Class: RedfishClient::Resource

Inherits:
Object
  • Object
show all
Defined in:
lib/redfish_client/resource.rb

Overview

Resource is basic building block of Redfish client and serves as a container for the data that is retrieved from the Redfish service.

When we interact with the Redfish service, resource will wrap the data retrieved from the service API and offer us dot-notation accessors for values stored.

Resource will also load any sub-resource on demand when we access it. For example, if we have a root Redfish resource stored in root, accessing root.SessionService will automatically fetch the appropriate resource from the API.

In order to reduce the amount of requests being sent to the service, resource also caches responses for later reuse. If we would like to get fresh values from the service, #reset call will flush the cache, causing next access to retrieve fresh data.

Direct Known Subclasses

Root

Defined Under Namespace

Classes: NoODataId

Instance Method Summary collapse

Constructor Details

#initialize(connector, oid: nil, content: nil) ⇒ Resource

Create new resource.

Resource can be created either by passing in OpenData identifier or supplying the content (hash). In the first case, connector will be used to fetch the resource data. In the second case, resource only wraps the passed-in hash and does no fetching.

Parameters:

  • connector (RedfishClient::Connector) —

    connector that will be used to fetch the resources

  • oid (String) (defaults to: nil) —

    OpenData id of the resource

  • content (Hash) (defaults to: nil) 


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# File 'lib/redfish_client/resource.rb', line 38

def initialize(connector, oid: nil, content: nil)
  if oid
    resp = connector.get(oid)
    @content = JSON.parse(resp.data[:body])
    @content["@odata.id"] = oid
    @headers = resp.data[:headers]
  else
    @content = content
  end

  @cache = {}
  @connector = connector
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(symbol, *args, &block) ⇒ Object

Convenience access for resource data.

Calling resource.Value is exactly the same as resource["Value"]. The only difference is that accessing non-existent field will raise NoMethodError instead of KeyError as [] method does.



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# File 'lib/redfish_client/resource.rb', line 89

def method_missing(symbol, *args, &block)
  name = symbol.to_s
  key?(name) ? self[name] : super
end

Instance Method Details

#[](attr) ⇒ Object

Access resource content.

This function offers a way of accessing resource data in the same way that hash exposes its content.

In addition to accessing values associated with keys, this function can also be used to access members of collection by directly indexing into Members array. This means that res["Members"][3] can be shortened into res[3].

Accessing non-existent or indexing non-collection resource key will raise KeyError. Accessing invalid index will raise IndexError.

Parameters:

  • attr (String, Integer) —

    key or index for accessing data

Returns:

  • associated value



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# File 'lib/redfish_client/resource.rb', line 67

def [](attr)
  if attr.is_a?(Integer)
    raise(KeyError, "Not a collection.") unless key?("Members")
    cache("Members").fetch(attr)
  else
    cache(attr)
  end
end

#delete ⇒ Excon::Response

Issue a DELETE requests to the endpoint of the resource.

If the resource has no @odata.id field, NoODataId error will be raised, since deleting non-networked resources makes no sense and probably indicates bug in library consumer.

Returns:

  • (Excon::Response) —

    response

Raises:

  • (NoODataId) —

    resource has no OpenData id



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# File 'lib/redfish_client/resource.rb', line 164

def delete
  @connector.delete(get_path("@odata.id", nil))
end

#key?(name) ⇒ Boolean

Test if resource contains required key.

Parameters:

  • name (String, Symbol) —

    key name to test

Returns:

  • (Boolean) —

    inclusion test result



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# File 'lib/redfish_client/resource.rb', line 80

def key?(name)
  @content.key?(name.to_s)
end

#patch(field: "@odata.id", path: nil, payload: nil) ⇒ Excon::Response

Issue a PATCH requests to the selected endpoint.

Works exactly the same as the #post method, but issued a PATCH request to the server.

Parameters:

  • field (String, Symbol) (defaults to: "@odata.id") —

    path lookup field

  • path (String) (defaults to: nil) —

    path to patch

  • payload (Hash<String, >) (defaults to: nil) —

    data to send

Returns:

  • (Excon::Response) —

    response

Raises:

  • (NoODataId) —

    resource has no OpenData id



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# File 'lib/redfish_client/resource.rb', line 152

def patch(field: "@odata.id", path: nil, payload: nil)
  @connector.patch(get_path(field, path), payload ? payload.to_json : "")
end

#post(field: "@odata.id", path: nil, payload: nil) ⇒ Excon::Response

Issue a POST requests to the selected endpoint.

By default, POST request will be sent to the path, stored in @odata.id field. Source field can be changed by specifying the field parameter when calling this function. Specifying the path argument will bypass the field lookup altogether and POST directly to the requested path.

In order to avoid having to manually serialize data to JSON, this function call takes Hash as a payload and encodes it before sending it to the endpoint.

If the resource has no lookup field, NoODataId error will be raised, since posting to non-networked resources makes no sense and probably indicates bug in library consumer.

Parameters:

  • field (String, Symbol) (defaults to: "@odata.id") —

    path lookup field

  • path (String) (defaults to: nil) —

    path to post to

  • payload (Hash<String, >) (defaults to: nil) —

    data to send

Returns:

  • (Excon::Response) —

    response

Raises:

  • (NoODataId) —

    resource has no OpenData id



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# File 'lib/redfish_client/resource.rb', line 138

def post(field: "@odata.id", path: nil, payload: nil)
  @connector.post(get_path(field, path), payload ? payload.to_json : "")
end

#raw ⇒ Hash

Access raw JSON data that resource wraps.

Returns:

  • (Hash) —

    wrapped data



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# File 'lib/redfish_client/resource.rb', line 107

def raw
  @content
end

#reset ⇒ Object

Clear the cached sub-resources. Next sub-resource access will repopulate the cache.



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# File 'lib/redfish_client/resource.rb', line 100

def reset
  @cache = {}
end

#respond_to_missing?(symbol, include_private = false) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/redfish_client/resource.rb', line 94

def respond_to_missing?(symbol, include_private = false)
  key?(symbol.to_s) || super
end

#to_s ⇒ String

Pretty-print the wrapped content.

Returns:

  • (String) —

    JSON-serialized raw data



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# File 'lib/redfish_client/resource.rb', line 114

def to_s
  JSON.pretty_generate(@content)
end