Custom JavaScript Stages Variables and Parameters

JavaScript Stages Variables and Parameters

JavaScript is a lightweight scripting language. The JavaScript in a JavaScript stage is standard ECMAScript. What a JavaScript program can do depends on the container in which it runs. For a JavaScript Query stage, the container is a Fusion query pipeline. The following global pipeline variables are available:

Name	Type	Description
request	Request	The Solr query information.
response	Response	The Solr response information.
ctx	Context	A reference to the container which holds a map over the pipeline properties. Used to update or modify this information for downstream pipeline stages.
collection	String	The name of the Fusion collection being indexed or queried.
solrServer	BufferingSolrServer	The Solr server instance that manages the pipeline’s default Fusion collection. All indexing and query requests are done by calls to methods on this object. See SolrClient for details.
solrServerFactory	SolrClientFactory	The SolrCluster server used for lookups by collection name which returns a Solr server instance for a that collection. For example: var productsSolr = solrServerFactory.getSolrServer("products");.
QueryRequestAndResponse	QueryRequestAndResponse	Returns list of info as a string.

Syntax Variants

JavaScript stages are written using function syntax, which passes variables as function parameters.

Function Syntax

function(request,response) {
   request.addParam("foo", "bar");
}

Important

Function syntax is used for the examples in this document.

Global variable logger

The global variable named logger writes messages to the log file of the server running the pipeline. This variable is truly global and does not need to be declared as part of the function parameter list.

There are 5 methods available, which each take either a single argument (the string message to log) or two arguments (the string message and an exception to log). The five methods are, “debug”, “info”, “warn”, and “error”.