DdeClient public instance methods

coldLink:format:

Tells the server to disconnect a link.

item

A String identifying the item to disconnect.

format

A String identifying the format of the item to be disconnected.

Return value:

true

The server disconnected the link to the item.

false

The server cannot disconnect the link to the item.

 

connect:topic:

Attempts to connect to a DDE server identified by applicationString with topic topicString. Only the first server to acknowledge is connected. All other connections are terminated. Processing of the connections from the servers happens elsewhere. Answers true if the receiver is connected. Otherwise, answer false.

applicationString

A String identifying the name of the application to connect to.

topicString

A String identifying the name of the application's topic to be connected to.

Return value:

true

The connection was made.

false

The connection cannot be made.

 

execute:

Asks the server to run a command string on behalf of the receiver. Answers true if the server ran the command. Otherwise, answers false.

commandString

A String identifying the command to be run by the server.

Return value:

true

The server runs the command.

false

The server cannot run the command.

 

free

Frees any allocated resources. After this message is sent, the receiver is invalid and cannot be used.

 

hotLink:format:

Attempts to create a link to item so that when the item is updated by the server, a callback (DdeNdataCallback) is called, sending the data as part of the callback.

Answers a Boolean indicating whether the server accepted the request.

item

A String identifying the name of the item to hotlink to.

format

A String identifying the format that the data should be in when it comes back from the server.

Return value:

true

The item is hotlinked.

false

The item cannot be hotlinked.

 

queryAll

Queries all servers for all topics. Answers a Dictionary of Sets with the application name as the key and a Set of topic names as the value.

 

queryServersFor:

Queries all servers for a topic. Answers a Set of applications (instances of String) that handle the topic.

topicString

A String naming the topic of interest.

 

queryTopicsFrom:

Queries a server for all topics that it supports. Answers a Set of topics (instances of String) that are handled by the application.

applicationString

A String identifying the name of the server.

 

requestData:format:

Requests data from the server.

item

A String identifying the name of the item to retrieve.

format

A String identifying the format that the data should be in when it comes back from the server.

Return value:

nil

The server could not provide the data.

String

The format requested was 'String' and, therefore, the data from the server is a Smalltalk String.

ByteArray

The format requested was something other than 'String' and therefore the data from the server is a ByteArray.

 

send:value:format:

Sends data to the server. This is a DDE "poke".

item

A String identifying the name of the item to send to the server.

value

The data that is to be sent to the client. If the format is 'String,' the value must also be a Smalltalk String. Otherwise, value must be a ByteArray.

format

A String identifying the format that the data should be in when it is returned from the server.

Return value:

true

The server accepts the data.

false

The server rejects the data or a time out has occurred.

 

warmLink:format:

Attempts to create a link to item so that when the item is updated by the server, a callback (DdeNdataCallback) is called. The data is not sent as part of the callback.

item

A String identifying the item to disconnect.

format

A String identifying the format of the item to be disconnected.

Return value:

true

The item is warmlinked.

false

Item cannot be warmlinked.

When the ENVY/Image DDE Examples configuration map is loaded, one of the applications that is loaded is DdeExamples. This application contains a number of classes that facilitate the testing of the DDE classes. The loading of this application requires that the ENVY/Swapper configuration map be loaded.