C# Class Examples.ControlClientUpdatingRecordTopics

An example of using a control client to create and update a record topic in exclusive mode. This uses the topic control feature to create a topic and the topic update control feature to send updates to it. Both 'full' and 'patch' updating techniques are demonstrated. Full updates involve sending the whole topic state to the server; this will be compared with the current state and a delta of any differences published to subscribed clients. With patch updates it is only necessary to send the values of the fields that have changed to the server where they will be applied to the current topic state and published to subscribers. The latter mechanism is not so well suited to this example where there are only 2 fields, but for topics with many fields this could represent considerable savings in the amount of data sent to the server. To send updates to a topic, the client session requires the 'update_topic' permission for that branch of the topic tree. The example also demonstrates a simple usage of a structured record builder for generating content as such a builder validates the input against the metadata.

ファイルを表示 Open project: pushtechnology/diffusion-examples

Public Methods

Method	Description
AddRate ( string currency, string targetCurrency, string bid, string ask, ITopicControlAddContextCallback callback ) : void	Adds a new conversion rate in terms of base currency and target currency. The bid and ask rates are entered as strings which may be a decimal value; this will be parsed and validated, rounding to 5 decimal places. If a zero-length string ("") is supplied, the rate will be set to 'empty' and clients will receive a zero-length string in the initial load.
ChangeBidRate ( string currency, string targetCurrency, string bid, ITopicUpdaterUpdateContextCallback callback ) : void	Updates just the 'bid' value for a specified rate. This method demonstrates the alternative 'delta' mechanism of updating. In this example it does not make much sense, but for records with many fields where you know only one is changing, this negates the need to send the whole topic state in each update.
ChangeRate ( string currency, string targetCurrency, string bid, string ask, ITopicUpdaterUpdateContextCallback callback ) : void	Update a rate. The rate in question must have been added first using AddRate otherwise this will fail. The bid and ask rates are entered as strings which may be a decimal value; this will be parsed and validated, rounding to 5 decimal places. A zero-length string may be supplied to indicate 'no rate available'. The server will compare the supplied values with the current values, and if different will notify clients of a delta of change. Only changed fields are notified to clients - unchanged fields are passed as a zero-length string. If a field has changed to zero length, the client will receive the special empty field value in the delta.
Close ( ) : void	Close the session.
ControlClientUpdatingRecordTopics ( string serverUrl ) : System	Constructor.
RemoveCurrency ( string currency, ITopicControlRemoveContextCallback callback ) : void	Removes a currency (removes its topics and all subordinate rate topics).
RemoveRate ( string currency, string targetCurrency, ITopicControlRemoveContextCallback callback ) : void	Remove a rate (removes its topic).

Private Methods

Method	Description
CreateRateContent ( string bid, string ask ) : IContent	Create rate contents for a full update.
RateTopicName ( string currency, string targetCurrency ) : string	Generates a hierarchical topic name for a rate topic. e.g. for currency=GBP and targetCurrency=USD, this would return "FX/GBP/USD".

Method Details

AddRate() public method

Adds a new conversion rate in terms of base currency and target currency. The bid and ask rates are entered as strings which may be a decimal value; this will be parsed and validated, rounding to 5 decimal places. If a zero-length string ("") is supplied, the rate will be set to 'empty' and clients will receive a zero-length string in the initial load.

public AddRate ( string currency, string targetCurrency, string bid, string ask, ITopicControlAddContextCallback callback ) : void
currency	string	The base currency (e.g. GBP).
targetCurrency	string	The target current (e.g. USD).
bid	string	The 'bid' rate.
ask	string	The 'ask' rate.
callback	ITopicControlAddContextCallback	A callback which will be called to report the outcome. The context in the callback /// wil be currency/target currency (e.g. "GBP/USD").
return	void

ChangeBidRate() public method

Updates just the 'bid' value for a specified rate. This method demonstrates the alternative 'delta' mechanism of updating. In this example it does not make much sense, but for records with many fields where you know only one is changing, this negates the need to send the whole topic state in each update.

public ChangeBidRate ( string currency, string targetCurrency, string bid, ITopicUpdaterUpdateContextCallback callback ) : void
currency	string	The base currency.
targetCurrency	string	The target currency.
bid	string	The new bid rate which can be an empty string to set to 'not available'.
callback	ITopicUpdaterUpdateContextCallback	A callback which will be called to report the outcome. The context in the callback /// will be currency/targetCurrency (e.g. "GBP/USD".
return	void

ChangeRate() public method

Update a rate. The rate in question must have been added first using AddRate otherwise this will fail. The bid and ask rates are entered as strings which may be a decimal value; this will be parsed and validated, rounding to 5 decimal places. A zero-length string may be supplied to indicate 'no rate available'. The server will compare the supplied values with the current values, and if different will notify clients of a delta of change. Only changed fields are notified to clients - unchanged fields are passed as a zero-length string. If a field has changed to zero length, the client will receive the special empty field value in the delta.

public ChangeRate ( string currency, string targetCurrency, string bid, string ask, ITopicUpdaterUpdateContextCallback callback ) : void
currency	string	The base currency.
targetCurrency	string	The target currency.
bid	string	The new bid rate.
ask	string	The new ask rate.
callback	ITopicUpdaterUpdateContextCallback	A callback which will be called to report the outcome. The context in the callback /// will be currency/target currency (e.g. "GBP/USD").
return	void

Close() public method

Close the session.

public Close ( ) : void
return	void

ControlClientUpdatingRecordTopics() public method

Constructor.

public ControlClientUpdatingRecordTopics ( string serverUrl ) : System
serverUrl	string	The server url, for example "ws://diffusion.example.com:80".
return	System

RemoveCurrency() public method

Removes a currency (removes its topics and all subordinate rate topics).

public RemoveCurrency ( string currency, ITopicControlRemoveContextCallback callback ) : void
currency	string	The base currency.
callback	ITopicControlRemoveContextCallback	Reports the outcome.
return	void

RemoveRate() public method

Remove a rate (removes its topic).

public RemoveRate ( string currency, string targetCurrency, ITopicControlRemoveContextCallback callback ) : void
currency	string	The base currency.
targetCurrency	string	The target currency.
callback	ITopicControlRemoveContextCallback	Reports the outcome.
return	void