github.com/99designs/gqlgen@v0.17.45/graphql/context_path.go (about)

     1  package graphql
     2  
     3  import (
     4  	"context"
     5  
     6  	"github.com/vektah/gqlparser/v2/ast"
     7  )
     8  
     9  const fieldInputCtx key = "path_context"
    10  
    11  type PathContext struct {
    12  	ParentField *FieldContext
    13  	Parent      *PathContext
    14  	Field       *string
    15  	Index       *int
    16  }
    17  
    18  func (fic *PathContext) Path() ast.Path {
    19  	var path ast.Path
    20  	for it := fic; it != nil; it = it.Parent {
    21  		if it.Index != nil {
    22  			path = append(path, ast.PathIndex(*it.Index))
    23  		} else if it.Field != nil {
    24  			path = append(path, ast.PathName(*it.Field))
    25  		}
    26  	}
    27  
    28  	// because we are walking up the chain, all the elements are backwards, do an inplace flip.
    29  	for i := len(path)/2 - 1; i >= 0; i-- {
    30  		opp := len(path) - 1 - i
    31  		path[i], path[opp] = path[opp], path[i]
    32  	}
    33  
    34  	if fic.ParentField != nil {
    35  		fieldPath := fic.ParentField.Path()
    36  		return append(fieldPath, path...)
    37  
    38  	}
    39  
    40  	return path
    41  }
    42  
    43  func NewPathWithField(field string) *PathContext {
    44  	return &PathContext{Field: &field}
    45  }
    46  
    47  func NewPathWithIndex(index int) *PathContext {
    48  	return &PathContext{Index: &index}
    49  }
    50  
    51  func WithPathContext(ctx context.Context, fic *PathContext) context.Context {
    52  	if fieldContext := GetFieldContext(ctx); fieldContext != nil {
    53  		fic.ParentField = fieldContext
    54  	}
    55  	if fieldInputContext := GetPathContext(ctx); fieldInputContext != nil {
    56  		fic.Parent = fieldInputContext
    57  	}
    58  
    59  	return context.WithValue(ctx, fieldInputCtx, fic)
    60  }
    61  
    62  func GetPathContext(ctx context.Context) *PathContext {
    63  	if val, ok := ctx.Value(fieldInputCtx).(*PathContext); ok {
    64  		return val
    65  	}
    66  	return nil
    67  }
    68  
    69  func GetPath(ctx context.Context) ast.Path {
    70  	if pc := GetPathContext(ctx); pc != nil {
    71  		return pc.Path()
    72  	}
    73  	if fc := GetFieldContext(ctx); fc != nil {
    74  		return fc.Path()
    75  	}
    76  	return nil
    77  }