82 lines
2.7 KiB
Markdown
82 lines
2.7 KiB
Markdown
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# Data URL Schemes for Go [](https://app.wercker.com/project/bykey/6f9a2e144dfcc59e862c52459b452928) [](https://godoc.org/github.com/vincent-petithory/dataurl)
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This package parses and generates Data URL Schemes for the Go language, according to [RFC 2397](http://tools.ietf.org/html/rfc2397).
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Data URLs are small chunks of data commonly used in browsers to display inline data,
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typically like small images, or when you use the FileReader API of the browser.
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Common use-cases:
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* generate a data URL out of a `string`, `[]byte`, `io.Reader` for inclusion in HTML templates,
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* parse a data URL sent by a browser in a http.Handler, and do something with the data (save to disk, etc.)
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* ...
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Install the package with:
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~~~
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go get github.com/vincent-petithory/dataurl
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~~~
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## Usage
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~~~ go
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package main
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import (
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"github.com/vincent-petithory/dataurl"
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"fmt"
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)
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func main() {
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dataURL, err := dataurl.DecodeString(`data:text/plain;charset=utf-8;base64,aGV5YQ==`)
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if err != nil {
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fmt.Println(err)
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return
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}
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fmt.Printf("content type: %s, data: %s\n", dataURL.MediaType.ContentType(), string(dataURL.Data))
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// Output: content type: text/plain, data: heya
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}
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~~~
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From a `http.Handler`:
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~~~ go
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func handleDataURLUpload(w http.ResponseWriter, r *http.Request) {
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dataURL, err := dataurl.Decode(r.Body)
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defer r.Body.Close()
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if err != nil {
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http.Error(w, err.Error(), http.StatusBadRequest)
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return
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}
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if dataURL.ContentType() == "image/png" {
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ioutil.WriteFile("image.png", dataURL.Data, 0644)
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} else {
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http.Error(w, "not a png", http.StatusBadRequest)
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}
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}
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~~~
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## Command
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For convenience, a `dataurl` command is provided to encode/decode dataurl streams.
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~~~
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dataurl - Encode or decode dataurl data and print to standard output
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Usage: dataurl [OPTION]... [FILE]
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dataurl encodes or decodes FILE or standard input if FILE is - or omitted, and prints to standard output.
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Unless -mimetype is used, when FILE is specified, dataurl will attempt to detect its mimetype using Go's mime.TypeByExtension (http://golang.org/pkg/mime/#TypeByExtension). If this fails or data is read from STDIN, the mimetype will default to application/octet-stream.
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Options:
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-a=false: encode data using ascii instead of base64
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-ascii=false: encode data using ascii instead of base64
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-d=false: decode data instead of encoding
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-decode=false: decode data instead of encoding
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-m="": force the mimetype of the data to encode to this value
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-mimetype="": force the mimetype of the data to encode to this value
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~~~
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## Contributing
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Feel free to file an issue/make a pull request if you find any bug, or want to suggest enhancements.
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