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  1. CouchDB
  2. COUCHDB-1188

View query option defaults

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Details

    • New Feature
    • Status: Closed
    • Minor
    • Resolution: Won't Fix
    • 1.0.2
    • None
    • JavaScript View Server
    • New Contributors Level (Easy)

    Description

      Currently, it's necessary to have intimate-ish knowledge of the inner workings of a view when calling it, e.g.:

      http://localhost:5984/mydb/_design/burp/_view/count-laser-beams?group_level=2

      If the group level was different, the results returned by the view might be useless.

      Other good examples are "include_docs", "inclusive_end" or "descending". For instance, views that pull in foreign documents by emitting {_id: ...} as a value will only produce useful results when called with "include_docs" set to true.

      I'd suggest a feature where inside a view definition, a new key "query_defaults" alongside "map" or "reduce" contains a hash map of query option keys and values that will be used when calling the view unless one of the pre-defined options is passed as a query argument, in which case the explicitly given query argument would take precedence.

      Example:

      "views": {
      "talks-by-room": {
      "map": "function(doc) {\n\tif(doc.type == 'talk' && doc.date_start) {\n\t\temit([doc.room, doc.date_start, 0], doc.name);\n\t\tif(doc.speaker) {\n\t\t\temit([doc.room, doc.date_start, 1], {_id: doc.speaker});\n\t\t}\n\t}\n};",
      "query_defaults":

      { "include_docs": true }

      }
      }

      http://localhost:5984/couchcamp/_design/burp/_view/talks-by-room would be run with include_docs=true, but the doc inclusion could be suppressed by requesting http://localhost:5984/couchcamp/_design/burp/_view/talks-by-room?include_docs=false

      Alternative names for the new key are "query_options" or "query_option_defaults". Whilst I prefer "query_options", I think "query_defaults" will be the better choice as it underlines the nature of the functionality - namely, that the options defined therein may be overridden by the caller.

      Someone on the dev list suggested to use _rewrite, but the idea is that the defaults also apply when invoking a list function. So you'd need two rewrites, one for the view if you want to call it standalone, and one for the list function. And then you'd still have the issue that the behavior of the view is changed by the rewrite, which is confusing to anyone looking at the view code - you have to look at the rewrite as well to get the whole picture. Not good.

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            Unassigned Unassigned
            dzuelke David Zülke
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            Dates

              Created:
              Updated:
              Resolved: