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CreateContext Method

Example

Applies to

TRPCBroker component

Declarat..."

2015-07-05T13:50:39Z

Created page with "<h2>CreateContext Method</h2> Example <h3>Applies to</h3> TRPCBroker component <h3>Declarat..."

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<h2>CreateContext Method</h2>
[[RPC_HELP_TRPCBroker_CreateContext_Method_Example|Example]]

<h3>Applies to</h3>
[[RPC_HELP_TRPCBroker|TRPCBroker]] component

<h3>Declaration</h3>
function CreateContext(strContext: string): boolean;

<h3>Description</h3>
You can use the '''CreateContext''' method of the [[RPC_HELP_TRPCBroker|TRPCBroker]] component to create a context for your application. To create context, pass an option name in the strContext parameter. If the function returns True, a context was created, and your application can use all [[RPC_HELP_RPCs|RPC]] entered in the option's RPC multiple. If the [[RPC_HELP_TRPCBroker|TRPCBroker]] component is not connected at the time context is created, a connection will be established. If for some reason a context could not be created, the '''CreateContext''' method will return False.

Since context is nothing more than a client/server "B"-type option in the OPTION file (#19), standard MenuMan security is applied in establishing a context. Therefore, a context option can be granted to user(s) exactly the same way as regular options are done using MenuMan. Before any RPC can run, it must have a context established for it to on the VistA M Server. Thus, all RPCs must be registered to one or more "B"-type option(s). This plays a major role in Broker security.

A context cannot be established for the following reasons:
* The user has no access to that option.
* The option is temporarily out of order.

An application can switch from one context to another as often as it needs to. Each time a context is created the previous context is overwritten.

NOTE: See the [[RPC_HELP_TRPCBroker_CurrentContext|CurrentContext]] property for information about saving off the current context in order to temporarily create a different context and then restore the previous context.

NOTE: See [[RPC_HELP_RPC_Limits|RPC Limits]] for information about the size of parameters and results that can be passed to and returned from the [[RPC_HELP_TRPCBroker|TRPCBroker]] component.

NOTE: Whenever the Broker makes a call to the VistA M Server, if the cursor is crDefault, the cursor is automatically changed to the hourglass symbol as seen in other Microsoft-compliant software. If the application has already modified the cursor from crDefault to something else, the Broker will not change the cursor.

NOTE: For a demonstration that creates an application context, please run the [[RPC_HELP_BrokerExampleEXE|BrokerExampleEXE]] located in the ..\BDK32\Samples\BrokerEx directory.

RPC HELP TRPCBroker CreateContext Method - Revision history

Kdtop: Created page with "

CreateContext Method

Applies to

Declarat..."