Class: WCC::Contentful::Store::Base Abstract

Inherits:
Object
  • Object
show all
Includes:
Interface
Defined in:
lib/wcc/contentful/store/base.rb

Overview

This class is abstract.

At a minimum subclasses should override Interface#find, #execute, #set, and ##delete. As an alternative to overriding set and delete, the subclass can override #index. Index is called when a webhook triggers a sync, to update the store.

This is the base class for stores which implement #index, and therefore must be kept up-to-date via the Sync API. To implement a new store, you should include the rspec_examples in your rspec tests for the store. See spec/wcc/contentful/store/memory_store_spec.rb for an example.

Direct Known Subclasses

MemoryStore, PostgresStore

Constant Summary

Constants included from Interface

Interface::INTERFACE_METHODS

Instance Method Summary collapse

Methods included from Interface

#find

Constructor Details

#initialize(configuration = nil) ⇒ Base

Returns a new instance of Base.



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# File 'lib/wcc/contentful/store/base.rb', line 20

def initialize(configuration = nil)
  @configuration = configuration || WCC::Contentful.configuration
end

Instance Method Details

#delete(_id) ⇒ Object

This method is abstract.

Removes the entry by ID from the store.

Raises:

  • (NotImplementedError) 


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# File 'lib/wcc/contentful/store/base.rb', line 32

def delete(_id)
  raise NotImplementedError, "#{self.class} does not implement #delete"
end

#ensure_hash(val) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/wcc/contentful/store/base.rb', line 115

def ensure_hash(val)
  raise ArgumentError, 'Value must be a Hash' unless val.is_a?(Hash)
end

#execute(_query) ⇒ Object

This method is abstract.

Executes a WCC::Contentful::Store::Query object created by #find_all or #find_by. Implementations should override this to translate the query’s conditions into a query against the datastore.

For a very naiive implementation see WCC::Contentful::Store::MemoryStore#execute

Raises:

  • (NotImplementedError) 


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# File 'lib/wcc/contentful/store/base.rb', line 42

def execute(_query)
  raise NotImplementedError, "#{self.class} does not implement #execute"
end

#find_all(content_type:, options: nil) ⇒ Query

Finds all entries of the given content type. A content type is required.

Subclasses may override this to provide their own query implementation,

or else override #execute to run the query after it has been parsed.

Parameters:

  • content_type (String) —

    The ID of the content type to search for.

  • options (Hash) (defaults to: nil) —

    An optional set of additional parameters to the query defining for example include depth. Not all store implementations respect all options.

Returns:

  • (Query) —

    A query object that exposes methods to apply filters



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# File 'lib/wcc/contentful/store/base.rb', line 106

def find_all(content_type:, options: nil)
  Query.new(
    self,
    content_type: content_type,
    options: options,
    configuration: @configuration
  )
end

#find_by(content_type:, filter: nil, options: nil) ⇒ Object

Finds the first entry matching the given filter. A content type is required.

Parameters:

  • content_type (String) —

    The ID of the content type to search for.

  • filter (Hash) (defaults to: nil) —

    A set of key-value pairs defining filter operations. See WCC::Contentful::Store::Base::Query

  • options (Hash) (defaults to: nil) —

    An optional set of additional parameters to the query defining for example include depth. Not all store implementations respect all options.



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# File 'lib/wcc/contentful/store/base.rb', line 91

def find_by(content_type:, filter: nil, options: nil)
  # default implementation - can be overridden
  q = find_all(content_type: content_type, options: { limit: 1 }.merge!(options || {}))
  q = q.apply(filter) if filter
  q.first
end

#index(json) ⇒ Object

Processes a data point received via the Sync API. This can be a published entry or asset, or a ‘DeletedEntry’ or ‘DeletedAsset’. The default implementation calls into #set and #delete to perform the appropriate operations in the store.



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# File 'lib/wcc/contentful/store/base.rb', line 56

def index(json)
  # This implementation assumes that #delete and #set are individually thread-safe.
  # No mutex is needed so long as the revisions are accurate.
  # Subclasses can override to do this in a more performant thread-safe way.
  # Example: postgres_store could do this in a stored procedure for speed
  prev =
    case type = json.dig('sys', 'type')
    when 'DeletedEntry', 'DeletedAsset'
      delete(json.dig('sys', 'id'))
    else
      set(json.dig('sys', 'id'), json)
    end

  if (prev_rev = prev&.dig('sys', 'revision')) &&
      (next_rev = json.dig('sys', 'revision')) &&
      (next_rev < prev_rev)
    # Uh oh! we overwrote an entry with a prior revision.  Put the previous back.
    return index(prev)
  end

  case type
  when 'DeletedEntry', 'DeletedAsset'
    nil
  else
    json
  end
end

#index? ⇒ Boolean

Returns true if this store can persist entries and assets which are retrieved from the sync API.

Returns:

  • (Boolean) 


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# File 'lib/wcc/contentful/store/base.rb', line 48

def index?
  true
end

#set(_id, _value) ⇒ Object

This method is abstract.

Sets the value of the entry with the given ID in the store.

Raises:

  • (NotImplementedError) 


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# File 'lib/wcc/contentful/store/base.rb', line 26

def set(_id, _value)
  raise NotImplementedError, "#{self.class} does not implement #set"
end