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Diffstat (limited to 'reader/encoding/encoding.go')
-rw-r--r-- | reader/encoding/encoding.go | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/reader/encoding/encoding.go b/reader/encoding/encoding.go new file mode 100644 index 0000000..7f726ad --- /dev/null +++ b/reader/encoding/encoding.go @@ -0,0 +1,38 @@ +// Copyright 2018 Frédéric Guillot. All rights reserved. +// Use of this source code is governed by the Apache 2.0 +// license that can be found in the LICENSE file. + +package encoding + +import ( + "bytes" + "io" + "unicode/utf8" + + "golang.org/x/net/html/charset" +) + +// CharsetReader is used when the XML encoding is specified for the input document. +// +// The document is converted in UTF-8 only if a different encoding is specified +// and the document is not already UTF-8. +// +// Several edge cases could exists: +// +// - Feeds with charset specified only in Content-Type header and not in XML document +// - Feeds with charset specified in both places +// - Feeds with charset specified only in XML document and not in HTTP header +func CharsetReader(label string, input io.Reader) (io.Reader, error) { + var buf1, buf2 bytes.Buffer + w := io.MultiWriter(&buf1, &buf2) + io.Copy(w, input) + r := bytes.NewReader(buf2.Bytes()) + + if !utf8.Valid(buf1.Bytes()) { + // Transform document to UTF-8 from the specified XML encoding. + return charset.NewReaderLabel(label, r) + } + + // The document is already UTF-8, do not do anything (avoid double-encoding) + return r, nil +} |