dataurl

README

go-dataurl

A library that provides tools to work with data URLs, as defined by RFC 2397, for the Go programming language.

Here are some data URL examples:

• data:,Hello%20world!

• data:text/html;base64,PGh0bWw+PGhlYWQ+PHRpdGxlPlRlc3Q8L3RpdGxlPjwvaGVhZD48Ym9keT48cD5UaGlzIGlzIGEgdGVzdDwvYm9keT48L2h0bWw+Cg==

• data:text/plain;charset=utf-8,This%20is%20a%20test%21

• data:;charset=utf-8,This%20is%20a%20test%21

• data:text/plain,This%20is%20a%20test%21

• data:,This%20is%20a%20test%21

• data:text/plain;charset=utf-8;base64,VGhpcyBpcyBhIHRlc3Qh

• data:;charset=utf-8;base64,VGhpcyBpcyBhIHRlc3Qh

• data:text/plain;base64,VGhpcyBpcyBhIHRlc3Qh

• data:;base64,VGhpcyBpcyBhIHRlc3Qh

Documention

Online documentation, which includes examples, can be found at: http://godoc.org/github.com/reiver/go-dataurl

Example

parcel, err := dataurl.Parse("data:,Hello%20world!")
if nil != err {
    //@TODO
}

fmt.Printf("Content: %q \n", parcel.String()) // parcel.String() == "Hello world!"
fmt.Printf("Media Type: %q \n", parcel.MediaType()) // parcel.MediaType() == "text/plain;charset=US-ASCII"

Another example

// Note that dataurl.MustPasre() will panic() if there is an
// error when trying to parse the data URL!
parcel := dataurl.MustParse("data:,Hello%20world!")

fmt.Printf("Content: %q \n", parcel.String()) // parcel.String() == "Hello world!"
fmt.Printf("Media Type: %q \n", parcel.MediaType()) // parcel.MediaType() == "text/plain;charset=US-ASCII"

Documentation

Overview

go-dataurl

Package dataurl provides tools to work with data URLs, as defined by RFC 2397 ( http://www.faqs.org/rfcs/rfc2397.html ).

Here are some data URL examples:

data:,Hello%20world!

data:text/html;base64,PGh0bWw+PGhlYWQ+PHRpdGxlPlRlc3Q8L3RpdGxlPjwvaGVhZD48Ym9keT48cD5UaGlzIGlzIGEgdGVzdDwvYm9keT48L2h0bWw+Cg==

data:text/plain;charset=utf-8,This%20is%20a%20test%21
data:;charset=utf-8,This%20is%20a%20test%21
data:text/plain,This%20is%20a%20test%21
data:,This%20is%20a%20test%21

data:text/plain;charset=utf-8;base64,VGhpcyBpcyBhIHRlc3Qh
data:;charset=utf-8;base64,VGhpcyBpcyBhIHRlc3Qh
data:text/plain;base64,VGhpcyBpcyBhIHRlc3Qh
data:;base64,VGhpcyBpcyBhIHRlc3Qh

Example Usage

parcel, err := dataurl.Parse("data:,Hello%20world!")
if nil != err {
	//@TODO
}

fmt.Printf("Content: %q \n", parcel.String()) // parcel.String() == "Hello world!"
fmt.Printf("Media Type: %q \n", parcel.MediaType()) // parcel.MediaType() == "text/plain;charset=US-ASCII"

Another Example Usage

// Note that dataurl.MustPasre() will panic() if there is an
// error when trying to parse the data URL!
parcel := dataurl.MustParse("data:,Hello%20world!") // parcel.String() == "Hello world!"

fmt.Printf("Content: %q \n", parcel.String())
fmt.Printf("Media Type: %q \n", parcel.MediaType()) // parcel.MediaType() == "text/plain;charset=US-ASCII"

Index

• type BadMediaTypeComplainer
• type BadRequestComplainer
• type InternalErrorComplainer
• type NotADataUrlComplainer
• type Parcel
  • func MustParse(dataURL string) Parcel
  • func Parse(dataURL string) (Parcel, error)
• type SyntaxErrorComplainer

Types

type BadMediaTypeComplainer

type BadMediaTypeComplainer interface {
	BadRequestComplainer
	BadMediaTypeComplainer()
	WrappedError() error
}

type BadRequestComplainer

type BadRequestComplainer interface {
	error
	BadRequestComplainer()
}

type InternalErrorComplainer

type InternalErrorComplainer interface {
	error
	InternalErrorComplainer()
}

type NotADataUrlComplainer

type NotADataUrlComplainer interface {
	BadRequestComplainer
	NotADataUrlComplainer()
}

type Parcel

type Parcel interface {
	Bytes() []byte
	Reader() io.Reader
	Runes() []rune
	String() string

	MediaType() string
}

Parcel is used to contain the result of parsing a Data URL.

It provides the Bytes, Reader, Runes and String methods; used to retrieve the contents of a Data URL in []byte, io.Reader, []rune and string formats, respectively.

It also provides the MediaType method; used to retrieve the (explicitly or implicitly) declared 'media type' of a Data URL.

For example:

parcel, err := dataurl.Parse("data:,Hello")
if nil != err {
	//@TODO
}

contents := parcel.String() // == "Hello"

mediaType := parcel.MediaType() // == "text/plain;charset=US-ASCII"

Also, for example:

parcel, err := dataurl.Parse("data:application/x-apple-banana-cherry,Hello")
if nil != err {
	//@TODO
}

contents := parcel.String() // == "Hello"

mediaType := parcel.MediaType() // == "application/x-apple-banana-cherry;charset=US-ASCII"

func MustParse

func MustParse(dataURL string) Parcel

MustParse is like dataurl.Parse(), expect it only returns a Parcel, and panic()s if there was an error parsing 'dataURL'.

Example usage:

parcel := dataurl.MustParse("data:,Hello%20world!")

fmt.Println(parcel.String()) // parcel.String() == "Hello world!"

func Parse

func Parse(dataURL string) (Parcel, error)

Parse parses a data URL contained in parameter 'dataURL', and if it contained a valid data URL, returns a Parcel, else returns an error.

Example usage:

parcel, err := dataurl.Parse("data:,Hello%20world!")
if nil != err {
	//@TODO
}

fmt.Println(parcel.String()) // parcel.String() == "Hello world!"

type SyntaxErrorComplainer

type SyntaxErrorComplainer interface {
	BadRequestComplainer
	SyntaxErrorComplainer()
}

SyntaxErrorComplainer is used to represent a specific kind of BadRequestComplainer error. Specifically, it represents a syntax error in a data URL passed to the dataurl.Parse() func or the dataurl.MustParse() func.

Example usage is as follows:

parcel, err := dataurl.Parse("data:,Hello%20world!")
if nil != err {
	switch err.(type) {

	case dataurl.SyntaxErrorComplainer: // ← Here we are detecting if the error returned was due to a syntax error, in the data URL. Also note that it comes BEFORE the 'dataurl.BadRequestComplainer' case; THAT IS IMPORTANT!

		fmt.Printf("The data URL passed to dataurl.Parse() had a syntax error in it. The error message describing the syntax error is....\n%s\n", err.Error())
		return

	case dataurl.BadRequestComplainer:

		fmt.Printf("Something you did when you called dataurl.Parse() caused an error. The error message was....\n%s\n", err.Error())
		return

	case dataurl.InternalErrorComplainer:

		fmt.Printf("It's not your fault; it's my fault. Something bad happened internally when dataurl.Parse() was running. The error message was....\n%s\n", err.Error())
		return

	default:

		fmt.Printf("Some kind of unexpected error happend: %v", err)
		return
	}
}