Alfresco apply category with js to doc

Question

How to apply category to document in Alfresco with javascript?

tried like this:

document.properties["cm:categories"] = "testCat";

UPDATE:

like this I am able to get "root categories" but not "sub categories":

var rootCats =  classification.getRootCategories("cm:generalclassifiable");
document. properties["cm:categories"] = rootCats[3];

this doesnt work:

document. properties["cm:categories"] = rootCats[3][1];

Answer 1

I found it out, if someone need it this is the way how it cana be done

get all root categories [audio, video, image, ...]

var rootCats =  classification.getRootCategories("cm:generalclassifiable");

get subcategories from desired root category -> sub category from "video" [horror, comedy, ...]

var singleCat = rootCats[1].subCategories; 

apply category to document -> apply "horror" to document

doc. properties["cm:categories"] = singleCat[0]; //app

save it

doc.save();