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Configurable Query Language
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README.md

Configurable Query Language (CQL)

Example

What is the problem?

The raison d'être for this project is the typical filter problem: On one side, your product delivers a dataset of complex types. On the other side the user wants to easily query certain rows in the dataset. But you also want to empower him to address complex properties.

Here is a solution!

The two components, provided here, are

  • a query language, that can be configured from a high-level point of view (like "my data has a field 'Name' of type 'String'") or/and from a low-level point of view (like "Use '+' to concat strings.")
  • a WPF user control (using the language) with auto-completion and tooltips for syntactical and semantical errors. The query can be typed in using the keyboard OR by clicking all ingredients together.

Quickstart

First, installation

PM> Install-Package CQL

Second, let me shortly explain the concepts. You actually need to provide three objects:

  • the query, which can be edited by the user
  • the context, which contains all variables, that are accessible for the query
  • the type system, which setups the way the variables can be queried or can be combined

Third, study the following code snippet:

[CQLType("Ticket", "Object of interest.")]
public class Ticket
{
	public Ticket(int id, string owner)
	{
		this.Id = id;
		this.Owner = owner;
	}

	[CQLNativeMemberProperty("Id", IdDelimiter.Dot)]
	public int Id { get; set; }

	[CQLNativeMemberProperty("Owner", IdDelimiter.Dot)]
	public string Owner { get; set; }
}
...
var typeSystemBuilder = new TypeSystemBuilder();
typeSystemBuilder.AddFromScan(typeof(Ticket));
var typeSystem = typeSystemBuilder.Build();

//DATA
var ticket1 = new Ticket() { Id = 123, Owner = "Me" };
var ticket2 = new Ticket() { Id = 124, Owner = "Myself" };
var ticket3 = new Ticket() { Id = 125, Owner = "I" };

//QUERY
var context = new EvaluationScope(typeSystem);
Assert.IsFalse(Queries.Evaluate("id > 123", ticket1, context));
Assert.IsFalse(Queries.Evaluate("id > 123 AND Owner = \"I\"", ticket2, context));
Assert.IsTrue(Queries.Evaluate("ID > 123 AND oWnEr = \"I\"", ticket3, context));

Current features

  • configurable type system
  • configurable context
  • configurable WPF component (in progress!!!)
    • beginner mode
    • expert mode
    • auto completion
    • syntax highlighting
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