Add support for custom scalar types #33
Closed
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Move the GQLResponseParser into the gql library.
Each time a GQL query is made by the client, the response is passed through
ResponseParser.parse() where it is processed.
Configure your own custom scalars as follows:
```
custom_scalars = {
'SomeCustomScalar': <ScalarClass>
}
gql_client = GQLClient(transport=gql_transport,
schema=schema,
custom_scalars=custom_scalars)
gql_client.execute(...)
```
<ScalarClass> should have a .parse_value(value) function
There are a few anti-patterns I have had to include in order to support
some new functionality that we require:
- client.execute now accepts `url` and `headers` as arguments, since we
need to be able to set these on a per request basis. Previously they were
supplied by the transport (which gets set only once at initialization
time).
- As a consequence, the url supplied in to the transport goes unused if a
url is passed in to `execute()`. It is a required field so I have to pass
in a string, but it's not the best.
ahussain3
force-pushed
the
awais/waveussd-to-graphql
branch
from
a3e2181 to
a63ed8b
Compare
added 7 commits
May 1, 2018 12:52
The tests were copied over from a different repo and so were inconsistent with the Star Wars schema we are using here. This PR should fix the tests (although we are still using a remote schema rather than a local one, so the tests run slowly becuase they need to make a http request each time).
The 'ResponseParser' name was confusing because it was too broad, and we weren't really actually parsing the response. Hopefully this makes it clearer that what we are actually doing it just adding support for custom types.
Stick to the format of having a one line summary followed by more detailed information.
Since we are now merging the headers specified in the transport with the headers specified on a per request basis, we need to make sure the old headers are of type `dict`, a `None` is not sufficient.
GQLServerError maps to errors which are generated on the backend server. I.e. the server responds with a <200 OK> but an "errors" field is included within the response. These are often user facing errors and should be handled as such. GQLSyntaxError maps to cases where either the query or the schema is improperly formatted. This usually indicates a mistake in the code.
Previously we were using Python3.5+ type annotation syntax but this is not backwards compatible so we are removing it.
ahussain3
force-pushed
the
awais/waveussd-to-graphql
branch
from
a63ed8b to
2988ed5
Compare
|
It's a bit sad that gql has been dormant and PRs like this did not receive feedback. I will try to get this merged into v3 (modern version), and if requested backport from there to v2 (legacy version). Also, I will probably make this a bit more general to support all kinds of leaf types, i.e. also Enum types. |
Closed
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
In the GraphQL schema, it is possible to specify (CustomScalarTypes)[https://www.apollographql.com/docs/graphql-tools/scalars.html].
In order to specify a Custom Scalar Type, you need to define an object which implements the following interface:
serialize()parse_literal()parse_value()These methods allow GraphQL to translate between the serialized and deserialized versions of the custom scalar object.
However, when the GQL schema is passed around it includes only the names of the custom scalar types, and not the serialization/deserialization methods. After this PR is merged, you should be able to define your own classes on the client, and by giving them a
parse_value()method you can use them as custom scalar types.To configure the gql client to use your custom scalar types, you should do: