Using formula-based alerts

Introduction

AmiBroker allows you to define formula-based alerts. When alert is triggered a text can be displayed, user-defined sound played back, e-mail notification can be sent and any external application can be launched. This is all handled by single AlertIF function.

By default all alerts generate text that is displayed in the Alert Output window.

To show this window you have to select Window->Alert Output menu.

There is also Easy Alerts window that allows you to define simple alerts that do not require any coding (but do not offer full flexibility of AlertIf function).

Settings

Alert - related settings are present in the "Alerts" tab of Tools->Preferences window.

It allows to define e-mail account settings, test sound output and define which parts of AmiBroker can generate alerts via AlertIF function.

E-mail setting page now allows to choose among most popular authorization schemes like: AUTH LOGIN (most popular), POP3-before-SMPT (popular), CRAM-MD5, LOGIN PLAIN.

"Enable alerts from" checkboxes allow you to selectively enable/disable alerts generated by Automatic analysis, Commentary/Interpretation and custom indicators.

Alert output window now has an additional column that shows the source of alert - if this is Automatic Analysis, Commentary or one of your custom indicators. This makes it easier to find out which part of AmiBroker generates alerts.

New in AmiBroker 5.30 - support for SSL (secure connection) used by GMail for example.

In order to enable SSL support you need to follow these steps:

1. Download and run SSL add-on from http://www.amibroker.com/bin/SSLAddOn.exe
2. Configure (Tools->Preferences->Alerts) with SSL enabled as shown below

AlertIF function

AlertIF function is similar to WriteIF. But instead of just writing the text to the output window (commentary/interpretation) it allows to:

The syntax is as follows:

AlertIf( BOOLEAN_EXPRESSION, command, text, type = 0, flags = 1+2+4+8, lookback = 1 );

1. BOOLEAN_EXPRESSION is the expression that if evaluates to True (non zero value) triggers the alert. If it evaluates to False (zero value) no alert is triggered. Please note that only lookback most recent bars are considered.

2. The command string defines the action taken when alert is triggered. If it is empty the alert text is simply displayed in the Alert output window (Window->Alert Output). Other supported values of command string are:

SOUND the-path-to-the-WAV-file
EMAIL
EXEC the-path-to-the-file-or-URL <optional args>

SOUND command plays the WAV file once.

EMAIL command sends the e-mail to the account defined in the settings (Tools->Preferences->E-mail). The format of the e-mail is as follows:

Subject: Alert type_name (type) Ticker on Date/Time
Body: text

EXEC command launches external application or file or URL specified after EXEC command. <optional args> are attached after file name and text is attached at the end

3. Text defines the text that will be printed in the output window or sent via e-mail or added as argument to the application specified by EXEC command

4. Type defines type of the alert. Pre-defined types are 0 - default, 1 - buy, 2 - sell, 3 - short, 4- cover. YOu may specify higher values and they will get name "other". Type is important. SEE THE COMMENTS BELOW.

5. Flags control behaviour of AlertIF function. This field is a combination (sum) of the following values:
( 1 - display text in the output window, 2 - make a beep (via computer speaker), 4 - don't display repeated alerts having the same type, 8 - don't display repeated alerts having the same date/time) By default all these options are turned ON.

6. lookback parameter controls how many recent bars are checked

Examples:

Buy = Cross( MACD(), Signal() );
Sell = Cross( Signal(), MACD() );
Short = Sell;
Cover = Buy;

AlertIF( Buy, "EMAIL", "A sample alert on "+FullName(), 1 );

AlertIF( Sell, "SOUND C:\\Windows\\Media\\Ding.wav", "Audio alert", 2 );

AlertIF( Short, "EXEC Calc.exe", "Launching external application", 3 );

AlertIF( Cover, "", "Simple text alert", 4 );

Note EXEC command uses ShellExecute function and allows not only EXE files but URLs too.

Internal logic

Alertif function implements internal logic in the form of finite state machine that prevents repeated signals of the same type from occuring. State (i.e. the TYPE of last alert) is stored on PER-SYMBOL basis. So each symbol has its "last alert" attached. For per-symbol logic, eee the flowchart below:

 

 

Notes

1. Please once again note that by default AlertIf function does not generate repetitive signals when the same scan is run multiple times. During experimentation you may prefer to get repeated signals in subsequent scans. To do so you should change default flags to 1 + 2:

AlertIF( condition, "", "Text", 1, 1+2 );

2. If you want to generate the alert only on COMPLETED bar you may need to add this code:

barcomplete = BarIndex() < LastValue(BarIndex());

AlertIF( barcomplete AND condition, "", "Text", 1 );

3. There are simpler functions that do actions like sending email, playing a sound or executing external program without being involved in complex internal logic: