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Recall from App
(RapidMiner Studio Core)
Synopsis
This operator retrieves the specified object from a RapidMiner Server App or the current RapidMiner Studio session. Ojects can be stored by using the Publish to App operator.Description
The Recall from App operator can be used for retrieving the specified object from a RapidMiner Server App or the current RapidMiner Studio session. The name of the object is specified through the name parameter. The Recall from App operator is always used in combination with the Publish to App operator. For the Recall from App operator to retrieve an object, first it is necessary that the object has to be stored by using the Publish to App operator. The name of the object is specified when the object is stored. The same name (in name parameter) should be specified in the Recall from App operator to retrieve that object. The same object can be retrieved multiple times, even from within another process, if the remove from app parameter of the Recall from App operator is not set to true. When an object was stored by the Publish to App operator once, it can be recalled at any point in the RapidMiner Server App or the current RapidMiner Studio session. But care should be taken that the execution order of operators is such that the Publish to App operator for an object always executes before the Recall from App operator for that object. The combination of these two operators can be used to build complex RapidMiner Server Apps where an input object is stored once and used in completely different parts of the App later on.
Differentiation
Publish to App
The Recall from App operator is always used in combination with the Publish to App operator. The Publish to App operator stores the input object in the RapidMiner Server App and the Recall from App operator retrieves the stored object when required.
Input
through (Data Table)It is not compulsory to connect any object with this port. Any object connected at this port is delivered without any modifications to the output port. This operator can have multiple inputs. When one input is connected, another through input port becomes available which is ready to accept another input (if any). The order of inputs remains the same. The object supplied at the first through input port of the Recall from App operator is available at the first through output port.
Output
resultThe specified object is retrieved from the RapidMiner Server App or the current RapidMiner Studio session and is delivered through this output port.
- through (Data Table)
The objects that were given as input are passed without changing to the output through this port. It is not compulsory to attach this port to any other port, the specified object is retrieved from the RapidMiner Server App even if this port is left without connections. The Recall from App operator can have multiple outputs. When one output is connected, another through output port becomes available which is ready to deliver another output (if any). The order of outputs remains the same. The object delivered at the first through input port of the Recall from App operator is delivered at the first through output port
Parameters
- nameThe name of the required object is specified through this parameter. This name should be the same name that was used while storing the object in an earlier call of the operator Publish to App. Range: string
- remove_from_dashboardIf this parameter is set to true, the specified object is removed from the RapidMiner Server App or the current RapidMiner Studio session after it has been retrieved. In such a case the object can be retrieved just once. If this parameter is set to false, the object remains in the RapidMiner Server App even after retrieval. Thus the object can be retrieved by multiple Recall from App operators. Range: boolean
Tutorial Processes
Introduction to Publish to App and Recall from App operators
This process uses the combination of the Publish to App and Recall from App operators to display the testing data set of the Split Validation operator. The testing data set is present in the testing subprocess of the Split Validation operator but it is not available outside the Split Validation operator.
The 'Golf' data set is loaded using the Retrieve operator. The Split Validation operator is applied on it. The test set size parameter is set to 5 and the training set size parameter is set to -1. Thus the test set in the testing subprocess will be composed of 5 examples. The Default Model operator is used in the training subprocess to train a model. The testing data set is available at the tes port of the testing subprocess. The Publish to App operator is used to store the testing data set in the RapidMiner Server App. The name and io object parameters are set to 'Testset' and 'ExampleSet' respectively. The Apply Model and Performance operator are applied in the testing subprocess later. In the main process, the Recall from App operator is used to retrieve the testing data set. The name and io object parameters of the Recall from App operator are set to 'Testset' and 'ExampleSet' respectively to retrieve the object that was cached by the Publish to App operator. The output of the Recall from App operator is connected to the result port of the process. Therefore the testing data set can be seen in the Results view.
The operator Recall from App cannot be used to retrieve objects stored with the Remember operator, and the operator Recall cannot be used to retrieve objects stored with the Publish to App operator. They do not use the same storage.
The difference to the operators Remember and Recall is that Publish to App does not only store an object for the process execution (as the Remember operator does), but for the lifetime of a RapidMiner Server App. This means that the Recall from App operator could also be part of another process in the same RapidMiner Server App and would retrieve the same object as long as the process, which remembers the object for the App, was executed beforehand.
