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>.
Related
How do check if the variable exist in Mule 3.2?
How create or replace a variable?
My Flow Exception is
<choice doc:name="Choice">
<when expression="#[myVar==null]">
<processor-chain>
<set-variable variableName="myVar" value="value1" doc:name="myVar"/>
</processor-chain>
</when>
<otherwise>
<processor-chain>
<set-variable variableName="myVar" value="#[variable:myVar]" doc:name="myVar"/>
</processor-chain>
</otherwise>
</choice>
"myVar==null" does not work
if the variable is an invocation variable please try
flowVars['myVar'] == null
Worst case scenario you could do:
message.getProperty('myVar', org.mule.api.transport.PropertyScope.INVOCATION).
Please notice the scope is an enum so you should provide the canonical in a MEL expression.
HTH
You can use this MEL to print in log or use in Choice component
#[message.invocationProperties('myVar')] == null
There is a component "Message Property" which will help you remove or replace or create Mule message properties. You should use that to perform your operation.
To best find it use keyword "propert" in the search of pallets in the Mule studio and explore the various components there to suit your needs.
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>
The message enricher documentation uses a term "variable" for example
<flow name="orderProcessingFlow">
<inbound-endpoint ref="orderEndpoint"/>
<enricher target="#[variable:state]">
<outbound-endpoint ref="stateLookup"/>
</enricher>
<outbound-endpoint ref="orderStep2"/>
</flow>
I did not find any documentation on that keyword, I can figure out it basically adds a flow variable, but is there anything more to it ? (without keyword variable you get a exception)
Also none of the examples in the documentation refer to enriching "message headers" -- My assumption is that message headers implies outbound properties is that correct ?
If the same flow were to add a outbound property how would it look (this works based on my tests)
<flow name="orderProcessingFlow">
<inbound-endpoint ref="orderEndpoint"/>
<enricher target="#[message.outboundProperties.var]">
<outbound-endpoint ref="stateLookup"/>
</enricher>
<outbound-endpoint ref="orderStep2"/>
</flow>
#[variable:state] is the old expression syntax, it's deprecated and replaced by MEL since 3.3. I think the MEL equivalent is #[flowVars.state]
Similarly, message "headers" is obsolete lingo. You have message properties with different scopes (inbound, outbound, flow/invocation and session).
And yes the only properties you can set in a flow are outbound properties (inbound ones are set by endpoints).
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 mule flow I need to compare the last two params from an input string message
2012-04-30,2012-05-30,1,5
And if param1(1) <= param2(5), I need perform jms:outbound-endpoint.
Is there a standard choice element to do it? Could you please provide example.
While using mule 3.2.x your best option is to use the groovy evaluator and use a choice router that look like the following
<when expression="#[groovy:payload.split(',')[2] <= payload.split(',')[3] ]">
<processor-chain>
<jms:outbound-endpoint queue="out" doc:name="JMS"/>
</processor-chain>
</when>
Otherwise if you are willing to upgrade to Mule 3.3.0 you can take advantage of the new Mule Expression Language that allows to do the same without the need of the groovy operator
you can also use splitter and split on the basis of ',' and then have the compare logic for the params
You need not use Groovy for this. You can directly apply the split() function on payload.
<when expression="#[payload.split(',')[2]<=payload.split(',')[3]]">
<processor-chain doc:name="Processor Chain">
<jms:outbound-endpoint queue="data" connector-ref="Active_MQ"doc:name="JMS"/>
</processor-chain>
</when>
Apart from expression filter you can also use choice flow control. Capture the 2 values to be compared in a flowvars and use below expression in when condition of choice flow control.
[flowVars.param1 <= flowVars.param1]
Giving below the link for more information.
https://docs.mulesoft.com/mule-user-guide/v/3.7/choice-flow-control-reference
you can take advantage of the new Mule Expression Language that allows to do the same without the need of the groovy operator