Remove HandlerError

TODO.md

@@ -1,14 +1,17 @@
 # TODO
 
+- [ ] Dot Provider system
+    - [ ] Accept configuration from JSON
+    - [ ] Accept configuration from Caddyfile
+    - [ ] Env?
 - [ ] Update documentation
     - [ ] Readme docs
     - [ ] Go API docs
     - [ ] CLI docs
 - [ ] Downgrade to go 1.21
-- [ ] Use go-arg library for arg parsing
-    - [ ] Fix go-arg embedded structs or don't use them https://github.com/alexflint/go-arg/issues/242
 - [ ] Add ServeTemplate that delays template rendering until requested by
-  http.ServeContent to optimize cache behavior.
+  http.ServeContent to optimize cache behavior. Something like
+  https://github.com/spatialcurrent/go-lazy ?
 - [ ] Add NATS module:
     - [ ] Subscribe to subject, loop on receive to send via open SSE connection
     - [ ] Publish message to subject
@@ -56,9 +59,14 @@
 
 ## v0.5 beta - Mar 2024
 
-- [x] Create system for customizing template dot value. Potential modules: Config/DB/FS/NATS/mail
+- Dot Provider system
+    - [x] Create system for customizing template dot value
+    - [x] Convert existing modules
+    - [x] Accept configuration from cli
 - [x] Get rid of Server/Instance interfaces, expose structs directly
 - [x] Catch servemux addhandler panics and return an error instead
+- [x] Use go-arg library for arg parsing
+    - [x] Fix go-arg embedded structs or don't use them https://github.com/alexflint/go-arg/issues/242
 
 ## v0.4 - Mar 2024
 

dot.go

@@ -12,31 +12,6 @@ import (
 	"sync"
 )
 
-/*
-
-Name DotProvider
-
-- Context providers should be able to add methods and fields directly to the
-  root context {{.}}, by having an anonymous field
-- Context providers should have customizable name
-
-- Should have a default
-- Users should be able to override name
-
-
-Needs to get configuration from:
-
-- Args
-	- Parse args with https://pkg.go.dev/github.com/alexflint/go-arg#Parse
-	- https://github.com/alexflint/go-arg/issues/220
-	- Format:   -c "Tx:sql:sqlite3:file"
-- Json
-- Caddyfile
-- Manual go configuration
-- env? defaults?
-
-*/
-
 var registrations map[string]RegisteredDotProvider = make(map[string]RegisteredDotProvider)
 
 func RegisterDot(r RegisteredDotProvider) {

dot_resp.go

@@ -2,7 +2,6 @@ package xtemplate
 
 import (
 	"context"
-	"errors"
 	"log/slog"
 	"maps"
 	"net/http"
@@ -14,80 +13,73 @@ import (
 
 type responseDotProvider struct{}
 
-func (responseDotProvider) Type() reflect.Type { return reflect.TypeOf(ResponseDot{}) }
+func (responseDotProvider) Type() reflect.Type { return reflect.TypeOf(responseDot{}) }
 
 func (responseDotProvider) Value(log *slog.Logger, _ context.Context, w http.ResponseWriter, r *http.Request) (reflect.Value, error) {
-	return reflect.ValueOf(ResponseDot{Header: make(http.Header), status: http.StatusOK, w: w, r: r, log: log}), nil
+	return reflect.ValueOf(responseDot{Header: make(http.Header), status: http.StatusOK, w: w, r: r, log: log}), nil
 }
 
 func (responseDotProvider) Cleanup(v reflect.Value, err error) error {
-	d := v.Interface().(ResponseDot)
-	var handlerErr HandlerError
+	d := v.Interface().(responseDot)
 	if err == nil {
 		maps.Copy(d.w.Header(), d.Header)
 		d.w.WriteHeader(d.status)
-		return nil
-	} else if errors.As(err, &handlerErr) {
-		d.log.Debug("forwarding response handling", slog.Any("handler", handlerErr))
-		handlerErr.ServeHTTP(d.w, d.r)
-		return nil
-	} else {
-		return err
 	}
+	return err
 }
 
 var _ CleanupDotProvider = responseDotProvider{}
 
-type ResponseDot struct {
+type responseDot struct {
 	http.Header
 	status int
 	w      http.ResponseWriter
 	r      *http.Request
 	log    *slog.Logger
 }
 
-// ServeContent aborts execution of the template and instead responds to the request with content
-func (d *ResponseDot) ServeContent(path_ string, modtime time.Time, content string) (string, error) {
-	return "", NewHandlerError("ServeContent", func(w http.ResponseWriter, r *http.Request) {
-		path_ = path.Clean(path_)
-
-		d.log.Debug("serving content response", slog.String("path", path_))
-
-		http.ServeContent(w, r, path_, modtime, strings.NewReader(content))
-	})
+// ServeContent aborts execution of the template and instead responds to the
+// request with content with any headers set by AddHeader and SetHeader so far
+// but ignoring SetStatus.
+func (d *responseDot) ServeContent(path_ string, modtime time.Time, content string) (string, error) {
+	path_ = path.Clean(path_)
+	d.log.Debug("serving content response", slog.String("path", path_))
+	maps.Copy(d.w.Header(), d.Header)
+	http.ServeContent(d.w, d.r, path_, modtime, strings.NewReader(content))
+	return "", ReturnError{}
 }
 
 // AddHeader adds a header field value, appending val to
 // existing values for that field. It returns an
 // empty string.
-func (h ResponseDot) AddHeader(field, val string) string {
+func (h responseDot) AddHeader(field, val string) string {
 	h.Header.Add(field, val)
 	return ""
 }
 
 // SetHeader sets a header field value, overwriting any
 // other values for that field. It returns an
 // empty string.
-func (h ResponseDot) SetHeader(field, val string) string {
+func (h responseDot) SetHeader(field, val string) string {
 	h.Header.Set(field, val)
 	return ""
 }
 
 // DelHeader deletes a header field. It returns an empty string.
-func (h ResponseDot) DelHeader(field string) string {
+func (h responseDot) DelHeader(field string) string {
 	h.Header.Del(field)
 	return ""
 }
 
 // SetStatus sets the HTTP response status. It returns an empty string.
-func (h *ResponseDot) SetStatus(status int) string {
+func (h *responseDot) SetStatus(status int) string {
 	h.status = status
 	return ""
 }
 
 // ReturnStatus sets the HTTP response status and exits template rendering
 // immediately.
-func (h *ResponseDot) ReturnStatus(status int) (string, error) {
+func (h *responseDot) ReturnStatus(status int) (string, error) {
 	h.status = status
 	return "", ReturnError{}
 }

funcs.go

@@ -25,7 +25,6 @@ var xtemplateFuncs template.FuncMap = template.FuncMap{
 	"sanitizeHtml":     funcSanitizeHtml,
 	"markdown":         funcMarkdown,
 	"splitFrontMatter": funcSplitFrontMatter,
-	"abortWithStatus":  funcAbortWithStatus,
 	"return":           funcReturn,
 	"status":           funcStatus,
 	"humanize":         funcHumanize,
@@ -107,14 +106,6 @@ func funcReturn() (string, error) {
 	return "", ReturnError{}
 }
 
-// funcAbortWithStatus stops rendering the reponse template and immediately returns the status indicated.
-// Example usage: `{{if not (fileExists $includeFile)}}{{abortWithStatus 404}}{{end}}`
-func funcAbortWithStatus(statusCode int) (struct{}, error) {
-	return struct{}{}, NewHandlerError("abort", func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(statusCode)
-	})
-}
-
 // See status.go
 var validStatus = map[string]int{
 	"Continue":           http.StatusContinue,

handlers.go

@@ -222,29 +222,3 @@ func negiotiateEncoding(acceptHeaders []string, encodings []encodingInfo) (*enco
 	}
 	return &encodings[maxqIdx], err
 }
-
-// HandlerError is a special error that hijacks xtemplate's normal response
-// handling and passes response handling off to the ServeHTTP method on this
-// error value instead.
-type HandlerError interface {
-	Error() string
-	ServeHTTP(w http.ResponseWriter, r *http.Request)
-}
-
-var _ error = HandlerError(nil)
-var _ http.Handler = HandlerError(nil)
-
-// NewHandlerError returns a new HandlerError based on a string and a function
-// that matches the ServeHTTP signature.
-func NewHandlerError(name string, fn func(w http.ResponseWriter, r *http.Request)) HandlerError {
-	return funcHandlerError{name, fn}
-}
-
-type funcHandlerError struct {
-	name string
-	fn   func(w http.ResponseWriter, r *http.Request)
-}
-
-func (fhe funcHandlerError) Error() string { return fhe.name }
-
-func (fhe funcHandlerError) ServeHTTP(w http.ResponseWriter, r *http.Request) { fhe.fn(w, r) }

providers/fs.go

@@ -54,12 +54,14 @@ var _ encoding.TextUnmarshaler = &FSDot{}
 var _ encoding.TextMarshaler = &FSDot{}
 
 func (fs FSDot) Value(log *slog.Logger, sctx context.Context, w http.ResponseWriter, r *http.Request) (reflect.Value, error) {
-	return reflect.ValueOf(fsDot{fs, log}), nil
+	return reflect.ValueOf(fsDot{fs, log, w, r}), nil
 }
 
 type fsDot struct {
 	fs  fs.FS
 	log *slog.Logger
+	w   http.ResponseWriter
+	r   *http.Request
 }
 
 var bufPool = sync.Pool{
@@ -145,24 +147,24 @@ func (c *fsDot) FileExists(filename string) (bool, error) {
 // ServeFile aborts execution of the template and instead responds to the
 // request with the content of the file at path_
 func (c *fsDot) ServeFile(path_ string) (string, error) {
-	return "", xtemplate.NewHandlerError("ServeFile", func(w http.ResponseWriter, r *http.Request) {
-		path_ = path.Clean(path_)
-
-		c.log.Debug("serving file response", slog.String("path", path_))
-
-		file, err := c.fs.Open(path_)
-		if err != nil {
-			c.log.Debug("failed to open file", slog.Any("error", err), slog.String("path", path_))
-			http.Error(w, "internal server error", 500)
-			return
-		}
-		defer file.Close()
-
-		stat, err := file.Stat()
-		if err != nil {
-			c.log.Debug("error getting stat of file", slog.Any("error", err), slog.String("path", path_))
-		}
-
-		http.ServeContent(w, r, path_, stat.ModTime(), file.(io.ReadSeeker))
-	})
+	path_ = path.Clean(path_)
+
+	c.log.Debug("serving file response", slog.String("path", path_))
+
+	file, err := c.fs.Open(path_)
+	if err != nil {
+		return "", fmt.Errorf("failed to open file at path '%s': %w", path_, err)
+	}
+	defer file.Close()
+
+	stat, err := file.Stat()
+	if err != nil {
+		c.log.Debug("error getting stat of file", slog.Any("error", err), slog.String("path", path_))
+	}
+
+	// TODO: Handle setting headers.
+
+	http.ServeContent(c.w, c.r, path_, stat.ModTime(), file.(io.ReadSeeker))
+
+	return "", xtemplate.ReturnError{}
 }