Example Groovy update script

addTagUpdateScript

//import org.apache.lucene.codecs.bloom.FuzzySet;

// Extract the doc source to a field
doc = ctx._source;

// Convert basic array into map for ease of manipulation
tagMap = doc.tags.collectEntries{[it.tag, it]};


// Patch the new tags into the data structure, adding one to a usercount
for (usertag in usertags){
    def tag = tagMap.get(usertag);
    if(tag == null){
        // create new tag
        tag = ["tag":usertag, "usercount":1];
        tagMap.put(usertag, tag);
    } else{
        // Existing tag
        if(tag.usercount == null){
            tag.usercount = 1;
        } else {
            tag.usercount++;
        }
    }
}

//This won't work because of sandboxing
//FuzzySet users=FuzzySet.createSetBasedOnMaxMemory(500);

//TODO use HyperLogLog structure rather than count to prevent double-counting?
//def bytes=userid.getBytes();
//hash=MurmurHash2.hash32(bytesRef.bytes, 0, bytes.length);
//println(hash);

// Store the modified map's values back as array.
doc.tags = tagMap.values();

exampleDocBeingUpdated

{
	"_index": "bookmarks",
	"_type": "bookmark",
	"_id": "http://www.bbc.co.uk/news/world-asia-27807157",
	"_source": {
		"description": "Singapore's Marina Bay Sands casino has banned shark fin, the latest in a series of boycotts around the region.",
		"image": "http://news.bbcimg.co.uk/media/images/75469000/jpg/_75469430_hi022417700.jpg",
		"title": "BBC News - Singapore casino bans shark fin",
		"tags": [
			{
				"_index": "bookmarks",
				"_id": "sharks",
				"highlight": {
					"description": [
						" <em>shark</em> fin, the latest in a series of boycotts around the region."
					]
				},
				"tag": "sharks",
				"usercount": 5
			}
		]
	}
}

exampleParamsToScript

{
    "userid": "hf74hs238adghs023j",
	"usertags": [
		"sharks",
		"casino"
	]
}