ValidationEnforcer.java

// Copyright 2016 Google, Inc.
//
// 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 com.firebase.jobdispatcher;

import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.text.TextUtils;
import java.util.List;

/**
 * Wraps a JobValidator and provides helpful validation utilities.
 */
public class ValidationEnforcer implements JobValidator {
    private final JobValidator mValidator;

    public ValidationEnforcer(JobValidator validator) {
        mValidator = validator;
    }

    /**
     * {@inheritDoc}
     */
    @Nullable
    @Override
    public List<String> validate(JobParameters job) {
        return mValidator.validate(job);
    }

    /**
     * {@inheritDoc}
     * @param trigger
     */
    @Nullable
    @Override
    public List<String> validate(JobTrigger trigger) {
        return mValidator.validate(trigger);
    }

    /**
     * {@inheritDoc}
     */
    @Nullable
    @Override
    public List<String> validate(RetryStrategy retryStrategy) {
        return mValidator.validate(retryStrategy);
    }

    /**
     * Indicates whether the provided JobParameters is valid.
     */
    public final boolean isValid(JobParameters job) {
        return validate(job) == null;
    }

    /**
     * Indicates whether the provided JobTrigger is valid.
     */
    public final boolean isValid(JobTrigger trigger) {
        return validate(trigger) == null;
    }

    /**
     * Indicates whether the provided RetryStrategy is valid.
     */
    public final boolean isValid(RetryStrategy retryStrategy) {
        return validate(retryStrategy) == null;
    }

    /**
     * Throws a RuntimeException if the provided JobParameters is invalid.
     *
     * @throws ValidationException
     */
    public final void ensureValid(JobParameters job) {
        ensureNoErrors(validate(job));
    }

    /**
     * Throws a RuntimeException if the provided JobTrigger is invalid.
     *
     * @throws ValidationException
     */
    public final void ensureValid(JobTrigger trigger) {
        ensureNoErrors(validate(trigger));
    }

    /**
     * Throws a RuntimeException if the provided RetryStrategy is
     * invalid.
     *
     * @throws ValidationException
     */
    public final void ensureValid(RetryStrategy retryStrategy) {
        ensureNoErrors(validate(retryStrategy));
    }

    private void ensureNoErrors(List<String> errors) {
        if (errors != null) {
            throw new ValidationException("JobParameters is invalid", errors);
        }
    }

    /**
     * An Exception thrown when a validation error is encountered.
     */
    public final static class ValidationException extends RuntimeException {
        private final List<String> mErrors;

        public ValidationException(String msg, @NonNull List<String> errors) {
            super(msg + ": " + TextUtils.join("\n  - ", errors));
            mErrors = errors;
        }

        public List<String> getErrors() {
            return mErrors;
        }
    }
}