de.vandermeer.skb.interfaces.antlr.IsST Maven / Gradle / Ivy

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Set of interfaces used by other SKB projects.
There is a newer version: 0.0.2
/* Copyright 2016 Sven van der Meer 
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package de.vandermeer.skb.interfaces.antlr;

import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;

import org.apache.commons.lang3.Validate;
import org.stringtemplate.v4.ST;

import de.vandermeer.skb.interfaces.categories.CategoryIs;
import de.vandermeer.skb.interfaces.render.DoesRender;

/**
 * Interface for objects that represent String Template (ST) objects
 * (for which one can check chunks etc).
 *
 * @author     Sven van der Meer <[email protected]>
 * @version    v0.0.1 build 170404 (04-Apr-17) for Java 1.8
 * @since      v0.0.1
 */
public interface IsST extends DoesRender, CategoryIs {

	/**
	 * Returns the ST object.
	 * @return ST object
	 */
	ST getST();

	@Override
	default String render() {
		if(this.getST()==null){
			return "";
		}
		return this.getST().render();
	};

	/**
	 * Returns the arguments expected to be defined in the ST object.
	 * @return expected arguments as set of argument names
	 */
	Set getExpectedArguments();

	/**
	 * Validates the ST for expected arguments.
	 * @return a set of error messages, empty if no errors found, null if no expected arguments where set or no ST was set
	 */
	default Set validate(){
		if(this.getExpectedArguments()==null){
			return null;
		}
		if(this.getST()==null){
			return null;
		}

		Set ret = new LinkedHashSet<>();
		Map formalArgs = this.getST().impl.formalArguments;
		if(formalArgs==null){
			for(String s : this.getExpectedArguments()){
				ret.add("ST <" + this.getST().getName() + "> does not define expected argument <" + s + ">");
			}
		}
		else{
			for(String s : this.getExpectedArguments()){
				if(!formalArgs.containsKey(s)){
					ret.add("ST <" + this.getST().getName() + "> does not define expected argument <" + s + ">");
				}
			}
		}
		return ret;
	}

	/**
	 * Creates a new IsST object.
	 * @param st the contained ST object
	 * @return new IsST object
	 * @throws NullPointerException if `st` was null
	 */
	static IsST create(ST st){
		return IsST.create(st, null);
	}

	/**
	 * Creates a new IsST object.
	 * @param st the contained ST object
	 * @param expectedArguments set of expected arguments for the ST
	 * @return new IsST object
	 * @throws NullPointerException if `st` was null or the expected arguments was not null and contained null elements
	 */
	static IsST create(final ST st, final Set expectedArguments){
		Validate.notNull(st);
		if(expectedArguments!=null){
			Validate.noNullElements(expectedArguments);
		}

		return new IsST() {
			@Override
			public ST getST() {
				return st;
			}

			@Override
			public Set getExpectedArguments() {
				return expectedArguments;
			}
		};
	}
}