Package Exports
- graphql-anywhere
- graphql-anywhere/lib/async
- graphql-anywhere/lib/async.js
- graphql-anywhere/lib/bundle.cjs.js
- graphql-anywhere/lib/bundle.esm.js
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (graphql-anywhere) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
graphql-anywhere
⚠️ This package is no longer used by Apollo Client as of version 3.0, has been deprecated, and will no longer be maintained. ⚠️
Run a GraphQL query anywhere, without a GraphQL server or a schema. Just pass in one resolver. Use it together with graphql-tag.
npm install graphql-anywhere graphql-tag
I think there are a lot of potentially exciting use cases for a completely standalone and schema-less GraphQL execution engine. We use it in Apollo Client to read data from a Redux store with GraphQL.
Let's come up with some more ideas - below are some use cases to get you started!
API
import graphql from 'graphql-anywhere'
graphql(resolver, document, rootValue?, context?, variables?, options?)
resolver
: A single resolver, called for every field on the query.- Signature is:
(fieldName, rootValue, args, context, info) => any
- Signature is:
document
: A GraphQL document, as generated by the template literal fromgraphql-tag
rootValue
: The root value passed to the resolver when executing the root fieldscontext
: A context object passed to the resolver for every fieldvariables
: A dictionary of variables for the queryoptions
: Options for execution
Options
The last argument to the graphql
function is a set of graphql-anywhere
-specific options.
resultMapper
: Transform field results after execution.- Signature is:
(resultFields, resultRoot) => any
- Signature is:
fragmentMatcher
: Decide whether to execute a fragment. Default is to always execute all fragments.- Signature is:
(rootValue, typeCondition, context) => boolean
- Signature is:
Resolver info
info
, the 5th argument to the resolver, is an object with supplementary information about execution. Send a PR or open an issue if you need additional information here.
isLeaf
: A boolean that istrue
if this resolver is for a leaf field of the query, i.e. one that doesn't have a sub-selection.resultKey
: The key the result of this field will be put under. It's either the field name from the query, or the field alias.directives
: An object with information about all directives on this field. It's an object of the format{ [directiveName]: { [argumentName]: value }}
. So for example a field with@myDirective(hello: "world")
will be passed as{ myDirective: { hello: 'world' }}
. Note that fields can't have multiple directives with the same name, as written in the GraphQL spec.
Utilities
See https://www.apollographql.com/docs/react/advanced/fragments.html for examples of how you might use these.
import { filter } from 'graphql-anywhere'
filter(doc, data);
doc
: a GraphQL document, as generated by the template literal fromgraphql-tag
, typically either a query or a fragment.data
: an object of data to be filtered by thedoc
Filter data
according to doc
.
import { check } from 'graphql-anywhere'
check(doc, data);
doc
: a GraphQL document, as generated by the template literal fromgraphql-tag
, typically either a query or a fragment.data
: an object of data, as may have been filtered bydoc
.
Check that data
is of the form defined by the query or fragment. Throw an exception if not.
import { propType } from 'graphql-anywhere'
X.propTypes = {
foo: propType(doc),
bar: propType(doc).isRequired,
}
doc
: a GraphQL document, as generated by the template literal fromgraphql-tag
, typically either a query or a fragment.
Generate a React propType
checking function to ensure that the passed prop is in the right form.
Supported GraphQL features
Why do you even need a library for this? Well, running a GraphQL query isn't as simple as just traversing the AST, since there are some pretty neat features that make the language a bit more complex to execute.
- Arguments
- Variables
- Aliases
- Fragments, both named and inline
-
@skip
and@include
directives
If you come across a GraphQL feature not supported here, please file an issue.
Example: Filter a nested object
import gql from 'graphql-tag';
import graphql from 'graphql-anywhere';
// I don't need all this stuff!
const gitHubAPIResponse = {
"url": "https://api.github.com/repos/octocat/Hello-World/issues/1347",
"title": "Found a bug",
"body": "I'm having a problem with this.",
"user": {
"login": "octocat",
"avatar_url": "https://github.com/images/error/octocat_happy.gif",
"url": "https://api.github.com/users/octocat",
},
"labels": [
{
"url": "https://api.github.com/repos/octocat/Hello-World/labels/bug",
"name": "bug",
"color": "f29513"
}
],
};
// Write a query that gets just the fields we want
const query = gql`
{
title
user {
login
}
labels {
name
}
}
`;
// Define a resolver that just returns a property
const resolver = (fieldName, root) => root[fieldName];
// Filter the data!
const result = graphql(
resolver,
query,
gitHubAPIResponse
);
assert.deepEqual(result, {
"title": "Found a bug",
"user": {
"login": "octocat",
},
"labels": [
{
"name": "bug",
}
],
});
Example: Generate mock data
// Write a query where the fields are types, but we alias them
const query = gql`
{
author {
name: string
age: int
address {
state: string
}
}
}
`;
// Define a resolver that uses the field name to determine the type
// Note that we get the actual name, not the alias, but the alias
// is used to determine the location in the response
const resolver = (fieldName) => ({
string: 'This is a string',
int: 5,
}[fieldName] || 'continue');
// Generate the object!
const result = graphql(
resolver,
query
);
assert.deepEqual(result, {
author: {
name: 'This is a string',
age: 5,
address: {
state: 'This is a string',
},
},
});
Example: Read from a Redux store generated with Normalizr
const data = {
result: [1, 2],
entities: {
articles: {
1: { id: 1, title: 'Some Article', author: 1 },
2: { id: 2, title: 'Other Article', author: 1 },
},
users: {
1: { id: 1, name: 'Dan' },
},
},
};
const query = gql`
{
result {
title
author {
name
}
}
}
`;
const schema = {
articles: {
author: 'users',
},
};
// This resolver is a bit more complex than others, since it has to
// correctly handle the root object, values by ID, and scalar leafs.
const resolver = (fieldName, rootValue, args, context): any => {
if (!rootValue) {
return context.result.map((id) => assign({}, context.entities.articles[id], {
__typename: 'articles',
}));
}
const typename = rootValue.__typename;
// If this field is a reference according to the schema
if (typename && schema[typename] && schema[typename][fieldName]) {
// Get the target type, and get it from entities by ID
const targetType: string = schema[typename][fieldName];
return assign({}, context.entities[targetType][rootValue[fieldName]], {
__typename: targetType,
});
}
// This field is just a scalar
return rootValue[fieldName];
};
const result = graphql(
resolver,
query,
null,
data // pass data as context since we have to access it all the time
);
// This is the non-normalized data, with only the fields we asked for in our query!
assert.deepEqual(result, {
result: [
{
title: 'Some Article',
author: {
name: 'Dan',
},
},
{
title: 'Other Article',
author: {
name: 'Dan',
},
},
],
});
Example: Generate React components
You can use the resultMapper
option to convert your results into anything you like. In this case, we convert the result fields into children for a React component:
const resolver = (fieldName, root, args) => {
if (fieldName === 'text') {
return args.value;
}
return createElement(fieldName, args);
};
const reactMapper = (childObj, root) => {
const reactChildren = Object.keys(childObj).map(key => childObj[key]);
if (root) {
return cloneElement(root, root.props, ...reactChildren);
}
return reactChildren[0];
};
function gqlToReact(query): any {
return graphql(
resolver,
query,
'',
null,
null,
{ resultMapper: reactMapper },
);
}
const query = gql`
{
div {
s1: span(id: "my-id") {
text(value: "This is text")
}
s2: span
}
}
`;
assert.equal(
renderToStaticMarkup(gqlToReact(query)),
'<div><span id="my-id">This is text</span><span></span></div>'
);