Subscription Class

Subscription Class

A Subscription object holds information about a subscription for topic updates and comprises of two primary fields: a 'CorrelationId' associated with the subscription, and a string, called a subscription string, describing the data to be delivered as a part of the subscription.

Inheritance Hierarchy

SystemObject
Bloomberglp.BlpapiSubscription

Namespace: Bloomberglp.Blpapi
Assembly: Bloomberglp.Blpapi (in Bloomberglp.Blpapi.dll) Version: 3.19.2.1

Syntax

C++

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public class Subscription

Public Class Subscription

public ref class Subscription

type Subscription =  class end

The Subscription type exposes the following members.

Constructors

	Name	Description
	Subscription(String)	Create a Subscription object with the specified subscription string. Subscription(String, CorrelationID)
	Subscription(String, CorrelationID)	Initializes a new instance of the Subscription class
	Subscription(String, Boolean)	Creates a Subscription object with the specified subscriptionString, and the specified isResolved flag and an internally generated CorrelationID . If the isResolved is set to true, the subscriptionString is assumed to be a fully-resolved topic string. Note that even if isResolved flag is true, it is still at the discretion of each function operating on Subscription to perform resolution (again) on this topic or not.
	Subscription(String, IListString)	Creates a Subscription object with the specified security and fields. Subscription(String, IListString, IListString, CorrelationID)
	Subscription(String, String)	Creates a Subscription object with the specified security and fields with no options and an internally generated CorrelationID.
	Subscription(String, CorrelationID, Boolean)	Creates a Subscription object with the specified subscriptionString, the specified correlationID for correlation, and the specified isResolved flag. If the isResolved is set to true, the subscriptionString is assumed to be a fully-resolved topic string. Note that even if isResolved flag is true, it is still at the discretion of each function operating on Subscription to perform resolution (again) on this topic or not.
	Subscription(String, IListString, CorrelationID)	Creates a Subscription object with the specified security, fields and correlationId.
	Subscription(String, IListString, IListString)	Creates a Subscription object with the specified security, fields and options.
	Subscription(String, String, CorrelationID)	Creates a Subscription object with the specified security and fields with no options and the specified correlationId.
	Subscription(String, String, String)	Creates a Subscription object with the specified security, fields and options and an internally generated CorrelationID.
	Subscription(String, IListString, IListString, CorrelationID)	Initializes a new instance of the Subscription class
	Subscription(String, String, String, CorrelationID)	Creates a Subscription object with the specified security, fields, options and correlationId.

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Properties

	Name	Description
	CorrelationID
	IsResolved	Returns true if the object was created with the isResolved flag set for the topic string, otherwise returns false.
	SubscriptionStatus	Obsolete. Return the subscription status.
	SubscriptionString	Subscription string

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Methods

	Name	Description
	ToString	Return the string representation of this object. (Overrides ObjectToString.)

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Remarks

The simplest form of a subscription string is a fully qualified subscription string, which has the following structure:

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"//blp/mktdata/ticker/IBM US Equity?fields=BID,ASK&interval=2"
 \-----------/\------/\-----------/\------------------------/
       |          |         |                  |
    Service     Prefix   Instrument          Suffix

Such a fully-qualified string is composed of:

Service Identifier: a string matching the expression ^//[-_.a-zA-Z0-9]+/[-_.a-zA-Z0-9]+$, e.g. //blp/mktdata.
Prefix: a string matching the expression /([-_.a-zA-Z0-9]+/)?, often used as a symbology identifier.
Instrument: a non-empty string that does not contain the character? (i.e. a string matching [^?]+) e.g. "IBM US Equity", or "SPX Index". The service, prefix, and instrument together uniquely identify a source for subscription data.
Suffix: a suffix contains a question mark followed by a list of options which can affect the content delivery. The format of these options is service specific, but they generally follow URI query string conventions: a sequence of "key=value" pairs separated by "&" characters.Further, many common services follow the convention that the value given for the 'fields' key is formatted as a comma-separated list of field names.BLPAPI provides several convenience functions to assist in formatting subscription strings for services that make use of these conventions.

Note that subscription strings need not be fully qualified: BLPAPI allows the service and prefix to be omitted from subscription strings, and automatically qualifies these strings using information stored in a 'Session' object. It is used to create a list of Subscription objects that can be used for Subscribe(), Resubscribe(), and Unsubscribe() requests.

Reference

Bloomberglp.Blpapi Namespace