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/*
*
* Copyright (c) 2013,2019 AT&T Knowledge Ventures
* SPDX-License-Identifier: MIT
*/
package com.att.research.xacmlatt.pdp.std.functions;
import java.util.List;
import com.att.research.xacml.api.DataType;
import com.att.research.xacml.api.Identifier;
import com.att.research.xacml.api.Status;
import com.att.research.xacml.std.StdStatus;
import com.att.research.xacml.std.StdStatusCode;
import com.att.research.xacmlatt.pdp.policy.FunctionArgument;
/**
* FunctionDefinitionHomogeneousSimple extends {@link com.att.research.xacmlatt.pdp.std.functions.FunctionDefinitionBase}
* with utility methods for ensuring the types of the arguments passed in the evaluate method matches the parameterized
* type, and the number of arguments is correct.
* When evaluated the resulting arguments must be simple data types, not bags.
*
* The various functions have the following needs with respect to their arguments:
*
* -
* The argument list size is pre-defined and all arguments can be evaluated at once before the function is called.
*
-
* The argument list size is pre-defined but the arguments must be evaluated one at a time by the function.
*
-
* The argument list size is not pre-defined.
*
* To support those needs this class includes methods for checking the list size and evaluating a single argument as well as
* combining those operations in a single method to make it simpler for the calling function.
*
* @author car
* @version $Revision: 1.3 $
*
* @param the java class for the value of the Output return result from the FunctionDefinition
* @param the java class for the value of the Input {@link com.att.research.xacmlatt.pdp.policy.FunctionArgument}s in the evaluate method
*/
public abstract class FunctionDefinitionHomogeneousSimple extends FunctionDefinitionBase {
// null means that number of arguments is variable
private Integer numArgs;
/**
* Constructor
*
* @param idIn Identifier
* @param dataTypeReturnIn DataType return
* @param dataTypeArgsIn DataType arguments
* @param nArgs number of arguments in the function
*/
public FunctionDefinitionHomogeneousSimple(Identifier idIn, DataType dataTypeReturnIn, DataType dataTypeArgsIn, Integer nArgs) {
super(idIn, dataTypeReturnIn, dataTypeArgsIn, false);
this.numArgs = nArgs;
}
/**
* Gets the number of arguments expected to this FunctionDefinition.
* For functions without a pre-defined number of arguments this is not used.
*
* @return the number of arguments expected to this FunctionDefinition.
*/
public Integer getNumArgs() {
return this.numArgs;
}
/**
* Validates the given List of FunctionArguments has the correct count and DataType and evaluates expressions.
* This combines both the argument list length check and the evaluation of all arguments on that list.
*
* @param listFunctionArguments the List of FunctionArguments to validate
* @param convertedValues List of converted values
* @return a {@link com.att.research.xacml.api.Status} indication with an error if the arguments are not valid
*/
public Status validateArguments(List listFunctionArguments, List convertedValues) {
/*
* See if we have to validate the number of arguments
*/
Status listLengthStatus = validateArgumentListLength(listFunctionArguments);
if ( ! listLengthStatus.isOk()) {
return listLengthStatus;
}
/*
* Now validate the types of the arguments
*/
for (int i = 0; i < listFunctionArguments.size(); i++) {
FunctionArgument functionArgument = listFunctionArguments.get(i);
ConvertedArgument argument = new ConvertedArgument<>(functionArgument, getDataTypeArgs(), false);
if ( ! argument.isOk()) {
// when a Status is returned that indicates an error, tell caller which arg had problem
return new StdStatus(argument.getStatus().getStatusCode(), argument.getStatus().getStatusMessage() + " at arg index " + i );
}
if (convertedValues != null) {
convertedValues.add(argument.getValue());
}
}
/*
* Everything passed the data type test, so we are good to go
*/
return StdStatus.STATUS_OK;
}
/**
* Validates the given List of FunctionArguments has the correct count.
*
* @param listFunctionArguments the List of FunctionArguments to validate
* @return a {@link com.att.research.xacml.api.Status} indication with an error if the arguments are not valid
*/
public Status validateArgumentListLength(List listFunctionArguments) {
/*
* See if we have to validate the number of arguments
*/
if ((listFunctionArguments == null && this.numArgs > 0 ) ||
(listFunctionArguments != null && this.numArgs != listFunctionArguments.size()) ) {
return new StdStatus(StdStatusCode.STATUS_CODE_PROCESSING_ERROR, "Expected " + this.numArgs + " arguments, got " +
((listFunctionArguments == null) ? 0 : listFunctionArguments.size()) );
}
/*
* Everything passed the data type test, so we are good to go
*/
return StdStatus.STATUS_OK;
}
}