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/*
* Copyright (c) 2016 the original author or authors.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.rivescript.lang;
import com.rivescript.ObjectHandler;
import com.rivescript.ObjectMacro;
import com.rivescript.RiveScript;
import java.util.HashMap;
import static java.util.Objects.requireNonNull;
/**
* Java programming language support for RiveScript-Java.
*
* Note that since Java must be compiled before running, this object macro language is only
* available at compile-time using the {@link RiveScript#setSubroutine(String, ObjectMacro)} method.
* Inline Java code can't be parsed and compiled from RiveScript source files.
*
* @author Noah Petherbridge
* @see ObjectHandler
*/
public class Java implements ObjectHandler {
private RiveScript parent;
private HashMap handlers = new HashMap<>();
/**
* Constructs a Java {@link ObjectHandler}.
*
* @param rivescript The RiveScript instance, not null.
*/
public Java(RiveScript rivescript) {
this.parent = requireNonNull(rivescript, "'rivescript' must not be null");
}
/**
* Handler for when object code is read (loaded) by RiveScript. Should return {@code true} for
* success or {@code false} to indicate error.
*
* We can't dynamically evaluate Java code, so this function just logs an error.
*
* @param name The name of the object.
* @param code The source code inside the object.
*/
@Override
public boolean onLoad(String name, String[] code) {
System.err.println("NOTICE: Can't dynamically eval Java code from an "
+ "inline object macro! Use the setSubroutine() function instead "
+ "to define an object at compile time.");
return false;
}
/**
* Handler for when a user invokes the object. Should return the text reply from the object.
*
* @param name The name of the object being called.
* @param user The user's id.
* @param args The argument list from the tag.
*/
@Override
public String onCall(String name, String user, String[] args) {
// Does the object macro exist?
ObjectMacro macro = this.handlers.get(name);
if (macro == null) {
return "[ERR: Object Not Found]";
}
// Call it!
return macro.call(this.parent, args);
}
/**
* Sets a Java class to handle the {@link ObjectMacro} directly.
*
* This is called by the parent RiveScript object's
* {@link RiveScript#setSubroutine(String, ObjectMacro)} method.
*
* @param name The name of the object macro.
* @param impl The {@link ObjectMacro} implementation.
*/
@Override
public void setClass(String name, ObjectMacro impl) {
this.handlers.put(name, impl);
}
}