Promotic

ItemEx - method of the PmaData object

Description:
The method returns object of the PmVar type that represents one variable defined on the "Data" tab.
Syntax:
Object ItemEx(Variant id, Long nAttr)
Parameters:
id(Variant) Specifies the variable. The value je:
- Name (String, case sensitive text, for example "d1") or
- Index (Long, zero-based index)
nAttr(Long) It allows to change the behavior of the method.
0 (default) - default behavior (as the Item method).
1 - When referencing the non-existing object, the global error of the INFO system will not be generated.
Note:
The PmVar object contains information about the variable (value, name, index, etc.).
If the variable does not exist, then error value (null for JavaScript or Nothing pro VBScript) is returned. Nothing value can be tested by VBScript Is operator.

Identifier #vars: The reference to PmVar object can also be done directly by extending the path of the Pm method by means of the #vars identifier. This identifier can be used e.g. in the Pm method, or for the PP data binding in the application and in panels. For example the method Pm("/data/#vars/Temperature) returns the "Temperature" variable (PmVar object) in the data object (PmaData object).
 
Identifier #ext: References to Data extensions objects in the PmVar variable can also be done directly by extending the path of the Pm method using the #ext identifier. This can be used in the Pm method or in PP binding in the application and in panels. For example the method pMe.Pm("/data/#vars/Temperature/#ext/al") returns the data extension with al identifier (ExtAlarmAnalog) in the "Temperature" variable (PmVar) in the data object (PmaData object).
See also:
- PmaData.Item (method)
Example1:
JavaScriptVBScriptSelect and copy to clipboard

var oData = pMe.Pm("/Data");
var oItemEx = oData.ItemEx(0);   // Access to the object that represents the variable

var value = oItemEx.Value;   // Reading the value
oItemEx.Value = 8;   // Writing the value
Example2:
Test whether the variable named "Temperature3" exists:
JavaScriptVBScriptSelect and copy to clipboard

var oData = pMe.Pm("/Data");
var oItem = oData.ItemEx("Temperature3", 1);
if (!oItem)
{
// ...
}
PROMOTIC 9.0.21 SCADA system documentation - MICROSYS, spol. s r.o.

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