In addition to standard XPath functions, the ESB supports the following custom functions for working with XPath expressions:
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base64Encode() function
The base64Encode function returns the base64-encoded value of the specified string.
Syntax:base64Encode(string)
Next, refer Synapse XPath Variables.
synapse:get-property()Anchor func func
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The The get-property() function function allows any XPath expression used in a configuration to look up information from the current message context. Using the the Property mediator, you can retrieve properties from the message context and header.
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If you provide only the property name without the scope, the default Synapse scope will be used.
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default synapse scope will be used.
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When the result of an XPath evaluation results in a single XML node, the evaluator will return the text content of this node by default (equivalent of doing /root/body/node/text()). If you want to retrieve the node itself, you can configure the Enrich mediator as shown in the following example.
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Synapse scope
When the scope of a property mediator is Synapseis synapse, its value is available throughout both the in sequence and the out sequence. In addition to the user-defined properties, you can retrieve the following special properties from the default scopethe synapse scope.
| Name | Return Value |
| To | Incoming URL as a String, or empty string («») if a To address is not defined. |
| From | From address as a String, or empty string («») if a From address is not defined. |
| Action | SOAP Addressing Action header value as a String, or empty string («») if an Action is not defined. |
| FaultTo | SOAP FaultTo header value as a String, or empty string («») if a FaultTo address is not defined. |
| ReplyTo | ReplyTo header value as a String, or empty string («») if a ReplyTo address is not defined. |
| MessageID | A unique identifier (UUID) for the message as a String, or empty string («») if a MessageID is not defined. This ID is guaranteed to be unique. |
| FAULT | TRUE if the message has a fault, or empty string if the message does not have a fault. |
| MESSAGE_FORMAT | Returns pox, get, soap11, or soap12 depending on the message. If a message type is unknown this returns soap12 |
| OperationName | Operation name corresponding to the message. A proxy service with a WSDL can have different operations. If the WSDL is not defined, ESB defines fixed operations. |
To access a property with the Default synapse scope inside the the mediate() method method of a mediator, you can include the following configuration in a custom mediator created using the the Class Mediator:
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public boolean mediate(org.apache.synapse.MessageContext mc) {
// Available in both in-sequence and out-sequenc
String propValue = (String) mc.getProperty("PropName");
System.out.println("SCOPE_SYNAPSE : " + propValue);
return true;
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axis2 scope
When the scope of a property mediator is axis2, its value is available only throughout the sequence for which the property is defined (e.g., if you add the property to an in sequence, its value will be available only throughout the in sequence). You You can retrieve message context properties within the the axis2 scope scope using the following syntax.
Syntax:get-property('axis2', String propertyName)
To access a property with the the axis2 scope inside the mediate() method of a mediator, you can include the following configuration in a custom mediator created using the Class Mediator:
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axis2-client
This is similar to the Synapse synapse scope. The difference is that it can be accessed inside accessed inside the mediate() method of a mediator by including one of the following configurations in configurations in a custom mediator, created using the Class Mediator:
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public boolean mediate(org.apache.synapse.MessageContext mc) {
org.apache.axis2.context.MessageContext axis2MsgContext;
axis2MsgContext = ((Axis2MessageContext) mc).getAxis2MessageContext();
String propValue = (String) axis2MsgContext.getProperty("PropName");
System.out.println("SCOPE_AXIS2_CLIENT - 1 : " + propValue); |
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propValue = (String) axis2MsgContext.getOptions().getProperty("PropName");
System.out.println("SCOPE_AXIS2_CLIENT - 2: " + propValue);
return true;
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transport scope
When the scope of a property mediator is Transporttransport, it will be added to the transport header of the outgoing message from the ESB. You You can retrieve message context properties within the the transport scope using scope using the following syntax.
Syntax:get-property('transport', String propertyName)
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registry scope
You can retrieve properties within the registry using registry using the following syntax.
Syntax:get-property('registry', String registryPath@propertyName)get-property('registry', String registryPath)
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system scope
You can retrieve Java System properties using properties using the following syntax.
Syntax:get-property('system', String propertyName)
Note: The system scope scope is only available in WSO2 ESB 4.8.0 or and later versions.
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operation scope
You can retrieve a property in the operation context level from the operation scopethe operation scope. The operation scope is used to preserve properties within iterated/cloned message flows. message with the operation scope are preserved in the in sequence even if you have configured your API resources to be sent through the fault sequence when faults exist. A given property with the operation scope only exists in a single request and can be accessed by a single resource. The properties in this scope are passed to the error handler when the FORCE_ERROR_ON_SOAP_FAULT property is set to true. See FORCE_ERROR_ON_SOAP_FAULT section in Generic Properties for more information.
Syntax:get-property('operation', String propertyName)
Next, see Synapse XPath Variables.