Spring/spring-data-mongodb
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

DATAMONGO-1082 - Improved documentation of alias usage in aggregation framework.

Browse Source 
Added missing JavaDoc and added short note to the reference documentation.

Original pull request: #268.
This commit is contained in:
Thomas Darimont
2015-01-20 18:12:18 +01:00
committed by Oliver Gierke
parent 4055365c57
commit 3f7b0f1eb6
2 changed files with 26 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/Fields.java
View File

@@ -1,5 +1,5 @@
/*
* Copyright 2013-2014 the original author or authors.
* Copyright 2013-2015 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.
@@ -84,6 +84,15 @@ public final class Fields implements Iterable<Field> {
return new AggregationField(name);
}
/**
* Creates a {@link Field} with the given {@code name} and {@code target}.
* <p>
* The {@code target} is the name of the backing document field that will be aliased with {@code name}.
*
* @param name
* @param target must not be {@literal null} or empty
* @return
*/
public static Field field(String name, String target) {
Assert.hasText(target, "Target must not be null or empty!");
return new AggregationField(name, target);
@@ -187,15 +196,24 @@ public final class Fields implements Iterable<Field> {
private final String target;
/**
* Creates an aggregation field with the given name. As no target is set explicitly, the name will be used as target
* as well.
* Creates an aggregation field with the given {@code name}.
*
* @param key
* @see AggregationField#AggregationField(String, String).
* @param name must not be {@literal null} or empty
*/
public AggregationField(String key) {
this(key, null);
public AggregationField(String name) {
this(name, null);
}
/**
* Creates an aggregation field with the given {@code name} and {@code target}.
* <p>
* The {@code name} serves as an alias for the actual backing document field denoted by {@code target}. If no target
* is set explicitly, the name will be used as target.
*
* @param name must not be {@literal null} or empty
* @param target
*/
public AggregationField(String name, String target) {
String nameToSet = cleanUp(name);

3
src/main/asciidoc/reference/mongodb.adoc
View File

@@ -1538,7 +1538,8 @@ Note that the aggregation operations not listed here are currently not supported
[[mongo.aggregation.projection]]
=== Projection Expressions
Projection expressions are used to define the fields that are the outcome of a particular aggregation step. Projection expressions can be defined via the `project` method of the `Aggregate` class.
Projection expressions are used to define the fields that are the outcome of a particular aggregation step. Projection expressions can be defined via the `project` method of the `Aggregate` class either by passing a list of `String`s or an aggregation framework `Fields` object. The projection can be extended with additional fields through a fluent API via the `and(String)` method and aliased via the `as(String)` method.
Note that one can also define fields with aliases via the static factory method `Fields.field` of the aggregation framework that can then be used to construct a new `Fields` instance.
.Projection expression examples
====