github.com/maeglindeveloper/gqlgen@v0.13.1-0.20210413081235-57808b12a0a0/example/todo/todo.go (about)

     1  //go:generate go run ../../testdata/gqlgen.go
     2  
     3  package todo
     4  
     5  import (
     6  	"context"
     7  	"errors"
     8  	"fmt"
     9  	"time"
    10  
    11  	"github.com/99designs/gqlgen/graphql"
    12  	"github.com/mitchellh/mapstructure"
    13  )
    14  
    15  var you = &User{ID: 1, Name: "You"}
    16  var them = &User{ID: 2, Name: "Them"}
    17  
    18  type ckey string
    19  
    20  func getUserId(ctx context.Context) int {
    21  	if id, ok := ctx.Value(ckey("userId")).(int); ok {
    22  		return id
    23  	}
    24  	return you.ID
    25  }
    26  
    27  func New() Config {
    28  	c := Config{
    29  		Resolvers: &resolvers{
    30  			todos: []*Todo{
    31  				{ID: 1, Text: "A todo not to forget", Done: false, owner: you},
    32  				{ID: 2, Text: "This is the most important", Done: false, owner: you},
    33  				{ID: 3, Text: "Somebody else's todo", Done: true, owner: them},
    34  				{ID: 4, Text: "Please do this or else", Done: false, owner: you},
    35  			},
    36  			lastID: 4,
    37  		},
    38  	}
    39  	c.Directives.HasRole = func(ctx context.Context, obj interface{}, next graphql.Resolver, role Role) (interface{}, error) {
    40  		switch role {
    41  		case RoleAdmin:
    42  			// No admin for you!
    43  			return nil, nil
    44  		case RoleOwner:
    45  			ownable, isOwnable := obj.(Ownable)
    46  			if !isOwnable {
    47  				return nil, fmt.Errorf("obj cant be owned")
    48  			}
    49  
    50  			if ownable.Owner().ID != getUserId(ctx) {
    51  				return nil, fmt.Errorf("you dont own that")
    52  			}
    53  		}
    54  
    55  		return next(ctx)
    56  	}
    57  	c.Directives.User = func(ctx context.Context, obj interface{}, next graphql.Resolver, id int) (interface{}, error) {
    58  		return next(context.WithValue(ctx, ckey("userId"), id))
    59  	}
    60  	return c
    61  }
    62  
    63  type resolvers struct {
    64  	todos  []*Todo
    65  	lastID int
    66  }
    67  
    68  func (r *resolvers) MyQuery() MyQueryResolver {
    69  	return (*QueryResolver)(r)
    70  }
    71  
    72  func (r *resolvers) MyMutation() MyMutationResolver {
    73  	return (*MutationResolver)(r)
    74  }
    75  
    76  type QueryResolver resolvers
    77  
    78  func (r *QueryResolver) Todo(ctx context.Context, id int) (*Todo, error) {
    79  	time.Sleep(220 * time.Millisecond)
    80  
    81  	if id == 666 {
    82  		panic("critical failure")
    83  	}
    84  
    85  	for _, todo := range r.todos {
    86  		if todo.ID == id {
    87  			return todo, nil
    88  		}
    89  	}
    90  	return nil, errors.New("not found")
    91  }
    92  
    93  func (r *QueryResolver) LastTodo(ctx context.Context) (*Todo, error) {
    94  	if len(r.todos) == 0 {
    95  		return nil, errors.New("not found")
    96  	}
    97  	return r.todos[len(r.todos)-1], nil
    98  }
    99  
   100  func (r *QueryResolver) Todos(ctx context.Context) ([]*Todo, error) {
   101  	return r.todos, nil
   102  }
   103  
   104  type MutationResolver resolvers
   105  
   106  func (r *MutationResolver) CreateTodo(ctx context.Context, todo TodoInput) (*Todo, error) {
   107  	newID := r.id()
   108  
   109  	newTodo := &Todo{
   110  		ID:    newID,
   111  		Text:  todo.Text,
   112  		owner: you,
   113  	}
   114  
   115  	if todo.Done != nil {
   116  		newTodo.Done = *todo.Done
   117  	}
   118  
   119  	r.todos = append(r.todos, newTodo)
   120  
   121  	return newTodo, nil
   122  }
   123  
   124  func (r *MutationResolver) UpdateTodo(ctx context.Context, id int, changes map[string]interface{}) (*Todo, error) {
   125  	var affectedTodo *Todo
   126  
   127  	for i := 0; i < len(r.todos); i++ {
   128  		if r.todos[i].ID == id {
   129  			affectedTodo = r.todos[i]
   130  			break
   131  		}
   132  	}
   133  
   134  	if affectedTodo == nil {
   135  		return nil, nil
   136  	}
   137  
   138  	err := mapstructure.Decode(changes, affectedTodo)
   139  	if err != nil {
   140  		panic(err)
   141  	}
   142  
   143  	return affectedTodo, nil
   144  }
   145  
   146  func (r *MutationResolver) id() int {
   147  	r.lastID++
   148  	return r.lastID
   149  }