diff options
Diffstat (limited to 'parser/frontmatter.go')
-rw-r--r-- | parser/frontmatter.go | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/parser/frontmatter.go b/parser/frontmatter.go new file mode 100644 index 000000000..6ace0031d --- /dev/null +++ b/parser/frontmatter.go @@ -0,0 +1,129 @@ +// Copyright © 2013 Steve Francia <spf@spf13.com>. +// +// Licensed under the Simple Public License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// http://opensource.org/licenses/Simple-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package parser + +import ( + "bytes" + "encoding/json" + "fmt" + + "github.com/BurntSushi/toml" + "launchpad.net/goyaml" +) + +type FrontmatterType struct { + markstart, markend []byte + Parse func([]byte) (interface{}, error) + includeMark bool +} + +func InterfaceToFrontMatter(in interface{}, mark rune) ([]byte, error) { + if in == nil { + return []byte{}, fmt.Errorf("input was nil") + } + + b := new(bytes.Buffer) + + switch mark { + case rune(YAML_LEAD[0]): + _, err := b.Write([]byte(YAML_DELIM_UNIX)) + if err != nil { + return nil, err + } + by, err := goyaml.Marshal(in) + if err != nil { + return nil, err + } + b.Write(by) + _, err = b.Write([]byte(YAML_DELIM_UNIX)) + if err != nil { + return nil, err + } + return b.Bytes(), nil + case rune(TOML_LEAD[0]): + _, err := b.Write([]byte(TOML_DELIM_UNIX)) + if err != nil { + return nil, err + } + + err = toml.NewEncoder(b).Encode(in) + if err != nil { + fmt.Println("toml encoder failed", in) + fmt.Println(err) + return nil, err + } + _, err = b.Write([]byte("\n" + TOML_DELIM_UNIX)) + if err != nil { + return nil, err + } + return b.Bytes(), nil + case rune(JSON_LEAD[0]): + by, err := json.MarshalIndent(in, "", " ") + if err != nil { + fmt.Println("json encoder failed", in) + fmt.Println(err) + return nil, err + } + b.Write(by) + _, err = b.Write([]byte("\n")) + if err != nil { + return nil, err + } + return b.Bytes(), nil + default: + return nil, fmt.Errorf("Unsupported Format provided") + } +} + +func DetectFrontMatter(mark rune) (f *FrontmatterType) { + switch mark { + case '-': + return &FrontmatterType{[]byte(YAML_DELIM), []byte(YAML_DELIM), HandleYamlMetaData, false} + case '+': + return &FrontmatterType{[]byte(TOML_DELIM), []byte(TOML_DELIM), HandleTomlMetaData, false} + case '{': + return &FrontmatterType{[]byte{'{'}, []byte{'}'}, HandleJsonMetaData, true} + default: + return nil + } +} + +func HandleTomlMetaData(datum []byte) (interface{}, error) { + m := map[string]interface{}{} + datum = removeTomlIdentifier(datum) + if _, err := toml.Decode(string(datum), &m); err != nil { + return m, err + } + return m, nil +} + +func removeTomlIdentifier(datum []byte) []byte { + return bytes.Replace(datum, []byte(TOML_DELIM), []byte(""), -1) +} + +func HandleYamlMetaData(datum []byte) (interface{}, error) { + m := map[string]interface{}{} + if err := goyaml.Unmarshal(datum, &m); err != nil { + return m, err + } + return m, nil +} + +func HandleJsonMetaData(datum []byte) (interface{}, error) { + var f interface{} + if err := json.Unmarshal(datum, &f); err != nil { + return f, err + } + return f, nil +} |