From 38aa6b3f71a53a11cde8e8360ca4b72c009191cc Mon Sep 17 00:00:00 2001 From: Thiago Santos Date: Wed, 30 Jun 2021 01:38:09 -0300 Subject: [PATCH] Update README.md --- README.md | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/README.md b/README.md index 7028a4c..9cbfd11 100644 --- a/README.md +++ b/README.md @@ -8,8 +8,7 @@ [![Maven Central](https://maven-badges.herokuapp.com/maven-central/io.github.thiagolvlsantos/json-predicate/badge.svg)](https://repo1.maven.org/maven2/io/github/thiagolvlsantos/json-predicate/) [![Hex.pm](https://img.shields.io/hexpm/l/plug.svg)](http://www.apache.org/licenses/LICENSE-2.0) - -Predicate builder over a JSON specification. Specify you query in a JSON format and check it against a given object. +Specify a predicate in a JSON format and check it against a given object. ## Usage @@ -25,9 +24,9 @@ Include latest version [![Maven Central](https://maven-badges.herokuapp.com/mave ## Predicates -The objective of this API is to create a `Predicate` based on a JSON specification of attributes and logical operations. +The objective of this library is to create a `Predicate` based on a JSON specification which includes different types of predicates. The general idea is that these JSON predicates can be build using a GUI and be used in `filter` operations. -An example of a JSON predicate: +An example of a JSON predicate filtering objects (or maps) whose field/key called 'name' contains the String 'project': ```json { "name": { @@ -36,19 +35,21 @@ An example of a JSON predicate: } ``` -Suppose there is a `List` where each project has a name, the following code will filter only those with `project` in its attribute name. +Suppose there is a `List` where each project has a `String:name` attribute, the following code will filter only those with `project` in its attribute 'name'. ```java + String filter = "{\"name\":{\"$contains\": \"project\"}}"; IPredicateFactory factory = new PredicateFactoryJson(); - Predicate p = factory.read("{\"name\":{\"$contains\": \"project\"}}"); - List projects = ...//load list + Predicate p = factory.read(filter); + List projects = ...// loaded list from somewhere return projects.stream().filter(p).collect(Collectors.toList()); ``` +In this example, if we provide the filter value using a GUI the underlying Java code remains unchanged. ## Predefined constructors -The set of build-in operators provided. +Bellow a list of the built-in provided predicates, you can register you own predicate. Checkout the interface [`IPredicateManager`](https://github.com/thiagolvlsantos/json-predicate/blob/master/src/main/java/io/github/thiagolvlsantos/json/predicate/impl/PredicateManagerDefault.java) implementation. ### Logical operators @@ -74,7 +75,7 @@ The set of build-in operators provided. |$contains or $c | ``` {"name": {"$contains": "proj"} }```| |$ncontains or $nc | ``` {"name": {"$ncontains": "A"} }```| |$match or $m | ``` {"name": {"$match": "\d{8}"} }```| -|$nmatch or $nm | ``` {"name": {"$nm": "\d{8}"} }```| +|$nmatch or $nm | ``` {"name": {"$nmatch": "\d{8}"} }```| ## Build