class Mongoid::Contextual::Mongo
Attributes
@attribute [r] query The Moped
query.
Public Class Methods
Create the new Mongo
context. This delegates operations to the underlying driver - in Mongoid’s case Moped
.
@example Create the new context.
Mongo.new(criteria)
@param [ Criteria
] criteria The criteria.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 263 def initialize(criteria) @criteria, @klass, @cache = criteria, criteria.klass, criteria.options[:cache] @collection = @klass.with(criteria.persistence_options || {}).collection criteria.send(:merge_type_selection) @query = collection.find(criteria.selector) apply_options end
Public Instance Methods
Is the context cached?
@example Is the context cached?
context.cached?
@return [ true, false ] If the context is cached.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 31 def cached? !!@cache end
Get the number of documents matching the query.
@example Get the number of matching documents.
context.count
@example Get the count of documents matching the provided.
context.count(document)
@example Get the count for where the provided block is true.
context.count do |doc| doc.likes > 1 end
@param [ Document
] document A document to match or true if wanting
skip and limit to be factored into the count.
@return [ Integer ] The number of matches.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 54 def count(document = false, &block) return super(&block) if block_given? if document.is_a?(Document) return collection.find(criteria.and(_id: document.id).selector).count end return query.count(document) if document try_cache(:count) { query.count } end
Delete all documents in the database that match the selector.
@example Delete all the documents.
context.delete
@return [ nil ] Nil.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 71 def delete self.count.tap do query.remove_all end end
Destroy all documents in the database that match the selector.
@example Destroy all the documents.
context.destroy
@return [ nil ] Nil.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 86 def destroy destroyed = self.count each do |doc| doc.destroy end destroyed end
Get the distinct values in the db for the provided field.
@example Get the distinct values.
context.distinct(:name)
@param [ String, Symbol
] field The name of the field.
@return [ Array<Object> ] The distinct values for the field.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 105 def distinct(field) query.distinct(klass.database_field_name(field)) end
Iterate over the context. If provided a block, yield to a Mongoid
document for each, otherwise return an enum.
@example Iterate over the context.
context.each do |doc| puts doc.name end
@return [ Enumerator ] The enumerator.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 120 def each(&block) if block_given? selecting do documents_for_iteration.each do |doc| yield_document(doc, &block) end @cache_loaded = true eager_loadable? ? docs : self end else to_enum end end
Do any documents exist for the context.
@example Do any documents exist for the context.
context.exists?
@note We don’t use count here since Mongo
does not use counted
b-tree indexes, unless a count is already cached then that is used to determine the value.
@return [ true, false ] If the count is more than zero.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 146 def exists? return !documents.empty? if cached? && cache_loaded? return @count > 0 if instance_variable_defined?(:@count) try_cache(:exists) do !!(query.dup.select(_id: 1).limit(1).first) end end
Run an explain on the criteria.
@example Explain the criteria.
Band.where(name: "Depeche Mode").explain
@return [ Hash ] The explain result.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 163 def explain query.explain end
Execute the find and modify command, used for MongoDB’s $findAndModify.
@example Execute the command.
context.find_and_modify({ "$inc" => { likes: 1 }}, new: true)
@param [ Hash ] update The updates. @param [ Hash ] options The command options.
@option options [ true, false ] :new Return the updated document. @option options [ true, false ] :remove Delete the first document. @option options [ true, false ] :upsert Create the document if it doesn’t exist.
@return [ Document
] The result of the command.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 183 def find_and_modify(update, options = {}) if doc = FindAndModify.new(collection, criteria, update, options).result Factory.from_db(klass, doc) end end
Get the first document in the database for the criteria’s selector.
@example Get the first document.
context.first
@return [ Document
] The first document.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 197 def first return documents.first if cached? && cache_loaded? try_cache(:first) do with_sorting do with_eager_loading(query.first) end end end
Execute a $geoNear command against the database.
@example Find documents close to 10, 10.
context.geo_near([ 10, 10 ])
@example Find with spherical distance.
context.geo_near([ 10, 10 ]).spherical
@example Find with a max distance.
context.geo_near([ 10, 10 ]).max_distance(0.5)
@example Provide a distance multiplier.
context.geo_near([ 10, 10 ]).distance_multiplier(1133)
@param [ Array<Float> ] coordinates The coordinates.
@return [ GeoNear
] The GeoNear
command.
@since 3.1.0
# File lib/mongoid/contextual/mongo.rb, line 226 def geo_near(coordinates) GeoNear.new(collection, criteria, coordinates) end
Get the last document in the database for the criteria’s selector.
@example Get the last document.
context.last
@return [ Document
] The last document.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 281 def last try_cache(:last) do with_inverse_sorting do with_eager_loading(query.first) end end end
Get’s the number of documents matching the query selector.
@example Get the length.
context.length
@return [ Integer ] The number of documents.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 297 def length @length ||= self.count end
Limits the number of documents that are returned from the database.
@example Limit the documents.
context.limit(20)
@param [ Integer ] value The number of documents to return.
@return [ Mongo
] The context.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 312 def limit(value) query.limit(value) and self end
Invoke the block for each element of Contextual
. Create a new array containing the values returned by the block.
If the symbol field name is passed instead of the block, additional optimizations would be used.
@example Map by some field.
context.map(:field1)
@exmaple Map with block.
context.map(&:field1)
@param [ Symbol
] field The field name.
@return [ Array ] The result of mapping.
# File lib/mongoid/contextual/mongo.rb, line 245 def map(field = nil, &block) if block_given? super(&block) else field = field.to_sym criteria.only(field).map(&field.to_proc) end end
Initiate a map/reduce operation from the context.
@example Initiate a map/reduce.
context.map_reduce(map, reduce)
@param [ String ] map The map js function. @param [ String ] reduce The reduce js function.
@return [ MapReduce
] The map/reduce lazy wrapper.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 327 def map_reduce(map, reduce) MapReduce.new(collection, criteria, map, reduce) end
Pluck the single field values from the database. Will return duplicates if they exist and only works for top level fields.
@example Pluck a field.
context.pluck(:_id)
@note This method will return the raw db values - it performs no custom
serialization.
@param [ String, Symbol
, Array ] field Fields
to pluck.
@return [ Array<Object, Array> ] The plucked values.
@since 3.1.0
# File lib/mongoid/contextual/mongo.rb, line 345 def pluck(*fields) normalized_select = fields.inject({}) do |hash, f| hash[klass.database_field_name(f)] = 1 hash end query.dup.select(normalized_select).map do |doc| if normalized_select.size == 1 doc[normalized_select.keys.first] else normalized_select.keys.map { |n| doc[n] }.compact end end.compact end
Skips the provided number of documents.
@example Skip the documents.
context.skip(20)
@param [ Integer ] value The number of documents to skip.
@return [ Mongo
] The context.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 370 def skip(value) query.skip(value) and self end
Sorts the documents by the provided spec.
@example Sort the documents.
context.sort(name: -1, title: 1)
@param [ Hash ] values The sorting values as field/direction(1/-1)
pairs.
@return [ Mongo
] The context.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 385 def sort(values = nil, &block) if block_given? super(&block) else # update the criteria @criteria = criteria.order_by(values) apply_option(:sort) self end end
Execute a text command against the database.
@example Find documents with the text “phase”
context.text_search("phase")
@param [ String ] query The text search query.
@return [ TextSearch
] The TextSearch
command.
@since 4.0.0
# File lib/mongoid/contextual/mongo.rb, line 406 def text_search(query) TextSearch.new(collection, criteria, query) end
Update the first matching document atomically.
@example Update the first matching document.
context.update({ "$set" => { name: "Smiths" }})
@param [ Hash ] attributes The new attributes for the document.
@return [ nil, false ] False if no attributes were provided.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 420 def update(attributes = nil) update_documents(attributes) end
Update all the matching documents atomically.
@example Update all the matching documents.
context.update({ "$set" => { name: "Smiths" }})
@param [ Hash ] attributes The new attributes for each document.
@return [ nil, false ] False if no attributes were provided.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 434 def update_all(attributes = nil) update_documents(attributes, :update_all) end
Private Instance Methods
Apply the field limitations.
@api private
@example Apply the field limitations.
context.apply_fields
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 485 def apply_fields if spec = criteria.options[:fields] query.select(spec) end end
Apply an option.
@api private
@example Apply the skip option.
context.apply_option(:skip)
@since 3.1.0
# File lib/mongoid/contextual/mongo.rb, line 517 def apply_option(name) if spec = criteria.options[name] query.send(name, spec) end end
Apply the options.
@api private
@example Apply all options.
context.apply_options
@since 3.1.0
# File lib/mongoid/contextual/mongo.rb, line 499 def apply_options apply_fields [ :hint, :limit, :skip, :sort, :batch_size, :max_scan ].each do |name| apply_option(name) end if criteria.options[:timeout] == false query.no_timeout end end
Is the cache fully loaded? Will be true if caching after one full iteration.
@api private
@example Is the cache loaded?
context.cache_loaded?
@return [ true, false ] If the cache is loaded.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 589 def cache_loaded? !!@cache_loaded end
Is the cache able to be added to?
@api private
@example Is the context cacheable?
context.cacheable?
@return [ true, false ] If caching, and the cache isn’t loaded.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 574 def cacheable? cached? && !cache_loaded? end
Get the documents for cached queries.
@api private
@example Get the cached documents.
context.documents
@return [ Array<Document> ] The documents.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 603 def documents @documents ||= [] end
Get the documents the context should iterate. This follows 3 rules:
-
If the query is cached, and we already have documents loaded, use
them.
-
If we are eager loading, then eager load the documents and use
those.
-
Use the query.
@api private
@example Get the documents for iteration.
context.documents_for_iteration
@return [ Array<Document>, Moped::Query ] The docs to iterate.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 623 def documents_for_iteration if cached? && !documents.empty? documents elsif eager_loadable? docs = query.map{ |doc| Factory.from_db(klass, doc) } eager_load(docs) docs else query end end
If we are limiting results, we need to set the field limitations on a thread local to avoid overriding the default values.
@example Execute with selection.
context.selecting do collection.find end
@return [ Object
] The yielded value.
@since 2.4.4
# File lib/mongoid/contextual/mongo.rb, line 646 def selecting begin fields = criteria.options[:fields] Threaded.set_selection(criteria.object_id, fields) unless fields.blank? yield ensure Threaded.delete_selection(criteria.object_id) end end
yield the block given or return the cached value
@param [ String, Symbol
] key The instance variable name
@return the result of the block
@since 3.1.4
# File lib/mongoid/contextual/mongo.rb, line 447 def try_cache(key, &block) unless cached? yield else unless ret = instance_variable_get("@#{key}") instance_variable_set("@#{key}", ret = yield) end ret end end
Update the documents for the provided method.
@api private
@example Update the documents.
context.update_documents(attrs)
@param [ Hash ] attributes The updates. @param [ Symbol
] method The method to use.
@return [ true, false ] If the update succeeded.
@since 3.0.4
# File lib/mongoid/contextual/mongo.rb, line 471 def update_documents(attributes, method = :update) return false unless attributes attributes = Hash[attributes.map { |k, v| [klass.database_field_name(k.to_s), v] }] query.send(method, attributes.__consolidate__(klass)) end
Map the inverse sort symbols to the correct MongoDB values.
@api private
@example Apply the inverse sorting params to the given block
context.with_inverse_sorting
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 551 def with_inverse_sorting begin if spec = criteria.options[:sort] query.sort(Hash[spec.map{|k, v| [k, -1*v]}]) else query.sort(_id: -1) end yield ensure apply_option(:sort) end end
Apply an ascending id sort for use with first
queries, only if no other sorting is provided.
@api private
@example Apply the id sorting params to the given block
context.with_sorting
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 532 def with_sorting begin unless criteria.options.has_key?(:sort) query.sort(_id: 1) end yield ensure apply_option(:sort) end end
Yield to the document.
@api private
@example Yield the document.
context.yield_document(doc) do |doc| ... end
@param [ Document
] document The document to yield to.
@since 3.0.0
# File lib/mongoid/contextual/mongo.rb, line 668 def yield_document(document, &block) doc = document.respond_to?(:_id) ? document : Factory.from_db(klass, document, criteria.object_id) yield(doc) documents.push(doc) if cacheable? end