Linq 2 OData

A simplistic script to replace your TypeScript written linq with odata filter.

How

0. Put in your package.json : "linq2odata": "conduce-group/linq2odata"
1. Import ODataProvider to your class
   • [Implementing the GetFromQuery(query :string) method (this should do the request to your OData Endpoint, adding query to the end of your request)]
2. You're ready to use most of the functionality!

For use of Where and Predicates

As part of your build process run:
./node_modules/.bin/linq2odata -o <ODataProvider/Extendees/Directory> -s <Directory/Using/ODataProviders>
-h for help

Features

• filter(filterQuery: string)
• top(topQuery: number)
• skip(skipQuery: number)
• count()
• orderby(field: string)
• Where(predicate: {(T) => boolean})
  • ==
  • !=
  • >
  • >=
  • <
  • <=

Why

Easier to type Linq than lookup filter protocol, no?

But why as a macro for Where

Two reasons:

1. Linq requires compilation/transpilation, starting a compiler/esprima at runtime ain't great on the ol' CPU
2. As you need some dynamic scoping to access those variables that you can get to in the linq via closure, if it wasn't done compile time you'd need some runtime eval like so:

let titleIWant : string = "someTitle";
let newFnc = new Function(Linq2OData.Where<SomeModel>(x => x.Title == titleIWant));
var g_ = eval("(" + String(newFnc) + ")");
g_();

How is it done

It looks over the -o folder recursively finding all those who extend ODataProvider, or who extend and extendee or who extendee an extendee of an extendee etc.. Then it'll search over -s folder recursively looking for those who import an extendee and use .Where on any variable. These will be replaced by .filter() statements.

Assumptions

1. Constants:
   • Import ODataProvider from 'linq2odata/dist/ODataProvider' [see Constants.ts to change]
   • Use require to import into a variable that is used [used in FileParser::getNameAndLineODPImport]
   • Default file ending of .js [see Constants.ts to change]
2. That relative file imports are done starting with "./" or "../"
3. That any use of .Where in a file that has imported an OData Provider (or extension of) should be replaced by filter

Todo

• Use angular dependancy injection to guarantee correct object
• better checking of lines
  • iterate over all declarations instead of assuming it's in first one of line
  • ensure that a class has class-y things in it
• null checking TS