Other Functions

You can use message notifications in your strategies. For instance, you may want to create a strategy that will instead of actively trading work as an advisor, notifying you about the right time to perform transactions. To do this, use the function ShowMessage(const s: String).

Example:

You need to get a message ‘Time to buy EURUSD’ every time when the difference between the open and the close price of the last finished candle is bigger than 20 points. You need the following lines:

procedure OnNewCandle;

begin

if (History.Last(1).Open – History.Last(1).Close > 20*History.Instrument.PointSize) then

ShowMessage('Time to Buy EURUSD’);

end;

ribbonactfx64

You can use sound notifications in your strategies. For instance, you can write a strategy that will play an audio file every time some event takes place. To do this, use the function PlaySound(const FileName: String).

Example:

You want to hear a notification every time when the rate becomes higher than 1.5000. You need the following lines:

procedure OnNewRate;

begin

if (History.Last(1).Rate < 1.5000) and (History.Last.Rate > 1.5000) then

PlaySound('E:\MySounds\HighRate.wav');

end;

As a result, the audio file HighRate.wav from the directory E:\MySounds will be played.

Note:

1) The Silent Mode in the WinClient settings should be disabled. Otherwise you will not hear any sounds.

2) The directory and file names should contain only Latin letters.

3) The file should be in the .wav format.

Function	Description
function Sqr(const X: Double): Double	Square
function Max(const A, B: Double): Double	The greater of the two numbers
function Min(const A, B: Double): Double	The lesser of the two numbers
function Round(e: Extended): Integer	Rounds to the nearest integer
function Trunc(e: Extended): Integer	Truncates the fractional part
function Int(e: Extended): Integer	Returns the integer part of the number
function Frac(X: Extended): Extended	Returns the fractional part
function Sqrt(e: Extended): Extended	Square root
function Abs(e: Extended): Extended	Absolute value
function Sin(e: Extended): Extended	Sine
function Cos(e: Extended): Extended	Cosine
function ArcTan(X: Extended): Extended	Arctangent
function Tan(X: Extended): Extended	Tangent
function Exp(X: Extended): Extended	Exponential
function Ln(X: Extended): Extended	Natural logarithm
function Pi: Extended	Pi

function EncodeDate(Year, Month, Day: Word): TDateTime	Converts year, month and day into a date
procedure DecodeDate(Date: TDateTime; var Year, Month, Day: Word)	Converts a date into year, month and day
function EncodeTime(Hour, Min, Sec, MSec: Word): TDateTime	Converts hours, minutes and seconds into time
procedure DecodeTime(Time: TDateTime; var Hour, Min, Sec, MSec: Word)	Converts time into hours, minutes and seconds
function Date: TDateTime	Current date
function Time: TDateTime	Current time
function Now: TDateTime	Current date and time
function DayOfWeek(aDate: DateTime): Integer	Day of the week
function IsLeapYear(Year: Word): Boolean	Check if leap year
function DaysInMonth(nYear, nMonth: Integer): Integer	Number of days in a month

function IntToStr(i: Integer): String	Converts an integer into a string
function FloatToStr(e: Extended): String	Converts a fractional number into a string
function DateToStr(e: Extended): String	Converts a date into a string
function TimeToStr(e: Extended): String	Converts time into a string
function DateTimeToStr(e: Extended): String	Converts date and time into a string
function StrToInt(s: String): Integer	Converts a string into an integer
function StrToFloat(s: String): Extended	Converts a string into a fractional number
function StrToDate(s: String): Extended	Converts a string into a date
function StrToTime(s: String): Extended	Converts a string into time
function StrToDateTime(s: String): Extended	Converts a string into date and time
function StrToColor(const HexRGB: String): TColor	Converts a string into color

function Length(s: String): Integer	Length of the string
function Copy(s: String; from, count: Integer): String	Returns a substring of the given length starting from the specified position
function Pos(substr, s: String): Integer	Returns the position of a substring within given string
procedure Delete(var s: String; from, count: Integer)	Removes a substring of the given length starting from the specified position
procedure Insert(s: String; var s2: String; pos: Integer)	Appends the second string to the first
function Uppercase(s: String): String	Converts the string into uppercase
function Lowercase(s: String): String	Converts the string into lowercase
function Trim(s: String): String	Removes blank spaces from the string
function NameCase(s: String): String	Converts the first letter into uppercase
function CompareText(s, s1: String): Integer	Compares two strings
function Chr(i: Integer): Char	Returns the character with specified position
function Ord(ch: Char): Integer	Returns the position of the specified character
procedure SetLength(var S: String; L: Integer)	Sets the length of a string

procedure Inc(var i: Integer; incr: Integer = 1)	Increment
procedure Dec(var i: Integer; decr: Integer = 1)	Decrement
procedure RaiseException(Param: String)	Generates error message
procedure Randomize	Initializes the random numbers generator
function Random: Extended	Generates a random number in the range between 0 and 1
function ValidInt(cInt: String): Boolean	Validates an integer
function ValidFloat(cFlt: String): Boolean	Validates a fractional number
function ValidDate(cDate: String): Boolean	Validates a date

TStringList class objects are used to save and load data to/from a .txt file.

In order to create such an object, use the method TStringList.Create.

Example:

procedure OnStart;

var

Settings: TStringList;

begin

Settings := TStringList.Create;

end;

This object has 5 properties:

a) Count: Integer – the number of strings in the list

b) Names[ ]: String – the name at a given index in the list
c) Values[ ]: String – the value for a given name when using name/value pair strings
d) Strings[ ]: String - the string at a given index in the list
e) Text: String – the whole list

There is a dual approach to store individual strings in a file. Each string can be stored as simple text (string), or if it contains the equals sign ('='), it can be treated as a name/value pair. The text on the left of the equals sign is regarded as a name, and the text on the right is regarded as a value.

This concept provides an alternative way to refer to a particular value. The values property returns the value for a given name, therefore it is not necessary to know the index of the string.

You can create a name/value string by simply assigning some value to some name.

Example:

MyParameters.Values['Amount'] := '5';

If the name 'Amount' is already present in the list, the corresponding value will be changed to 5. If there is no such name, a new string will be appended to the end of the list.

Example:

Let us create a name/value pair when a position is opened. We will store the position ticket # with the name 'Trade'. We will also output this information into the log.

var

MyParameters: TStringList;

procedure OnStart;

begin

MyParameters := TStringList.Create;

end;

procedure OnTradeChange;

begin

if Action = dmtInsert then

begin

MyParameters.Values ['Trade'] := Trade.Id;

MyParameters.SaveToFile ('c:\list.txt');

log ('Trade id: ' + MyParameters.Values['Trade'] );

end;

You can use the following methods when working with this object:

Methods	Description
TStringList.Create	Creates a TStringList object
TStringList.Add(const S: string): Integer	Adds a string to the list
TStringList.Clear	Clears the list
TStringList.Delete(Index: Integer)	Deletes the string with the given index from the list
TStringList.IndexOf(const S: string): Integer	Returns the index of the given string.
TStringList.IndexOfName(const Name: string): Integer	Returns the index of the string with a given name.
TStringList.Insert(Index: Integer; const S: string)	Inserts the given string into the given position.
TStringList.LoadFromFile(const FileName: string)	Loads the values from a file into the String list.
TStringList.SaveToFile(const FileName: string)	Saves the String list into the file.
TStringList.Free	Removes a TStringList object from memory

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