I am trying to do something effectively like this
`query GetAllUsers($fields: [String]) {
users {
...$fields
}
}`
Where my client (currently Apollo for react) then passes in an array of fields in the variables section. The goal is to be able to pass in an array for what fields I want back, and that be interpolated to the appropriate graphql query. This currently returns a GraphQL Syntax error at $fields (expects a { but sees $ ). Is this even possible? Am I approaching this the wrong way?
One other option I had considered was invoking a JavaScript function and passing that result to query(), where the function would do something like the following:
buildQuery(fields) {
return gql`
query {
users {
${fields}
}
}`
}
This however feels like an unecessary workaround.
Comments summary:
Non standard requirements requires workarounds ;)
You can use fragments (for predefined fieldsets) but they probably won't be freely granular (field level).
Variables are definitely not for query definition (but for variables used in query).
Daniel's suggestion: gql-query-builder
It seams that graphQL community is great and full of people working on all possible use cases ... it's enough to search for solutions or ask on SO ;)
Related
For my GraphQL app I'd like to save logs of certain resolved fields. Because the users can view these logs themselves, should that be considered apart of a mutation instead of a query?
Since it's not the application's focus I'd assume that using a mutation is overkill, but I'm not sure if there's some sort of side effects I'm going to run into by modeling it in such a way.
The other questions I've read didn't really answer this question, so sorry if this seems like a duplicate.
Conceptually Graphql Queries & Mutations do the same thing but however differ in the way the resolvers are executed.
For the following Queries:
{
user {
name
}
posts {
title
}
}
The GraphQL implementation has the freedom to execute the field entries in whatever order it deems optimal. see here.
For the following Mutations:
{
createUser(name: $String) {
id
}
addPost(title: $String) {
id
}
}
The GraphQL implementation would execute each Mutation sequentially. see here
Par from this, the Mutation keyword is just a bit of syntax to say "hey this is gonna edit or create something". I think here, in your case, its a better decision to perform a Query & store the event in your Audit log. Exposing the fact that the Query stores an audit log is an implementation-specific detail & clients shouldn't know about it.
I'm relatively new to GraphQL so please bear with me ...
That said, I'm writing an app in node.js to push/pull data from two disparate systems, one of which has an API written in GraphQL.
For the Graph system, I have, something like, the following types defined for me:
Time {
TimeId: Int
TaskId: Int
ProjectId: Int
Project: [Project]
TimeInSeconds: Int
Timestamp: Date
}
and
Task {
TaskId: Int
TaskName: String
TaskDescription: String
}
Where Project is another type whose definition isn't important, only that it is included in the type definition as a field...
What I would like to know is if there is a way to write a query for Time in such a way that I can include the Task type's values in my results in a similar way as the values for the Project type are included in the definition?
I am using someone else's API and do not have the ability to define my own custom types. I can write my own limited queries, but I don't know if the limits are set by the devs that wrote the API or my limited ability with GraphQL.
My suspicion is that I cannot and that I will have to query both separately and combine them after the fact, but I wanted to check here just in case.
Unfortunately, unless the Time type exposes some kind of field to fetch the relevant Task, you won't be able to query for it within the same request. You can include multiple queries within a single GraphQL request; however, they are ran in parallel, which means you won't be able to use the TaskId value returned by one query as a variable used in another query.
This sort of problem is best solved by modifying the schema, but if that's not an option then unfortunately the only other option is to make each request sequentially and then combine the results client-side.
Can the below be achieved with graph ql:
we have getusers() / getusers(id=3) / getusers(name='John). Can we use same query to accept different parameters (arguments)?
I assume you mean something like:
type Query {
getusers: [User]!
getusers(id: ID!): User
getusers(name: String!): User
}
IMHO the first thing to do is try. You should get an error saying that Query.getusers can only be defined once, which would answer your question right away.
Here's the actual spec saying that such a thing is not valid: http://facebook.github.io/graphql/June2018/#example-5e409
Quote:
Each named operation definition must be unique within a document when
referred to by its name.
Solution
From what I've seen, the most GraphQL'y way to create such an API is to define a filter input type, something like this:
input UserFilter {
ids: [ID]
names: [String]
}
and then:
type Query {
users(filter: UserFilter)
}
The resolver would check what filters were passed (if any) and query the data accordingly.
This is very simple and yet really powerful as it allows the client to query for an arbitrary number of users using an arbitrary filter. As a back-end developer you may add more options to UserFilter later on, including some pagination options and other cool things, while keeping the old API intact. And, of course, it is up to you how flexible you want this API to be.
But why is it like that?
Warning! I am assuming some things here and there, and might be wrong.
GraphQL is only a logical API layer, which is supposed to be server-agnostic. However, I believe that the original implementation was in JavaScript (citation needed). If you then consider the technical aspects of implementing a GraphQL API in JS, you might get an idea about why it is the way it is.
Each query points to a resolver function. In JS resolvers are simple functions stored inside plain objects at paths specified by the query/mutation/subscription name. As you may know, JS objects can't have more than one path with the same name. This means that you could only define a single resolver for a given query name, thus all three getusers would map to the same function Query.getusers(obj, args, ctx, info) anyway.
So even if GraphQL allowed for fields with the same name, the resolver would have to explicitly check for whatever arguments were passed, i.e. if (args.id) { ... } else if (args.name) { ... }, etc., thus partially defeating the point of having separate endpoints. On the other hand, there is an overall better (particularly from the client's perspective) way to define such an API, as demonstrated above.
Final note
GraphQL is conceptually different from REST, so it doesn't make sense to think in terms of three endpoints (/users, /users/:id and /users/:name), which is what I guess you were doing. A paradigm shift is required in order to unveil the full potential of the language.
a request of the type works:
Query {
first:getusers(),
second:getusers(id=3)
third:getusers(name='John)
}
I have a GraphQl API for listing a bunch of items, and I can query it perfectly etc.
But now I'd like to query for a subset of that list where one property can have 'all possible values except one specific one'.
For example, I want to query something like this:
{
items(status: !"Unwanted"){
id
}
}
That exclamation mark obviously doesn't work, but it illustrates what I am after.
Can't find any information about this online.
Does anybody know of a way to do this?
I would really hate having to enumerate all possible wanted values instead of just excluding the one unwanted value. This would be really bad design and is not scalable.
Thanks.
Use ne :
{
items(filter: {status: {ne: "Unwanted"}}){
id
}
}
If you can define the schema (implement the server) then you can add a second argument like statusExcept to the items field. Then in the resolve method check if status or statusExcept was set and deliver the items according to that.
It the server API is fixed there is afaik nothing that you can do except getting everything and filter on the client.
Using GraphQL version 4.3.2 the syntax has changed and you will need to use notIn
{
items(filter: {status: {notIn: "Unwanted"}}){
id
}
}
Pardon the naive question, but I've looked all over for the answer and all I've found is either vague or makes no sense to me. Take this example from the GraphQL spec:
query getZuckProfile($devicePicSize: Int) {
user(id: 4) {
id
name
profilePic(size: $devicePicSize)
}
}
What is the point of naming this query getZuckProfile? I've seen something about GraphQL documents containing multiple operations. Does naming queries affect the returned data somehow? I'd test this out myself, but I don't have a server and dataset I can easily play with to experiment. But it would be good if something in some document somewhere could clarify this--thus far all of the examples are super simple single queries, or are queries that are named but that don't explain why they are (other than "here's a cool thing you can do.") What benefits do I get from naming queries that I don't have when I send a single, anonymous query per request?
Also, regarding mutations, I see in the spec:
mutation setName {
setName(name: "Zuck") {
newName
}
}
In this case, you're specifying setName twice. Why? I get that one of these is the field name of the mutation and is needed to match it to the back-end schema, but why not:
mutation {
setName(name: "Zuck") {
...
What benefit do I get specifying the same name twice? I get that the first is likely arbitrary, but why isn't it noise? I have to be missing something obvious, but nothing I've found thus far has cleared it up for me.
The query name doesn't have any meaning on the server whatsoever. It's only used for clients to identify the responses (since you can send multiple queries/mutations in a single request).
In fact, you can send just an anonymous query object if that's the only thing in the GraphQL request (and doesn't have any parameters):
{
user(id: 4) {
id
name
profilePic(size: 200)
}
}
This only works for a query, not mutation.
EDIT:
As #orta notes below, the name could also be used by the server to identify a persistent query. However, this is not part of the GraphQL spec, it's just a custom implementation on top.
We use named queries so that they can be monitored consistently, and so that we can do persistent storage of a query. The duplication is there for query variables to fill the gaps.
As an example:
query getArtwork($id: String!) {
artwork(id: $id) {
title
}
}
You can run it against the Artsy GraphQL API here
The advantage is that the same query each time, not a different string because the query variables are the bit that differs. This means you can build tools on top of those queries because you can treat them as immutable.