DataFilter.Core 1.1.0

DataFilter.Core

The foundation of the DataFilter library, providing pure filtering logic, abstractions, and standard data models.

Structure

• Abstractions: Defines IFilterEngine, IFilterDescriptor, IFilterContext, IAsyncDataProvider, etc.
• Engine: Includes FilterExpressionBuilder for standard LINQ filter generation.
• Models: Standardized FilterSnapshot, FilterPipelineSnapshot, SortDescriptor, and PagedResult.
• Pipeline (Pipeline/): FilterPipeline, CriterionPipelineNode, GroupPipelineNode — editable graph for UI scenarios (order, named groups, toggles).
• Services: FilterSnapshotBuilder, FilterPipelineCompiler, FilterPipelineSnapshotMapper, FilterPipelineInterop, FilterPipelineContextExtensions.

Key Concepts

Wildcards in text operators (*, ?)

Core text operators (Equals, NotEquals, Contains, NotContains, StartsWith, EndsWith) support wildcard patterns:

• * matches any sequence of characters
• ? matches a single character

This behavior is implemented in FilterEvaluator and FilterExpressionBuilder, so it applies consistently to in-memory filtering and compiled expressions. It also means persisted presets/snapshots that store a text operator + pattern will replay correctly without needing UI-specific logic.

FilterSnapshot

A serializable representation of a filtering state that can be passed between layers (e.g., from Blazor UI to Web API). Describes what is filtered using flat or nested FilterSnapshotEntry rows (including logical groups for Excel-style column scopes).

Filter pipeline

For applications that need an ordered list of criteria, named groups, enable/disable flags, and JSON presets, use the pipeline model:

Apply to runtime state with FilterContext.ReplaceDescriptors(FilterPipelineCompiler.Compile(pipeline)) or FilterPipelineContextExtensions.ApplyToContext(pipeline, filterContext). This replaces the entire descriptor list; it does not merge by property name (unlike AddOrUpdateDescriptor).

IAsyncDataProvider

Implement this interface to provide data asynchronously from any source (SQL, NoSQL, API).

public interface IAsyncDataProvider<T>
{
    Task<PagedResult<T>> FetchDataAsync(IFilterContext context, CancellationToken cancellationToken = default);
    Task<IEnumerable<object>> FetchDistinctValuesAsync(string propertyName, string searchText = "", CancellationToken cancellationToken = default);
}