Parsing CSV file and get a value of the filed from it

Question

Question regarding Mule 4 and DWL syntax. I have a file listener that is expecting a csv file.
let say the file is in this format
value1, value2, value3, value4
Then I have a "var" message processor and in there need to assign the value of value3 (third field) to a variable. How can I dod that? Your help is appreciated.

Answer 1

If you only have the one line you can access the first row using index 0: [0], then access the third field using index 2 [2]. Indexes start at 0.

Note, if your CSV does NOT have a header row, make sure to add this to the file:listener outputMimeType="application/csv;header=false" to let dw know there is no header row:

<flow name="csv">
        <file:listener directory="/path/to/dir"  outputMimeType="application/csv;header=false" >
            <scheduling-strategy >
                <fixed-frequency frequency="100000" />
            </scheduling-strategy>
        </file:listener>

        <logger level="INFO" message="#[payload]" />
        <set-variable value="#[output application/java --- payload[0][2] as String]" variableName="myVar" />

        <logger level="INFO" message="#[vars.myVar]" />
    </flow>

Also note you can use the transform component to set-variables also for more complex transformations where better formatting is required:

<ee:transform>
            <ee:variables>
                <ee:set-variable variableName="myVar" ><![CDATA[%dw 2.0
output application/java
---
payload[0][2] as String]]></ee:set-variable>
            </ee:variables>
        </ee:transform>