openDAQ
Open data acquisition platform
GenericStructPtr< InterfaceType > Class Template Reference

Structs are immutable objects that contain a set of key-value pairs. The key, as well as the types of each associated value for each struct are defined in advance within a Struct type that has the same name as the Struct. More...

Detailed Description

template<typename InterfaceType>
class GenericStructPtr< InterfaceType >

Structs are immutable objects that contain a set of key-value pairs. The key, as well as the types of each associated value for each struct are defined in advance within a Struct type that has the same name as the Struct.

The Struct types are stored within a Type manager. In any given instance of openDAQ, a single Type manager should exist that is part of its Context.

When creating a Struct, the Type manager is used to validate the given dictionary of keys and values against the Struct type stored within the manager. If no type with the given Struct name is currently stored, a default type is created using the Struct field names and values as its parameters. When creating a Struct, fields that are part of the Struct type can be omitted. If so, they will be replaced by either null or, if provided by the Struct type, the default value of the field.

In the case that a field name is present that is not part of the struct type, or if the value type of the field does not match, construction of the Struct will fail.

NOTE: Field values of fields with the Core type ctUndefined can hold any value, regardless of its type.

Structs are an openDAQ core type (ctStruct). Several objects in openDAQ such as an Unit, or DataDescriptor are Structs, allowing for access to their fields through Struct methods. Such objects are, by definition, immutable - their fields cannot be modified. In order to change the value of a Struct-type object, a new Struct must be created.

A Struct can only have fields of Core type: ctBool, ctInt, ctFloat, ctString, ctList, ctDict, ctRatio, ctComplexNumber, ctStruct, or ctUndefined. Additionally, all Container types (ctList, ctDict) should only have values of the aforementioned types.

Public Member Functions

StructTypePtr getStructType () const
 Gets the Struct's type. More...
 
ListPtr< IStringgetFieldNames () const
 Gets a list of all Struct field names. More...
 
ListPtr< IBaseObjectgetFieldValues () const
 Gets a list of all Struct field values. More...
 
BaseObjectPtr get (const StringPtr &name) const
 Gets the value of a field with the given name. More...
 
DictPtr< IString, IBaseObjectgetAsDictionary () const
 Gets the field names and values of the Struct as a Dictionary. More...
 
Bool hasField (const StringPtr &name) const
 Checks whether a field with the given name exists in the Struct. More...
 

Member Function Documentation

◆ get()

BaseObjectPtr get ( const StringPtr name) const
inline

Gets the value of a field with the given name.

Parameters
nameThe name of the queried field.
Returns
The value of the field.

◆ getAsDictionary()

DictPtr<IString, IBaseObject> getAsDictionary ( ) const
inline

Gets the field names and values of the Struct as a Dictionary.

Returns
The Dictionary object with field names as keys, and field values as its values.

◆ getFieldNames()

ListPtr<IString> getFieldNames ( ) const
inline

Gets a list of all Struct field names.

Returns
The list of field names.

The list of names will be of equal length to the list of values. Additionally, the name of a field at any given index corresponds to the value stored in the list of values.

◆ getFieldValues()

ListPtr<IBaseObject> getFieldValues ( ) const
inline

Gets a list of all Struct field values.

Returns
The list of field values.

The list of names will be of equal length to the list of values. Additionally, the name of a field at any given index corresponds to the value stored in the list of values.

◆ getStructType()

StructTypePtr getStructType ( ) const
inline

Gets the Struct's type.

Returns
The Struct type

◆ hasField()

Bool hasField ( const StringPtr name) const
inline

Checks whether a field with the given name exists in the Struct.

Parameters
nameThe name of the checked field.
Returns
True if the a field with name exists in the Struct; false otherwise.