Android Open Source - spades Related Child

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License

The source code is released under:

Apache License

Java Source Code

/**
 * Copyright (C) 2013 Pau Picas Sans <pau.picas@gmail.com>
 */*www  .  j av a2 s  .  c o m*/
 * 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 cat.picas.spades;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import cat.picas.spades.query.Query;

public class RelatedChild<T extends Entity> {

  private Entity mParent;
  private Column mChildColumn;
  private Table mChildTable;
  private EntityMapper<T> mChildMapper;
  private String mExtraWhere;

  private boolean mFetched;
  private T mChild;

  public RelatedChild(Entity parent, Column childColumn, EntityMapper<T> childMapper) {
    mParent = parent;
    mChildColumn = childColumn;
    mChildTable = mChildColumn.getTable();
    mChildMapper = childMapper;
  }

  public RelatedChild(Entity parent, Column childColumn, EntityMapper<T> childMapper,
      String extraWhere) {
    this(parent, childColumn, childMapper);
    mExtraWhere = extraWhere;
  }

  public boolean isFetched() {
    return mFetched;
  }

  public void reset() {
    mChild = null;
    mFetched = false;
  }

  public T fetch(SQLiteDatabase db) {
    if (!mFetched && mParent.getEntityId() != null) {
      Query query = createFetchQuery();
      Cursor cursor = query.execute(db);
      if (cursor.moveToFirst()) {
        mChild = mChildMapper.createFromCursor(cursor, query.getCursorInfo());
      } else {
        mChild = null;
      }
      cursor.close();
      mFetched = true;
    }

    return mChild;
  }

  public T fetch(Cursor cursor, CursorInfo cursorInfo) {
    if (!mFetched) {
      // Check if the cursor contains data for this entity.
      if (!cursorInfo.hasTable(mChildTable)) {
        return null;
      }

      // If we have enough information check if the child entity ID is
      // equal to the parent ID, if they are different then we discard
      // this child.
      int childColIndex = cursorInfo.getColumnIndex(mChildColumn);
      if (childColIndex != CursorInfo.INVALID_INDEX
          && !cursor.isNull(childColIndex) && mParent.getEntityId() != null
          && !mParent.getEntityId().equals(cursor.getLong(childColIndex))) {
        return null;
      }

      mChild = mChildMapper.createFromCursor(cursor, cursorInfo);
      mFetched = true;
    }

    return mChild;
  }

  public T get() {
    return mChild;
  }

  public void set(T entity) {
    mChild = entity;
    mFetched = true;
  }

  protected Query createFetchQuery() {
    Query query = new Query(mChildTable).where(mChildColumn, "=" + mParent.getEntityId()).limit(1);
    if (mExtraWhere != null) {
      query.where(mExtraWhere);
    }

    return query;
  }

}

Java Source Code List

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