[xwiki-devs] [Proposal] Implement "distinct" in XWQL short queries through a QueryFilter

Hi devs, while replacing calls to xwiki#searchDocuments by calls to the query manager script service I ran into the following query manager issue: http://jira.xwiki.org/browse/XWIKI-7273 (XWQL short form queries should distinct on document fullname.) I think we could use the recent QueryFilter mechanism to handle the addition of the "distinct" in the select statement. https://github.com/xwiki/xwiki-platform/blob/master/xwiki-platform-core/xwi… QueryFilters allow to: - transform queries depending on a dynamic parameter (for example the user preferences in HiddenDocumentFilter) - transform the select part of a short query, without requiring programming rights Here's an example of what it could look like from a velocity script: ----------------------------------------------------8<---------------------------------------------------- #set($query = $services.query.xwql("").addFilter("unique").addFilter("hidden")) ----------------------------------------------------8<---------------------------------------------------- Note that in the future we could decide that the Query wrapper we use in the QueryManagerScriptService (ScriptQuery) have the "unique" filter by default + a way to remove it from the script. I wasn't expecting us to consider using multiple filters when I added the new APIs in Query (4.0RC1). If we agree that a QueryFilter would be a nice way to handle this, I'd like to break those API before we release 4.0: ----------------------------------------------------8<---------------------------------------------------- - Query setFilter(QueryFilter filter); + Query addFilter(QueryFilter filter); - QueryFilter getFilter(); + List<QueryFilter> getFilters(); ----------------------------------------------------8<---------------------------------------------------- WDYT ? JV.