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README.md

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 # DynamicExpressions
- A dynamic expression builder that can be used to dynamically sort and/or filter LINQ/EF queries
+
+A dynamic expression builder that can be used to dynamically sort and/or filter LINQ/EF queries.  
+I wrote a blog post that explains the usage & benefits, check it out [here](https://blog.zhaytam.com/2020/05/17/dynamic-sorting-filtering-csharp/).
+
+This library tries to generate Expression Trees as close to the one generated by c# as possible, so in almost all cases, you don't even need to worry about performance.
+
+||Badges|
+|--|--|
+|NuGet|[![NuGet](https://img.shields.io/nuget/v/DynamicExpressions.NET.svg)](https://www.nuget.org/packages/DynamicExpressions.NET) [![Nuget](https://img.shields.io/nuget/dt/DynamicExpressions.NET.svg)](https://www.nuget.org/packages/DynamicExpressions.NET)|
+|License|[![GitHub](https://img.shields.io/github/license/zHaytam/DynamicExpressions.svg)](https://github.com/zHaytam/DynamicExpressions)|
+
+## Property Getters
+
+This is usually used when you want to do an `OrderBy` or `OrderByDescending`.  
+For example:
+
+```cs
+_dbContext.Products.AsQueryable().OrderBy(p => p.Price);
+```
+
+If you want to give the ability for the user to choose what to order by, you'll need to do a switch statement with all the possible values, which can be exhausting, especially if it's for multiple entities.
+
+Using this library, you can simply do this:
+
+```cs
+var propertyGetter = DynamicExpressions.GetPropertyGetter<Product>(propertySentByUser);
+// ^ can be cached or even compiled to a Func<Product, object>
+var query = _dbContext.Products.AsQueryable().OrderBy(propertyGetter);
+// Or OrderByDesceding
+```
+
+And it will handle all the properties, unless you do a pre-validation.
+
+## Predicates
+
+### Simple
+
+Predicates in c# are functions that take one or more parameter and returns a boolean.  
+For example, when you want to filter an `IQueryable`, you use a `Func<TEntity, bool>`.
+
+For example:
+```cs
+_dbContext.Products.AsQueryable().Where(p => p.Name.Contains(termSentByUser));
+```
+
+Again, this only handles a `Contains` filter on the `Name` property.  
+The more properties and operators you have, the more "boring" code you'll need to write.
+
+Using this library, you can simple do this:
+
+```cs
+var predicate = DynamicExpressions.GetPredicate<Product>(propertySentByUser, operatorSentByUser, valueSentByUser);
+// ^ can also be cached or compiled and used anywhere
+var products = _dbContext.Products.AsQueryable().Where(predicate).ToList();
+// ^ or FirstByDefault, Any, etc...
+```
+
+### Advanced
+
+In the previous example, we filtered products only on their price. We will now see how we can create advnaced dynamic predicates.
+
+Let's say for example you want to create the following filter:
+
+```cs
+Product.Enabled
+&& (Product.Brand == "Nike" || Product.Brand == "Adidas")
+&& (Product.Price >= 20 && Product.Price <= 100)
+```
+
+Using this library, you're able to do this:
+
+```cs
+var predicate = new DynamicFilterBuilder<Product>()
+  .And("Enabled", FilterOperator.Equals, true)
+  .And(b => b.And("Brand", FilterOperator.Equals, "Nike").Or("Brand", FilterOperator.Equals, "Adidas"))
+  .And(b => b.And("Price", FilterOperator.GreaterThanOrEqual, 20).And("Price", FilterOperator.LessThanOrEqual, 100))
+  .Build();
+
+var products = _dbContext.Products.AsQueryable().Where(predicate).ToList();
+```
+
+Of course, everything can be configurable and provided by the user.  
+A more real life example would be for the frontend (user) to give you a list of filters that you can dynamically apply using a `DynamicFilterBuilder`.
+
+## Feedback
+
+If you find a bug or you want to see a functionality in this library, feel free to open an issue in the repository!  
+Of course, PRs are very welcome.