Sidub.Platform.Filter 1.1.3

Sidub Platform - Filter

This repository contains the filter module for the Sidub Platform. Filter concept abstractions allow definition of filters while language-specific parser implementations allow for the parsing of filter definitions.

Main Components

Filter Concepts

A filter is represented as an IFilter with FilterPredicate, FilterPipeline and FilterLogicalOperator as the main concrete concepts. The FilterPredicate is the basic building block of a filter and represents a single condition. The FilterPipeline is a collection of IFilter instances and the FilterLogicalOperator is used to combine IFilter instances within the a pipeline.

Filters may be built using the FilterBuilder class which provides a fluent API for building filters.

Filter Parsing

A filter representation can be parsed to its string representation using the appropriate parser. Various language-specific parsers exist to parse filters to appropriate string representations.

Usage

While filters can be manually composed using the respective IFilter implementations, the FilterBuilder class provides a fluent API for building filters. Once prepared, the filter can be parsed to its string representation using the appropriate parser service.

Building a Filter

To build a simple filter, you can use the FilterBuilder as follows:

var builder = new FilterBuilder();
var filter = builder
	.Add("FieldA", ComparisonOperator.Equals, "FieldATestValue")
	.Build();

For filters with multiple conditions, you can use the FilterPipeline and FilterLogicalOperator as follows:

var builder = new FilterBuilder();

var filter = builder
	.Add("FieldA", ComparisonOperator.Equals, "FieldATestValue")
	.Add(LogicalOperator.And)
	.Add("FieldB", ComparisonOperator.NotEquals, "FieldBTestValue");

Pipelines can be nested to create more advanced filters:

var builder = new FilterBuilder();

var filter = builder
	.Add("FieldA", ComparisonOperator.Equals, "FieldATestValue")
	.Add(LogicalOperator.And)
	.Add(inner1 => inner1
		.Add("FieldB", ComparisonOperator.Equals, "FieldBTestValue01")
		.Add(LogicalOperator.Or)
		.Add("FieldB", ComparisonOperator.Equals, "FieldBTestValue02"));

Parsing a Filter

To parse a filter to its string representation, you can use the appropriate parser service. Concrete implementations of the IFilterService<TConfiguration> interface are provided for various languages.

private readonly ODataFilterService _filterService;

public ProductService(ODataFilterService filterService)
{
	_filterService = filterService;
}

public string BuildProductQuery(ProductFilter productFilter)
{
	return _filterService.Parse(filterFilter);
}

Considerations

The library currently only supports implementations in which the filter is parsed to a string representation. Future implemenations will evolve this concept to support more advanced use-cases, such as applying the filter against an in-memory collection or against other query constructs.

License

This project is dual-licensed under the AGPL v3 or a proprietary license. For details, see https://sidub.ca/licensing or the LICENSE.txt file.