snapshot of https://github.com/ory/kratos.git (master, 2026-09-15; blobs > 131072B omitted)

courier/template/load_template.go

@@ -0,0 +1,190 @@
+// Copyright © 2023 Ory Corp
+// SPDX-License-Identifier: Apache-2.0
+
+package template
+
+import (
+	"bytes"
+	"context"
+	"embed"
+	htemplate "html/template"
+	"io"
+	"io/fs"
+	"path/filepath"
+	"text/template"
+
+	"github.com/ory/x/fetcher"
+	"github.com/ory/x/httpx"
+
+	"github.com/Masterminds/sprig/v3"
+	lru "github.com/hashicorp/golang-lru/v2"
+	"github.com/pkg/errors"
+)
+
+//go:embed courier/builtin/templates/*
+var templates embed.FS
+
+var Cache, _ = lru.New[string, Template](16)
+
+type Template interface {
+	Execute(wr io.Writer, data interface{}) error
+}
+
+type templateDependencies interface {
+	httpx.ClientProvider
+}
+
+func loadBuiltInTemplate(filesystem fs.FS, name string, html bool) (Template, error) {
+	if t, found := Cache.Get(name); found {
+		return t, nil
+	}
+
+	file, err := filesystem.Open(name)
+	if err != nil {
+		// try to fallback to bundled templates
+		var fallbackErr error
+		file, fallbackErr = templates.Open(filepath.Join("courier/builtin/templates", name))
+		if fallbackErr != nil {
+			// return original error from os.DirFS
+			return nil, errors.WithStack(err)
+		}
+	}
+
+	defer func() { _ = file.Close() }()
+
+	var b bytes.Buffer
+	if _, err := io.Copy(&b, file); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	var tpl Template
+	if html {
+		t, err := htemplate.New(name).Funcs(sprig.HtmlFuncMap()).Parse(b.String())
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+		tpl = t
+	} else {
+		t, err := template.New(name).Funcs(sprig.TxtFuncMap()).Parse(b.String())
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+		tpl = t
+	}
+
+	_ = Cache.Add(name, tpl)
+	return tpl, nil
+}
+
+func loadRemoteTemplate(ctx context.Context, d templateDependencies, url string, html bool) (t Template, err error) {
+	if t, found := Cache.Get(url); found {
+		return t, nil
+	}
+
+	f := fetcher.NewFetcher(fetcher.WithClient(d.HTTPClient(ctx)))
+	bb, err := f.FetchContext(ctx, url)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	b := bb.Bytes()
+
+	if html {
+		t, err = htemplate.New(url).Funcs(sprig.HermeticHtmlFuncMap()).Parse(string(b))
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+	} else {
+		t, err = template.New(url).Funcs(sprig.HermeticTxtFuncMap()).Parse(string(b))
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+	}
+	Cache.Add(url, t)
+
+	return t, nil
+}
+
+func loadTemplate(filesystem fs.FS, name, pattern string, html bool) (Template, error) {
+	if t, found := Cache.Get(name); found {
+		return t, nil
+	}
+
+	matches, _ := fs.Glob(filesystem, name)
+	// make sure the file exists in the fs, otherwise fallback to built in templates
+	if matches == nil {
+		return loadBuiltInTemplate(filesystem, name, html)
+	}
+
+	glob := name
+	if pattern != "" {
+		// pattern matching is used when we have more than one gotmpl for different use cases, such as i18n support
+		// e.g. some_template/template_name* will match some_template/template_name.body.en_US.gotmpl
+		matches, _ = fs.Glob(filesystem, pattern)
+		// set the glob string to match patterns
+		if matches != nil {
+			glob = pattern
+		}
+	}
+
+	var tpl Template
+	if html {
+		t, err := htemplate.New(filepath.Base(name)).Funcs(sprig.HermeticHtmlFuncMap()).ParseFS(filesystem, glob)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+		tpl = t
+	} else {
+		t, err := template.New(filepath.Base(name)).Funcs(sprig.HermeticTxtFuncMap()).ParseFS(filesystem, glob)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+		tpl = t
+	}
+
+	_ = Cache.Add(name, tpl)
+	return tpl, nil
+}
+
+func LoadText(ctx context.Context, d templateDependencies, filesystem fs.FS, name, pattern string, model interface{}, remoteURL string) (string, error) {
+	var t Template
+	var err error
+	if remoteURL != "" {
+		t, err = loadRemoteTemplate(ctx, d, remoteURL, false)
+		if err != nil {
+			return "", err
+		}
+	} else {
+		t, err = loadTemplate(filesystem, name, pattern, false)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	var b bytes.Buffer
+	if err := t.Execute(&b, model); err != nil {
+		return "", err
+	}
+	return b.String(), nil
+}
+
+func LoadHTML(ctx context.Context, d templateDependencies, filesystem fs.FS, name, pattern string, model interface{}, remoteURL string) (string, error) {
+	var t Template
+	var err error
+	if remoteURL != "" {
+		t, err = loadRemoteTemplate(ctx, d, remoteURL, true)
+		if err != nil {
+			return "", err
+		}
+	} else {
+		t, err = loadTemplate(filesystem, name, pattern, true)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	var b bytes.Buffer
+	if err := t.Execute(&b, model); err != nil {
+		return "", err
+	}
+	return b.String(), nil
+}