I have multiple endpoints for different vendor's and we are differentiating it based on the userId for similar service operation and routing calls accordingly.
mule-app.properties
userIds=123,124,125
123.service.uri=http://google.com
124.service.url=http://yahoo.com
Can someone tell if there is a way to dynamically refer property using MEL and flowVariable holding userId value?
<flow name="test">
<http:listener config-ref="mylistenerconfig" path="test" doc:name="Request Listener" />
<set-variable variableName="userId" value="#[message.inboundProperties.userId]" />
<set-variable variableName="userServiceUri" value="${flowVars['userId'].service.uri}" />
<logger level="INFO" message="******* serviceUri=#[userServiceUri] ****" />
</flow>
I tried directly referring that value from message.inboundProperties.userId, referring it using a seperate variable - nothing works. Can someone suggest on how to achieve this?
Load the properties files with Spring:
<util:properties id="muleAppProps"
location="classpath*:mule-app.properties" />
Then you can dynamically refer to values in it with:
#[app.registry.muleAppProps[userId + '.service.uri']]
Assuming userId is a flow var that contains a value like "123"
Related
i want to set value in mule-app.properties again. Is there anyway to do this?
Example in mule-app.properties: hostip=192.168.1.116 , in my flow i want to change it become 192.168.1.117
It is very easy. In mule-app.properties you defines properties as you mentioned.
In your flow you use a property placeholder to use the value of that property in a flow or in a configuration. It will be evaluated at deployment time.
Example:
<http:listener-config name="HTTP_Listener_Configuration"
host="${host}" .../>
<flow name="someFlow">
<logger message="host: ${host}" level="INFO" doc:name="Logger" />
I'm trying to connect to SQL Database with some configuration. But based on the input from the API we are supposed to hit different DB.
As of now, we have the code as
<choice doc:name="Check myFlag">
<when expression="#[flowVars.myFlag == 'true']">
<db:stored-procedure config-ref="Database_Configuration_1" doc:name="DB_config_1">
<db:dynamic-query><![CDATA[#[flowVars.callSPName]]]></db:dynamic-query>
</db:stored-procedure>
</when>
<otherwise>
<db:stored-procedure config-ref="Database_Configuration_2" doc:name="DB_config_2">
<db:dynamic-query><![CDATA[#[flowVars.callSPName]]]></db:dynamic-query>
</db:stored-procedure>
</otherwise>
</choice>
Instead of repeating <db:stored-procedure../> twice, is there a way where I can set a flow var with the DB config reference and use it?
Something like,
<db:stored-procedure config-ref="#[flowvars.db_config]" doc:name="DB_config_2">
<db:dynamic-query><![CDATA[#[flowVars.callSPName]]]></db:dynamic-query>
</db:stored-procedure>
In Mule 3, no. config-ref's are evaluated at application startup, not runtime.
In Mule 4 this is possible using Dynamic Configurations: https://docs.mulesoft.com/mule-sdk/1.1/static-dynamic-configs
Potential Mule 3 solutions documented here: https://help.mulesoft.com/s/article/How-to-configure-connector-with-dynamic-parameters
Put the DB call inside a sub-flow and call it from the rest of the flows with a <flow-ref>.
Still learning Mulesoft's Anypoint Studio... I am confused as how will I be able to access raw JSON POST data via the HTTP Listener then use the Choice flow control to execute conditions based on a value from a given JSON index. Anyone can show/tell me how to do this?
The JSON HTTP body will automatically become the payload of your message in Mule probably represented as Stream.
Just for demo purposes, try logging the payload after your http:listener using:
<object-to-string-transformer />
<logger level="INFO" message="#[payload]" />
There best way to query JSON is to transform it to a Map suing the JSON module transformers.
<json:json-to-object-transformer returnClass="java.util.HashMap" />
And then query it using MEL like standard MVEL or Java syntax.
For a JSON document like: {"person" : {"name" : "bob"}}
<logger message="#[payload.person.name]" level="INFO" />
You can use these expressions in your choic router also:
<choice>
<when expression="#[payload.person.name == 'bob']">
do something ...
</when>
</choice>
I'm not sure, how can we extract the flow-name and message-processor Name through MEL. For example I have multiple message processor. For logging, i need to extract the flow Name and Message-processor, so that I can find out transaction has crossed this particular flow and its message processor. Is there any simple way to find out. Please guide me. Please find the screenshot below. Here i need to Extract - set payload and its flowName (flow1)
Thanks in advance.
For mule 3.8+ version onwards #[flow.name] don't work.
Use #[mule:context.serviceName] expression in logger or component to extract the name of the flow
I know this post is old but I have been trying to find a way to do this in MEL for error handling emails.
For the flow name you can use #[exception.event.flowConstruct.name]
for the failing message processor you can use #[exception.failingMessageProcessor].
Both of these work in MEL without the need to use an flowVar.
Please note however, that the failing processor does not always come back with a value but comes back with null, I'm not sure why.
You can extract the flow-name with MEL : #[flow.name]
<flow name="name" doc:name="name">
<http:inbound-endpoint address="http://localhost:8090/resources" doc:name="HTTP" />
<logger message="name of flow: #[flow.name]" level="INFO" doc:name="Logger"/>
<set-payload value="name" doc:name="Set Payload"/>
</flow>
or
flowConstruct.getName() in a Message Processor
Two ways to acthive this (from current flow name)
First one is -
<logger message="Current flowName: #[flow.name]" level="INFO" doc:name="Logger"/>
and the second one is -
<logger message="Current flowName: #[context:serviceName]" level="INFO" doc:name="Logger"/>
In trying to restore the original payload in a message, I ran into this issue that confused me regarding the scope of a mule message. Given the mule config below, I initially assumed that the payload received at the test.Name vm endpoint was going to be restored at the end of the flow (see 1. and 2. in the config):
<mule ...>
<vm:endpoint name="replacePayloadWithFoo.Name"
path="replacePayloadWithFoo.Path" />
<flow name="test">
<vm:inbound-endpoint name="test.Name" path="test.Path"
exchange-pattern="request-response" />
<!-- 1. Down below, I wanted to restore the payload at this point -->
<expression-transformer evaluator="string"
expression="bar" />
<outbound-endpoint ref="replacePayloadWithFoo.Name"
exchange-pattern="request-response" />
<!-- 2. The transformer below does not restore the payload at 1. -->
<expression-transformer evaluator="groovy"
expression="message.originalPayload" />
</flow>
<flow name="replacePayloadWithFoo">
<inbound-endpoint ref="replacePayloadWithFoo.Name"
exchange-pattern="request-response" />
<expression-transformer evaluator="string"
expression="foo" />
</flow>
</mule>
However, it seemed as though the message that entered the test flow ended at the replacePayloadWithFoo outbound endpoint. The transformer at 2. leaves "foo" as the payload.
What's the scope of the mule message?
In passing, the scripting reference documentation indicates that there is a binding for originalPayload in groovy scripts. However, if the transformer at 2. is replaced with
<expression-transformer evaluator="groovy" expression="originalPayload" />
I get an exception:
org.mule.api.expression.RequiredValueException: Expression Evaluator "groovy"
with expression "originalPayload" returned null but a value was required.
What could be the issue?
Thanks
Any outbound interaction, unless performed through an enricher, will affect the current in-flight message. This is why the call to replacePayloadWithFoo replaces the original message with the result of the outbound interaction.
This said, I can not explain the discrepancy between:
<expression-transformer evaluator="groovy" expression="message.originalPayload" />
and:
<expression-transformer evaluator="groovy" expression="originalPayload" />
because they both rely on:
event.getMessage().getPayload()