10 KiB
10 KiB
ObjectGetDouble
The function returns the value of the corresponding object property. The object property must be of the double type. There are 2 variants of the function.
- Immediately returns the property value.
double ObjectGetDouble(
long chart_id, // chart identifier
string name, // object name
ENUM_OBJECT_PROPERTY_DOUBLE prop_id, // property identifier
int prop_modifier=0 // property modifier, if required
);
- Returns true or false, depending on the success of the function. If successful, the property value is placed to a receiving variable passed by reference by the last parameter.
bool ObjectGetDouble(
long chart_id, // chart identifier
string name, // object name
ENUM_OBJECT_PROPERTY_DOUBLE prop_id, // property identifier
int prop_modifier, // property modifier
double& double_var // here we accept the property value
);
Parameters
chart_id
[in] Chart identifier. 0 means the current chart.
name
[in] Name of the object.
prop_id
[in] ID of the object property. The value can be one of the values of the ENUM_OBJECT_PROPERTY_DOUBLE enumeration.
prop_modifier
[in] Modifier of the specified property. For the first variant, the default modifier value is equal to 0. Most properties do not require a modifier. It denotes the number of the level in Fibonacci tools and in the graphical object Andrew's pitchfork. The numeration of levels starts from zero.
double_var
[out] Variable of the double type that received the value of the requested property.
Return Value
Value of the double type for the first calling variant.
For the second variant the function returns true, if this property is maintained and the value has been placed into the double_var variable, otherwise returns false. To read more about the error call GetLastError().
Note
The function uses a synchronous call, which means that the function waits for the execution of all commands that have been enqueued for this chart prior to its call, that is why this function can be time consuming. This feature should be taken into account when working with a large number of objects on a chart.
Example:
#property copyright "Copyright 2025, MetaQuotes Ltd."
#property link "https://www.mql5.com"
#property version "1.00"
#define OBJ_NAME "TestObjectGetDouble" // Object name
#define WND 0 // Chart subwindow
#define EXT " (%$)" // Format string for displaying price values at levels
//+------------------------------------------------------------------+
//| Script program start function |
//+------------------------------------------------------------------+
void OnStart()
{
//--- current chart ID, the chart symbol, and symbol Digits
long chart_id= ChartID();
string symbol = ChartSymbol(chart_id);
int digits = (int)SymbolInfoInteger(symbol, SYMBOL_DIGITS);
//--- construct the Fibonacci Levels graphical object at the maximum and minimum prices of the visible chart
if(!CreateFibo(chart_id))
return;
//--- number of object levels
int total=(int)ObjectGetInteger(chart_id, OBJ_NAME, OBJPROP_LEVELS);
double value =0;
double price0=0;
double price1=0;
//--- anchor point prices
price0=ObjectGetDouble(chart_id, OBJ_NAME, OBJPROP_PRICE, 0);
price1=ObjectGetDouble(chart_id, OBJ_NAME, OBJPROP_PRICE, 1);
//--- in a loop by the number of object levels
for(int i=0; i<total; i++)
{
//--- get the value set for the current level
ResetLastError();
if(!ObjectGetDouble(chart_id, OBJ_NAME, OBJPROP_LEVELVALUE, i, value))
{
Print("ObjectGetDouble() failed. Error ", GetLastError());
return;
}
//--- get the maximum and minimum prices of the object binding and the distance between them in the price value
double max=fmax(price0, price1);
double min=fmin(price0, price1);
double range=max-min;
//--- calculate the price value for the current level of the object
double level_price=min+range*value;
//--- set the color for the level so that it is visible on both dark and light backgrounds of the chart
ObjectSetInteger(chart_id, OBJ_NAME, OBJPROP_LEVELCOLOR, i, clrRed);
//--- set a format string for the level so that its price value is displayed along with the level value
string level_text=ObjectGetString(chart_id, OBJ_NAME, OBJPROP_LEVELTEXT, i);
if(StringFind(level_text, EXT)<0)
{
level_text+=EXT;
ObjectSetString(chart_id, OBJ_NAME, OBJPROP_LEVELTEXT, i, level_text);
}
//--- output the level number and its data - the level value and its price - in the journal
PrintFormat("Fibo level [%d] value: %.3f, price: %.*f", i, value, digits, level_price);
}
/*
result:
Fibo level [0] value: 0.000, price: 0.61989
Fibo level [1] value: 0.236, price: 0.62533
Fibo level [2] value: 0.382, price: 0.62869
Fibo level [3] value: 0.500, price: 0.63140
Fibo level [4] value: 0.618, price: 0.63412
Fibo level [5] value: 1.000, price: 0.64292
Fibo level [6] value: 1.618, price: 0.65715
Fibo level [7] value: 2.618, price: 0.68018
Fibo level [8] value: 4.236, price: 0.71745
*/
}
//+------------------------------------------------------------------+
//| Create the Fibo levels graphical object on the specified chart |
//+------------------------------------------------------------------+
bool CreateFibo(const long chart_id)
{
//--- draw Fibo levels from the highest to the lowest visible price values on the chart and get them
double price_high=0, price_low=0;
datetime time_high =0, time_low =0;
if(!GetChartExtremums(chart_id, price_high, price_low, time_high, time_low))
return(false);
//--- construct the Fibo Levels object on the found price/time coordinates
if(!ObjectCreate(chart_id, OBJ_NAME, OBJ_FIBO, WND, time_high, price_high, time_low, price_low))
{
PrintFormat("%s: ObjectCreate() failed. Error %d",__FUNCTION__, GetLastError());
return(false);
}
//--- all is well - update the chart and return 'true'
ChartRedraw();
return(true);
}
//+------------------------------------------------------------------+
//| Return the maximum and minimum prices on the chart and their time|
//+------------------------------------------------------------------+
bool GetChartExtremums(const long chart_id, double &price_high, double &price_low, datetime &time_high, datetime &time_low)
{
//--- reset the variables
price_high=price_low=0;
time_high =time_low =0;
//--- chart symbol
string symbol = ChartSymbol(chart_id);
//--- calculate the start of the range of copied timeseries based on the number of the first visible bar and the number of bars on the chart
int first = (int)ChartGetInteger(chart_id, CHART_FIRST_VISIBLE_BAR);
int count = (int)ChartGetInteger(chart_id, CHART_VISIBLE_BARS);
int start = first+1-count;
//--- arrays where timeseries are to be copied
double array_high[];
double array_low[];
datetime array_time[];
int index;
//--- copy three timeseries into arrays in the amount of 'count' and starting from 'start'
ResetLastError();
if(CopySeries(symbol, PERIOD_CURRENT, start, count, COPY_RATES_TIME|COPY_RATES_HIGH|COPY_RATES_LOW, array_time, array_high, array_low)!=count)
{
PrintFormat("%s: CopySeries() failed. Error %d",__FUNCTION__, GetLastError());
return(false);
}
//--- look for the maximum price index in the array_high array
index=ArrayMaximum(array_high);
if(index<0)
{
PrintFormat("%s: ArrayMaximum() failed. Error %d",__FUNCTION__, GetLastError());
return(false);
}
//--- remember the highest price on the visible chart and the time value of the bar this price is located on
price_high=array_high[index];
time_high=array_time[index];
//--- look for the minimum price index in the array_low array
index=ArrayMinimum(array_low);
if(index<0)
{
PrintFormat("%s: ArrayMinimum() failed. Error %d",__FUNCTION__, GetLastError());
return(false);
}
//--- remember the lowest price on the visible chart and the time value of the bar this price is located on
price_low=array_low[index];
time_low=array_time[index];
//--- all is fine
return(true);
}