Class: Query

Inherits:
Plucky::Query
  • Object
show all
Defined in:
lib/yodel/models/core/mongo/query.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(constructor, site, collection, scope = {}) ⇒ Query

construct a default scope for queries on a resource



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# File 'lib/yodel/models/core/mongo/query.rb', line 5

def initialize(constructor, site, collection, scope={})
  @site = site
  @constructor = constructor
  super(collection, scope)
end

Instance Attribute Details

#constructor ⇒ Object (readonly)

Returns the value of attribute constructor.



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# File 'lib/yodel/models/core/mongo/query.rb', line 2

def constructor
  @constructor
end

#site ⇒ Object (readonly)

Returns the value of attribute site.



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# File 'lib/yodel/models/core/mongo/query.rb', line 2

def site
  @site
end

Instance Method Details

#distinct(key) ⇒ Object 



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# File 'lib/yodel/models/core/mongo/query.rb', line 11

def distinct(key)
  record = collection.distinct(key, criteria.to_hash)
end

#find_each(opts = {}) ⇒ Object

TODO: we only cache queries where _id, _site_id, and model are present; _id on its own is a strong enough restriction, so why can’t we cache all queries with id? the query may not match (extra restrictions), but for quries that do match, we should save id-> recrd in cached_records TODO: cache any new records, so they can be matched by single lookups in the future



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# File 'lib/yodel/models/core/mongo/query.rb', line 20

def find_each(opts={})
  if @site
    super.collect do |values|
      record = @site.cached_records[values['_id']]
      record ? record : @constructor.load(@site, values)
    end
  else
    super.collect {|values| @constructor.load(values)}
  end
end

#find_one(opts = {}) ⇒ Object

override find_one to find objects via an identity hash



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# File 'lib/yodel/models/core/mongo/query.rb', line 35

def find_one(opts={})
  unless @site
    document = super
    return nil if document.nil?
    @constructor.load(document)
  else
    query = clone.amend(opts)
  
    # construct the criteria hash, and remove the keys allowed by a cacheable lookup
    criteria_hash = query.criteria.to_hash
    id = criteria_hash[:_id]
    keys = criteria_hash.keys
    keys -= [:_id, :_site_id, :model]
  
    # queries are cacheable if they are looking for a single ID
    cacheable = !id.nil? && id.is_a?(BSON::ObjectId) && keys.empty?
  
    # lookup the record in the cache
    if cacheable
      record = @site.cached_records[id]
      return record unless record.nil?
    end
  
    # lookup failed, so perform a query
    record = query.collection.find_one(criteria_hash, query.options.to_hash)
    if record
      record = @constructor.load(@site, record)
      @site.cached_records[id] = record if cacheable
    end
  
    record
  end
end