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012// ***************************************************************************************************************************
013package org.apache.juneau.rest.converters;
014
015import org.apache.juneau.rest.*;
016import org.apache.juneau.utils.*;
017
018/**
019 * Converter for enabling of {@link PojoQuery} support on response objects returned by a <code>@RestMethod</code> method.
020 * 
021 * <p>
022 * When enabled, objects in a POJO tree can be filtered using the functionality described in the {@link PojoQuery}
023 * class.
024 * 
025 * <p>
026 * The following HTTP request parameters are available for tabular data (e.g. {@code Collections} of {@code Maps},
027 * arrays of beans, etc...):
028 * <ul class='spaced-list'>
029 *    <li>
030 *       <code>&amp;s=</code> Search arguments.
031 *       <br>Comma-delimited list of key/value pairs representing column names and search tokens.
032 *       <br>Example:
033 *       <p class='bcode'>
034 *    &amp;s=name=Bill*,birthDate&gt;2000
035 *       </p>
036 *    <li>
037 *       <code>&amp;v=</code> Visible columns.
038 *       <br>Comma-delimited list of column names to display.
039 *       <br>Example:
040 *       <p class='bcode'>
041 *    &amp;v=name,birthDate
042 *       </p>
043 *    <li>
044 *       <code>&amp;o=</code> Sort commands.
045 *       <br>Comma-delimited list of columns to sort by.
046 *       <br>Column names can be suffixed with <js>'+'</js> or <js>'-'</js> to indicate ascending or descending order.
047 *       <br>The default is ascending order.
048 *       <br>Example: 
049 *       <p class='bcode'>
050 *    &amp;o=name,birthDate-
051 *       </p>
052 *    <li>
053 *       <code>&amp;i=</code> Case-insensitive parameter.
054 *       <br>Boolean flag for case-insensitive matching on the search parameters.
055 *    <li>
056 *       <code>&amp;p=</code> - Position parameter.
057 *       <br>Only return rows starting at the specified index position (zero-indexed).
058 *       <br>Default is {@code 0}.
059 *    <li>
060 *       <code>&amp;l=</code> Limit parameter.
061 *       <br>Only return the specified number of rows.
062 *       <br>Default is {@code 0} (meaning return all rows).
063 * </ul>
064 * 
065 * <h5 class='section'>See Also:</h5>
066 * <ul>
067 *    <li class='jc'>{@link PojoQuery} - Additional information on filtering POJO models.
068 *    <li class='jf'>{@link RestContext#REST_converters} - Registering converters with REST resources.
069 *    <li class='link'><a class="doclink" href="../../../../../overview-summary.html#juneau-rest-server.Converters">Overview &gt; juneau-rest-server &gt; Converters</a>
070 * </ul>
071 */
072public final class Queryable implements RestConverter {
073
074   @Override /* RestConverter */
075   public Object convert(RestRequest req, Object o) {
076      if (o == null)
077         return null;
078      SearchArgs searchArgs = req.getQuery().getSearchArgs();
079      if (searchArgs == null)
080         return o;
081      return new PojoQuery(o, req.getBeanSession()).filter(searchArgs);
082   }
083}