WebSocketSender
Sends WebSocket messages to the specified WebSocket server. The first input feature will cause the WebSocketSender to initialize a connection with the specified WebSocket server. The specified Data to Transmit will be sent to the WebSocket server for each input feature of the WebSocketServer, including the first feature that initiated the connection.
Usage Notes
The performance of this transformer is dependent on the amount of memory allocated to the Java Virtual Machine (JVM). The following environment variables allow you to specify memory available to Java Plugins:
- FME_JVM_MIN_HEAP_SIZE: Initial heap size for initializing the JVM. If unset, the default value is 1024K.
- FME32_JVM_MIN_HEAP_SIZE: Same as FME_JVM_MIN_HEAP_SIZE, but applies to 32-bit FME Desktop on Windows, and if set, takes precedence over FME_JVM_MIN_HEAP_SIZE.
These variables must be set in multiples of 1024 and greater than 1 MB. To indicate kilobytes, megabytes, or gigabytes, append k or K, m or M, or g or G respectively. For example, any of these values is acceptable:
6291456
6144k
6m
- FME_JVM_MAX_HEAP_SIZE: Maximum heap size for initializing the JVM. If unset, the default value is 16384K.
- FME32_JVM_MAX_HEAP_SIZE: Same as FME_JVM_MAX_HEAP_SIZE, but applies to 32-bit FME Desktop on Windows, and if set, takes precedence over FME_JVM_MAX_HEAP_SIZE.
These variables must be set in multiples of 1024 and greater than 2 MB. To indicate kilobytes, megabytes, or gigabytes, append k or K, m or M, or g or G respectively. For example, any of these values is acceptable:
83886080
81920k
80m
Note: To pass additional parameters used by FME to the Java Virtual Machine, use the JAVA_TOOL_OPTIONS environment variable.
Input Ports
This transformer accepts any feature.
Output Ports
All input features are directly output through this port after the specified data has been transmitted.
Parameters
The URL of the remote WebSocket server that the WebSocketSender will connect to and transmit WebSocket messages. The default value is ws://localhost:7078. To initiate a secure connection to a WebSocket server using TLS, specify wss://<hostname>:<port>.
If Yes is specified, either explicitly or through a parameter, the WebSocketSender verifies the certificate (or chain of certificates) of the WebSocket server before establishing a connection.
If this optional parameter has a value, then the WebSocketSender will transmit the contents of this parameter to the remote WebSocket server before transmitting the specified data.
To connect to the FME Server WebSocket server, use the following preamble:
{
"ws_op" : "open",
"ws_stream_ids" : ["<STREAMID>", "<STREAMID>", "<STREAMID>", ...]
}
To specify this preamble, click the ellipsis (...) to open the Connection Preamble dialog. Under FME Server WebSocket Preambles, select the Open Public Stream template. Then, specify a ws_stream_ids value.
ws_stream_ids identifies one or more message streams in order for the WebSocket server to associate them with the correct requesting application.
This parameter specifies the data to transmit to the specified WebSocket server. This may be a text value, an attribute value, or the result of an expression.
To send a message to the FME Server WebSocket server, use the following template:
{
"ws_op" : "send",
"ws_msg" : "<MESSAGE>"
}
To specify this template, click the ellipsis (...) to open the Data to Transmit dialog. Under FME Server WebSocket Messages, select the Send Message template. Then, specify a ws_msg value.
Editing Transformer Parameters
Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.
Defining Values
There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.
Using the Text Editor
The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.
Using the Arithmetic Editor
The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.
Conditional Values
Set values depending on one or more test conditions that either pass or fail.
Parameter Condition Definition Dialog
Content
Expressions and strings can include a number of functions, characters, parameters, and more.
When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.
These functions manipulate and format strings. | |
Special Characters |
A set of control characters is available in the Text Editor. |
Math functions are available in both editors. | |
Date/Time Functions | Date and time functions are available in the Text Editor. |
These operators are available in the Arithmetic Editor. | |
These return primarily feature-specific values. | |
FME and workspace-specific parameters may be used. | |
Creating and Modifying User Parameters | Create your own editable parameters. |
Dialog Options - Tables
Transformers with table-style parameters have additional tools for populating and manipulating values.
Row Reordering
|
Enabled once you have clicked on a row item. Choices include:
|
Cut, Copy, and Paste
|
Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. |
Filter
|
Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output. |
Import
|
Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. |
Reset/Refresh
|
Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers. |
Note: Not all tools are available in all transformers.
FME Licensing Level
FME Professional edition and above
FME Community
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