For a utility I'm working on, the client would like
to be able
to generate graphic reports on the data that has been collected. I can already generate a couple canned graphs (using ZedGraph, which is a very nice library); however, the utility would be much more flexible if the graphs were more programmable or configurable by the end-user.
TLDR version
I want users
to be able
to use something like SQL
to safely extract and select data from a List of objects that I provide and can describe. What free tools or libraries will help me accomplish this?
Full version
I've given thought
to using IronPython, IronRuby, and LuaInterface, but frankly they're all a bit overpowered for what I want
to do. My classes are fairly simple, along the lines of:
class Person:
string Name;
int HeightInCm;
DateTime BirthDate;
Weight[] WeighIns;
class Weight:
int WeightInKg;
DateTime Date;
Person Owner;
(exact classes have been changed
to protect the innocent).
To come up with the data for the graph, the user will choose whether it's a bar graph, scatter plot, etc., and then
to actually obtain the data, I would like
to obtain some kind of List from the user simply entering something SQL-ish along the lines of
SELECT Name, AVG(WeighIns) FROM People
SELECT WeightInKg, Owner.HeightInCm FROM Weights
And as a bonus, it would be nice if you could actually do operations as well:
SELECT WeightInKg, (Date - Owner.BirthDate) AS Age FROM Weights
The DSL doesn't have
to be compliant SQL in any way; it doesn't even have
to resemble SQL, but I can't think of a more efficient descriptive language for the task.
I'm fine filling in blanks; I don't expect a library
to do everything for me. What I would expect
to exist (but haven't been able
to find in any way, shape, or form) is something like Fluent
NHibernate (which I am already using in the project) where I can declare a mapping, something like
var personRequest = Request<Person>();
personRequest.Item("Name", (p => p.Name));
personRequest.Item("HeightInCm", (p => p.HeightInCm));
personRequest.Item("HeightInInches", (p => p.HeightInCm * CM_TO_INCHES));
// ...
var weightRequest = Request<Weight>();
weightRequest.Item("Owner", (w => w.Owner), personRequest); // Indicate a chain
to personRequest
// ...
var people = Table<Person>("People", GetPeopleFromDatabase());
var weights = Table<Weight>("Weights", GetWeightsFromDatabase());
// ...
TryRunQuery(userInputQuery);
LINQ is so close
to what I want
to do, but AFAIK there's no way
to sandbox it. I don't want
to expose any unnecessary functionality
to the end user; meaning I don't want the user
to be able
to send in and process:
from p in people select (p => { System.IO.File.Delete("C:\\something\\important"); return p.Name })
So does anyone know of any free .NET libraries that allow something like what I've described above? Or is there some way
to sandbox LINQ? cs-script is close too, but it doesn't seem
to offer sandboxing yet either. I'd be hesitant
to expose the
NHibernate interface either, as the user should have a read-only view of the data at this point in the usage.
I'm using C# 3.5, and pure .NET solutions would be preferred.
The bottom line is that I'm really trying
to avoid writing my own parser for a subset of SQL that would only apply
to this single project.
