Sling Pipes

Sling Pipes is a new tool which can extract, transform and load the underlying content using set of configuration. Here you can load a resource tree based on a pipe, a pipe can have an input a reader/writer or container pipes.

A pipe is nothing but a jcr node which has some distinctive characteristics.

·         sling:resourceType property – Must be a pipe type registered by the plumber

·         name property – Used in bindings as an id

·         path property – Defines pipe’s input

·         expr property – Expression through which the pipe will execute

·         additionalBinding node – Node you can add to set “global” bindings (property=value) in pipe execution

·         additionalScripts – Multivalue property to declare scripts that can be reused in expressions

·         conf child node – Contains addition configuration of the pipe

There are three types of pipe container pipe which acts as a container for other two types of pipe reader and writer.

Please refer the following links for more sling pipes  ,link1 and link2 for more details , let’s think of use case where you want to update certain nodes with allowedProperty= true which satisfies a certain query , this can be achieved by writing some custom code and the alternative is use writer sling pipe the steps are described as below.

Step1. Create a node of type sling:folder with the resourceType as slingPipes/container for eg "/etc/samplepipes/xpath1Write" and name it as xpath1Write

Step2 .Create a node named conf of type sling:OrderedFolder under the node created in step1

Step 3. Create a node named xpath with the resouceType as slingPipes/xpath

Step4. Add property named expr of type String and value "/jcr:root/content/geometrixx/en//element(*, nt:unstructured)[fn:name() = 'image']

“which is an xpath query to get all nodes which has image .

Step 5: Create a writer sling pipe, create a  orderFolder node named write of resourceType "slingPipes/write" 

Step 6:Create a node nt:unstructured node named as conf having the property to update here in our case it is "allowedProperty" of type boolean and value true

Once  you follow the above steps the node structure should look like as below.

Once you have done the changes  time to execute the sling pipes as this is write operation so we must use POST request , we can use curl command to update all the nodes , on running the below command

curl -u admin:admin -X POST http://localhost:4502/etc/samplepipes/xpath1Write.json

We get all nodes modified with required property which has been set as a part of sling write pipes.