Allow custom graphql params extraction from request

[TrySound]

In my app I'm trying to move away from express. I implemented own
body parser to not pollute request object. Though in this case
express-graphql is trying to parse body by itself which leads to hanging
server because there are no more events on request.

In this diff I added a way to custom extracting params from request.
It would look better in options though options getter depends on parsed
options.

[TrySound]

cc @IvanGoncharov

[acao]

excellent idea for decoupling from express.

after a quick review:

• should there be a change to package lock without dependency changes?
• potentially the function could be named more descriptively? also i think “custom” is a given in this case

[acao]

also i think it makes sense to append this to the options interface rather than introducing a second argument

[TrySound]

Hi @acao

also i think it makes sense to append this to the options interface rather than introducing a second argument

It would look better in options though options getter depends on parsed
options.

See here https://github.com/graphql/express-graphql/blob/master/src/index.ts#L231

should there be a change to package lock without dependency changes?

Probably not. I just committed what npm i gives. I usually use yarn which does not introduce any changes unless packages upgraded explicitly.

potentially the function could be named more descriptively? also i think “custom” is a given in this case

I don't know, maybe customGetGraphQLParams?

[acao]

@TrySound is there a reason you didn't want to add this to the Options interface?

[TrySound]

I cannot because of options getter which depends on params. If we could get rid of it Im good to move into options

It would look better in options though options getter depends on parsed
options.

[TrySound]

@acao I figured how to move it into options. Now builtin getGraphQLParams is called only for options getter. When only object is passed first look for customGraphQLParamsFn field.

[TrySound]

Hi @acao. What do you think?

[acao]

@TrySound you did move the option to where I was hoping, awesome!

[IvanGoncharov]

@TrySound You can parse body yourself and replace body inside Request

express-graphql/src/parseBody.ts

Lines 34 to 38 in 0fa7ace

	// If express has already parsed a body as a string, and the content-type
	// was application/graphql, parse the string body.
	if (typeof body === 'string' && typeInfo.type === 'application/graphql') {
	return { query: body };
	}

Also, I'm worried that it will affect our effort to standardize the HTTP protocol for GraphQL:
https://github.com/graphql/graphql-over-http
As a reference GraphQL over HTTP server, we provide the ability to use non-standard names like graphqlQuery.

In my app I'm trying to move away from express.

We also have a plan to do that so we can support Koa, AWS Lambdas, Deno frameworks, etc.
We currently blocked by TS migration of graphql-js but this is planned for the 1.0 release, see #675

[TrySound]

You can parse body yourself and replace body inside Request

Yes, I do request pollution now though it's not very clean.

Also, I'm worried that it will affect our effort to standardize the HTTP protocol for GraphQL:

My change allows to move everything to userland and use any non-standard names. Any framework could be integrated here as well.