sent. My chart shows that the 0400 bar (GMT +2) on 05/17 should have fired this off. I'm wondering if it has to do with the bid = 15EMA. Should this be if the bid < 15EMA???

Here's the chart. The lower dashed white line is the 89ema...

Hmm, that bool loop didn't do it. It should have sent the alert on the USDCHF today...still trying to figure this one out...

I think that you have an error in your trigger logic. The bool loop is only intended to fire once per alarm. It has nothing to do with triggering the alarm itself. I think you should look for a professional help from somebody who can check your logic.