add ProblemOptions https://github.com/kataras/iris/issues/1335#issuecomment-521546506

Former-commit-id: 6c03439d21175f120c37a7d8dd067a0d10de837a

_examples/routing/http-errors/main.go

@@ -82,5 +82,27 @@ func problemExample(ctx iris.Context) {
 
 	// Response like JSON but with indent of "  " and
 	// content type of "application/problem+json"
-	ctx.Problem(newProductProblem("product name", "problem error details"))
+	ctx.Problem(newProductProblem("product name", "problem error details"), iris.ProblemOptions{
+		// Optional JSON renderer settings.
+		JSON: iris.JSON{
+			Indent: "  ",
+		},
+		// Sets the "Retry-After" response header.
+		//
+		// Can accept:
+		// time.Time for HTTP-Date,
+		// time.Duration, int64, float64, int for seconds
+		// or string for date or duration.
+		// Examples:
+		// time.Now().Add(5 * time.Minute),
+		// 300 * time.Second,
+		// "5m",
+		//
+		RetryAfter: 300,
+		// A function that, if specified, can dynamically set
+		// retry-after based on the request. Useful for ProblemOptions reusability.
+		// Overrides the RetryAfter field.
+		//
+		// RetryAfterFunc: func(iris.Context) interface{} { [...] }
+	})
 }

context/context.go

@@ -779,13 +779,14 @@ type Context interface {
 	// JSON marshals the given interface object and writes the JSON response.
 	JSON(v interface{}, options ...JSON) (int, error)
 	// Problem writes a JSON problem response.
-	// Order of fields are not always the same.
+	// Order of Problem fields are not always rendered the same.
 	//
 	// Behaves exactly like `Context.JSON`
-	// but with indent of " " and a content type of "application/problem+json" instead.
+	// but with default ProblemOptions.JSON indent of " " and
+	// a response content type of "application/problem+json" instead.
 	//
 	// Read more at: https://github.com/kataras/iris/wiki/Routing-error-handlers
-	Problem(v interface{}, opts ...JSON) (int, error)
+	Problem(v interface{}, opts ...ProblemOptions) (int, error)
 	// JSONP marshals the given interface object and writes the JSON response.
 	JSONP(v interface{}, options ...JSONP) (int, error)
 	// XML marshals the given interface object and writes the XML response.
@@ -3187,18 +3188,21 @@ func (ctx *context) JSON(v interface{}, opts ...JSON) (n int, err error) {
 }
 
 // Problem writes a JSON problem response.
-// Order of fields are not always the same.
+// Order of Problem fields are not always rendered the same.
 //
 // Behaves exactly like `Context.JSON`
-// but with indent of " " and a content type of "application/problem+json" instead.
+// but with default ProblemOptions.JSON indent of " " and
+// a response content type of "application/problem+json" instead.
 //
 // Read more at: https://github.com/kataras/iris/wiki/Routing-error-handlers
-func (ctx *context) Problem(v interface{}, opts ...JSON) (int, error) {
-	options := DefaultJSONOptions
+func (ctx *context) Problem(v interface{}, opts ...ProblemOptions) (int, error) {
+	options := DefaultProblemOptions
 	if len(opts) > 0 {
 		options = opts[0]
-	} else {
-		options.Indent = "  "
+		// Currently apply only if custom options passsed, otherwise,
+		// with the current settings, it's not required.
+		// This may change in the future though.
+		options.Apply(ctx)
 	}
 
 	if p, ok := v.(Problem); ok {
@@ -3209,7 +3213,7 @@ func (ctx *context) Problem(v interface{}, opts ...JSON) (int, error) {
 
 	ctx.contentTypeOnce(ContentJSONProblemHeaderValue, "")
 
-	return ctx.JSON(v, options)
+	return ctx.JSON(v, options.JSON)
 }
 
 var (

context/problem.go

@@ -2,7 +2,10 @@ package context
 
 import (
 	"fmt"
+	"math"
 	"net/http"
+	"strconv"
+	"time"
 )
 
 // Problem Details for HTTP APIs.
@@ -84,6 +87,28 @@ func (p Problem) updateTypeToAbsolute(ctx Context) {
 	}
 }
 
+const (
+	problemTempKeyPrefix = "@temp_"
+)
+
+// TempKey sets a temporary key-value pair, which is being removed
+// on the its first get.
+func (p Problem) TempKey(key string, value interface{}) Problem {
+	return p.Key(problemTempKeyPrefix+key, value)
+}
+
+// GetTempKey returns the temp value based on "key" and removes it.
+func (p Problem) GetTempKey(key string) interface{} {
+	key = problemTempKeyPrefix + key
+	v, ok := p[key]
+	if ok {
+		delete(p, key)
+		return v
+	}
+
+	return nil
+}
+
 // Key sets a custom key-value pair.
 func (p Problem) Key(key string, value interface{}) Problem {
 	p[key] = value
@@ -170,3 +195,85 @@ func (p Problem) Error() string {
 
 	return fmt.Sprintf("[%d] %s", p["status"], p["title"])
 }
+
+// DefaultProblemOptions the default options for `Context.Problem` method.
+var DefaultProblemOptions = ProblemOptions{
+	JSON: JSON{Indent: "  "},
+}
+
+// ProblemOptions the optional settings when server replies with a Problem.
+// See `Context.Problem` method and `Problem` type for more details.
+type ProblemOptions struct {
+	// JSON are the optional JSON renderer options.
+	JSON JSON
+
+	// RetryAfter sets the Retry-After response header.
+	// https://tools.ietf.org/html/rfc7231#section-7.1.3
+	// The value can be one of those:
+	// time.Time
+	// time.Duration for seconds
+	// int64, int, float64 for seconds
+	// string for duration string or for datetime string.
+	//
+	// Examples:
+	// time.Now().Add(5 * time.Minute),
+	// 300 * time.Second,
+	// "5m",
+	// 300
+	RetryAfter interface{}
+	// A function that, if specified, can dynamically set
+	// retry-after based on the request. Useful for ProblemOptions reusability.
+	// Should return time.Time, time.Duration, int64, int, float64 or string.
+	//
+	// Overrides the RetryAfter field.
+	RetryAfterFunc func(Context) interface{}
+}
+
+func parseDurationToSeconds(dur time.Duration) int64 {
+	return int64(math.Round(dur.Seconds()))
+}
+
+func (o *ProblemOptions) parseRetryAfter(value interface{}, timeLayout string) string {
+	// https://tools.ietf.org/html/rfc7231#section-7.1.3
+	// Retry-After = HTTP-date / delay-seconds
+	switch v := value.(type) {
+	case int64:
+		return strconv.FormatInt(v, 10)
+	case int:
+		return o.parseRetryAfter(int64(v), timeLayout)
+	case float64:
+		return o.parseRetryAfter(int64(math.Round(v)), timeLayout)
+	case time.Time:
+		return v.Format(timeLayout)
+	case time.Duration:
+		return o.parseRetryAfter(parseDurationToSeconds(v), timeLayout)
+	case string:
+		dur, err := time.ParseDuration(v)
+		if err != nil {
+			t, err := time.Parse(timeLayout, v)
+			if err != nil {
+				return ""
+			}
+
+			return o.parseRetryAfter(t, timeLayout)
+		}
+
+		return o.parseRetryAfter(parseDurationToSeconds(dur), timeLayout)
+	}
+
+	return ""
+}
+
+// Apply accepts a Context and applies specific response-time options.
+func (o *ProblemOptions) Apply(ctx Context) {
+	retryAfterHeaderValue := ""
+	timeLayout := ctx.Application().ConfigurationReadOnly().GetTimeFormat()
+
+	if o.RetryAfterFunc != nil {
+		retryAfterHeaderValue = o.parseRetryAfter(o.RetryAfterFunc(ctx), timeLayout)
+	} else if o.RetryAfter != nil {
+		retryAfterHeaderValue = o.parseRetryAfter(o.RetryAfter, timeLayout)
+	}
+
+	ctx.Header("Retry-After", retryAfterHeaderValue)
+}

go19.go

@@ -56,8 +56,17 @@ type (
 	//
 	// Read more at: https://github.com/kataras/iris/wiki/Routing-error-handlers
 	//
-	// It is an alias of `context.Problem` type.
+	// It is an alias of the `context#Problem` type.
 	Problem = context.Problem
+	// ProblemOptions the optional settings when server replies with a Problem.
+	// See `Context.Problem` method and `Problem` type for more details.
+	//
+	// It is an alias of the `context#ProblemOptions` type.
+	ProblemOptions = context.ProblemOptions
+	// JSON the optional settings for JSON renderer.
+	//
+	// It is an alias of the `context#JSON` type.
+	JSON = context.JSON
 
 	// Supervisor is a shortcut of the `host#Supervisor`.
 	// Used to add supervisor configurators on common Runners