Class: Humanoid::Contexts::Mongo
- Defined in:
- lib/humanoid/contexts/mongo.rb
Constant Summary collapse
- AGGREGATE_REDUCE =
"function(obj, prev) { prev.count++; }"
- GROUP_REDUCE =
"function(obj, prev) { prev.group.push(obj); }"
- MAX_REDUCE =
"function(obj, prev) { if (prev.max == 'start') { prev.max = obj.[field]; } " + "if (prev.max < obj.[field]) { prev.max = obj.[field]; } }"
- MIN_REDUCE =
"function(obj, prev) { if (prev.min == 'start') { prev.min = obj.[field]; } " + "if (prev.min > obj.[field]) { prev.min = obj.[field]; } }"
- SUM_REDUCE =
"function(obj, prev) { if (prev.sum == 'start') { prev.sum = 0; } prev.sum += obj.[field]; }"
Instance Attribute Summary collapse
-
#criteria ⇒ Object
readonly
Returns the value of attribute criteria.
Instance Method Summary collapse
-
#aggregate ⇒ Object
Aggregate the context.
-
#count ⇒ Object
Get the count of matching documents in the database for the context.
-
#execute(paginating = false) ⇒ Object
Execute the context.
-
#group ⇒ Object
Groups the context.
-
#grouped(start, field, reduce) ⇒ Object
Common functionality for grouping operations.
-
#initialize(criteria) ⇒ Mongo
constructor
Create the new mongo context.
-
#last ⇒ Object
Return the last result for the
Context
. -
#max(field) ⇒ Object
Return the max value for a field.
-
#min(field) ⇒ Object
Return the min value for a field.
-
#one ⇒ Object
(also: #first)
Return the first result for the
Context
. -
#process_options ⇒ Object
Filters the field list.
-
#sum(field) ⇒ Object
Sum the context.
Methods included from Ids
Methods included from Paging
Constructor Details
#initialize(criteria) ⇒ Mongo
Create the new mongo context. This will execute the queries given the selector and options against the database.
Example:
Humanoid::Contexts::Mongo.new(criteria)
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# File 'lib/humanoid/contexts/mongo.rb', line 96 def initialize(criteria) @criteria = criteria if criteria.klass.hereditary criteria.in(:_type => criteria.klass._types) end end |
Instance Attribute Details
#criteria ⇒ Object (readonly)
Returns the value of attribute criteria.
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# File 'lib/humanoid/contexts/mongo.rb', line 6 def criteria @criteria end |
Instance Method Details
#aggregate ⇒ Object
Aggregate the context. This will take the internally built selector and options and pass them on to the Ruby driver’s group() method on the collection. The collection itself will be retrieved from the class provided, and once the query has returned it will provided a grouping of keys with counts.
Example:
context.aggregate
Returns:
A Hash
with field values as keys, counts as values
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# File 'lib/humanoid/contexts/mongo.rb', line 23 def aggregate klass.collection.group([:fields], selector, { :count => 0 }, AGGREGATE_REDUCE, true) end |
#count ⇒ Object
Get the count of matching documents in the database for the context.
Example:
context.count
Returns:
An Integer
count of documents.
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# File 'lib/humanoid/contexts/mongo.rb', line 36 def count @count ||= klass.collection.find(selector, ).count end |
#execute(paginating = false) ⇒ Object
Execute the context. This will take the selector and options and pass them on to the Ruby driver’s find() method on the collection. The collection itself will be retrieved from the class provided, and once the query has returned new documents of the type of class provided will be instantiated.
Example:
mongo.execute
Returns:
An enumerable Cursor
.
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# File 'lib/humanoid/contexts/mongo.rb', line 52 def execute(paginating = false) cursor = klass.collection.find(selector, ) if cursor @count = cursor.count if paginating cursor else [] end end |
#group ⇒ Object
Groups the context. This will take the internally built selector and options and pass them on to the Ruby driver’s group() method on the collection. The collection itself will be retrieved from the class provided, and once the query has returned it will provided a grouping of keys with objects.
Example:
context.group
Returns:
A Hash
with field values as keys, arrays of documents as values.
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# File 'lib/humanoid/contexts/mongo.rb', line 75 def group klass.collection.group( [:fields], selector, { :group => [] }, GROUP_REDUCE, true ).collect do |docs| docs["group"] = docs["group"].collect do |attrs| Humanoid::Factory.build(klass, attrs) end docs end end |
#grouped(start, field, reduce) ⇒ Object
Common functionality for grouping operations. Currently used by min, max and sum. Will gsub the field name in the supplied reduce function.
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# File 'lib/humanoid/contexts/mongo.rb', line 200 def grouped(start, field, reduce) collection = klass.collection.group( nil, selector, { start => "start" }, reduce.gsub("[field]", field), true ) collection.empty? ? nil : collection.first[start.to_s] end |
#last ⇒ Object
Return the last result for the Context
. Essentially does a find_one on the collection with the sorting reversed. If no sorting parameters have been provided it will default to ids.
Example:
context.last
Returns:
The last document in the collection.
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# File 'lib/humanoid/contexts/mongo.rb', line 114 def last opts = sorting = opts[:sort] sorting = [[:_id, :asc]] unless sorting opts[:sort] = sorting.collect { |option| [ option[0], option[1].invert ] } attributes = klass.collection.find_one(selector, opts) attributes ? Humanoid::Factory.build(klass, attributes) : nil end |
#max(field) ⇒ Object
Return the max value for a field.
This will take the internally built selector and options and pass them on to the Ruby driver’s group() method on the collection. The collection itself will be retrieved from the class provided, and once the query has returned it will provided a grouping of keys with sums.
Example:
context.max(:age)
Returns:
A numeric max value.
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# File 'lib/humanoid/contexts/mongo.rb', line 139 def max(field) grouped(:max, field.to_s, MAX_REDUCE) end |
#min(field) ⇒ Object
Return the min value for a field.
This will take the internally built selector and options and pass them on to the Ruby driver’s group() method on the collection. The collection itself will be retrieved from the class provided, and once the query has returned it will provided a grouping of keys with sums.
Example:
context.min(:age)
Returns:
A numeric minimum value.
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# File 'lib/humanoid/contexts/mongo.rb', line 159 def min(field) grouped(:min, field.to_s, MIN_REDUCE) end |
#one ⇒ Object Also known as: first
Return the first result for the Context
.
Example:
context.one
Return:
The first document in the collection.
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# File 'lib/humanoid/contexts/mongo.rb', line 172 def one attributes = klass.collection.find_one(selector, ) attributes ? Humanoid::Factory.build(klass, attributes) : nil end |
#process_options ⇒ Object
Filters the field list. If no fields have been supplied, then it will be empty. If fields have been defined then _type will be included as well.
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# File 'lib/humanoid/contexts/mongo.rb', line 213 def fields = [:fields] if fields && fields.size > 0 && !fields.include?(:_type) fields << :_type [:fields] = fields end .dup end |
#sum(field) ⇒ Object
Sum the context.
This will take the internally built selector and options and pass them on to the Ruby driver’s group() method on the collection. The collection itself will be retrieved from the class provided, and once the query has returned it will provided a grouping of keys with sums.
Example:
context.sum(:age)
Returns:
A numeric value that is the sum.
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# File 'lib/humanoid/contexts/mongo.rb', line 194 def sum(field) grouped(:sum, field.to_s, SUM_REDUCE) end |