Add extension interface and handlers

Author: Fontinalis

extensions.go

@@ -0,0 +1,98 @@
+package graphql
+
+import (
+	"context"
+
+	"github.com/graphql-go/graphql/gqlerrors"
+)
+
+// Extension is an interface for extensions in graphql
+type Extension interface {
+	// Init is used to help you initialize the extension
+	Init(context.Context, *Params)
+	// Name returns the name of the extension (make sure it's custom)
+	Name() string
+	// ParseDidStart ...
+	ParseDidStart(context.Context)
+	// ParseDidStart ...
+	ParseEnded(context.Context, error)
+	// ValidationDidStart ...
+	ValidationDidStart(context.Context)
+	// ValidationEnded ...
+	ValidationEnded(context.Context, []gqlerrors.FormattedError)
+	// ExecutionDidStart notifies about the start of the execution
+	ExecutionDidStart(context.Context)
+	// ExecutionEnded notifies about the end of the execution
+	ExecutionEnded(context.Context)
+	// ResolveFieldDidStart notifies about the start of the resolving of a field
+	ResolveFieldDidStart(context.Context, *ResolveInfo)
+	// ResolveFieldEnded notifies about the end of the resolving of a field
+	ResolveFieldEnded(context.Context, *ResolveInfo)
+	// HasResult returns if the extension wants to add data to the result
+	HasResult() bool
+	// GetResult returns the data that the extension wants to add to the result
+	GetResult(context.Context) interface{}
+}
+
+// handleExtensionsInits handles all the init functions for all the extensions in the schema
+func handleExtensionsInits(p *Params) {
+	for _, ext := range p.Schema.extensions {
+		ext.Init(p.Context, p)
+	}
+}
+
+// handleExtensionsParseDidStart ...
+func handleExtensionsParseDidStart(p *Params) {
+	for _, ext := range p.Schema.extensions {
+		ext.ParseDidStart(p.Context)
+	}
+}
+
+// handleExtensionsParseEnded ...
+func handleExtensionsParseEnded(p *Params, err error) {
+	for _, ext := range p.Schema.extensions {
+		ext.ParseEnded(p.Context, err)
+	}
+}
+
+// handleExtensionsValidationDidStart ...
+func handleExtensionsValidationDidStart(p *Params) {
+	for _, ext := range p.Schema.extensions {
+		ext.ValidationDidStart(p.Context)
+	}
+}
+
+// handleExtensionsValidationEnded ...
+func handleExtensionsValidationEnded(p *Params, errs []gqlerrors.FormattedError) {
+	for _, ext := range p.Schema.extensions {
+		ext.ValidationEnded(p.Context, errs)
+	}
+}
+
+// handleExecutionDidStart handles the ExecutionDidStart functions
+func handleExtensionsExecutionDidStart(p *ExecuteParams) {
+	for _, ext := range p.Schema.extensions {
+		ext.ExecutionDidStart(p.Context)
+	}
+}
+
+// handleExecutionEnded handles the notification of the extensions about the end of the execution
+func handleExtensionsExecutionEnded(p *ExecuteParams) {
+	for _, ext := range p.Schema.extensions {
+		ext.ExecutionEnded(p.Context)
+	}
+}
+
+// handleResolveFieldDidStart handles the notification of the extensions about the start of a resolve function
+func handleExtensionsResolveFieldDidStart(exts []Extension, p *executionContext, i *ResolveInfo) {
+	for _, ext := range exts {
+		ext.ResolveFieldDidStart(p.Context, i)
+	}
+}
+
+// handleResolveFieldEnded handles the notification of the extensions about the end of a resolve function
+func handleExtensionsResolveFieldEnded(exts []Extension, p *executionContext, i *ResolveInfo) {
+	for _, ext := range exts {
+		ext.ResolveFieldEnded(p.Context, i)
+	}
+}