co.jirm.orm.builder.ConditionVisitors.java Source code

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Here is the source code for co.jirm.orm.builder.ConditionVisitors.java

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/**
 * Copyright (C) 2012 the original author or authors.
 *
 * 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 co.jirm.orm.builder;

import co.jirm.core.sql.Parameters;
import co.jirm.core.util.SafeAppendable;

import com.google.common.collect.ImmutableList;

public class ConditionVisitors {
    public static ConditionVisitor conditionVisitor(final Appendable appendable) {

        final SafeAppendable sb = new SafeAppendable(appendable);

        ConditionVisitor v = new ConditionVisitor() {
            private int depth = 0;

            @Override
            public void visitAnd(ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
                depth++;
                doCondition(" AND ", conditions, parameters);

            }

            @Override
            public void visitOr(ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
                depth++;
                doCondition(" OR ", conditions, parameters);
            }

            private void doCondition(String op, ImmutableList<ImmutableCondition> conditions,
                    Parameters parameters) {
                if (conditions.size() == 1) {
                    sb.append(op);
                    conditions.get(0).accept(this);

                } else {
                    boolean top = depth == 1;
                    if (!top)
                        sb.append("( ");
                    boolean first = true;
                    for (ImmutableCondition c : conditions) {
                        if (first) {
                            first = false;
                            c.accept(this);
                        } else {
                            sb.append(op);
                            c.accept(this);
                        }

                    }
                    if (!top)
                        sb.append(" )");
                }
            }

            @Override
            public void visitSql(String sql, Parameters parameters) {
                sb.append(sql);
            }
        };
        return v;
    }

    public static abstract class ParametersConditionVisitor extends ConditionVisitor {

        @Override
        public void visitAnd(ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
            super.visitAnd(conditions, parameters);
            doParameters(parameters);
        }

        @Override
        public void visitOr(ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
            super.visitOr(conditions, parameters);
            doParameters(parameters);
        }

        @Override
        public void visitSql(String sql, Parameters parameters) {
            doParameters(parameters);
        }

        public abstract void doParameters(Parameters p);

    }
}