base642img

README

imgbase64

Convert an image to its base64 equivalent. API Documentation on go.pkgdoc.org.

Features

• Fetch an image from an external server and convert to base64
• Use an image on your local machine to convert to base64
• Share a bytes.Buffer to the package to detect the mime type and convert the image to base64
• Ability to set a failover image if desired image throws an error or does not exist.
• Automatically converts urls with " " to %20. Note: If your target domain uses +, _, etc. for space indicators it is your responsibility to modify the url accordingly.
• Correctly sets the base64 encoding type to the media type of the image. Example: data:image/jpeg;base64
• Returned image is ready to be used

Installation

go get github.com/polds/imgbase64

Usage

imgbase64.SetDefaultImage("http://yourdomain.com/defaultimage.png") // Optional - If FromRemote fails it will return " "

// Fetch the image from a remote server
img := imgbase64.FromRemote("http://somedomain.com/animage.jpg")

// Use an image local to machine
img := imgbase64.FromLocal("test.png")

// Pass an image buffer to package
img := imgbase64.FromBuffer(b)

Notes

• Please make sure your Default Image is a working image url. If your Default Image fails to load the package will panic(). This was deliberate.
• FromLocal has several instances where it might panic(), these are deliberate.

Todo

• Better error detection. Websites with custom 404 pages will sometimes "succeed" as being images and the package will base64 the html content of that page.
• Ability to use local images to convert to base64
• Cache the Default Image only once during the lifetime of the application. Presently every failed image is repulled.
• Deprecate NewImage
• Allow use of DefaultImage with FromBuffer and FromLocal

Change Log

October 24, 2013

• ADD: FromLocal - Allows you to base64 encode local images
• ADD: FromBuffer - Allows you to base64 encode from a byte.Buffer
• CHANGE: Rename function NewImage to FromRemote, please update accordingly. Will remove NewImage in future commits.
• ADD: Examples

This is my first package in Go. Suggestions or comments please tweet @Peter_Olds

Documentation

Index

• func DefaultImage() string
• func FromBuffer(buf bytes.Buffer, hasHeader bool) string
• func FromLocal(fname string) (string, error)
• func FromRemote(url string, hasHeader bool) string
• func New(ctx activity.InitContext) (activity.Activity, error)
• func NewImage(url string) string
• func SetDefaultImage(img string)
• func ToBuffer(buf []byte) ([]byte, error)
• func ToLocal(buf []byte, fname string) ([]byte, error)
• type Activity
  • func (a *Activity) Eval(ctx activity.Context) (done bool, err error)
  • func (a *Activity) Metadata() *activity.Metadata
• type Input
  • func (r *Input) FromMap(values map[string]interface{}) error
  • func (r *Input) ToMap() map[string]interface{}
• type Output
  • func (o *Output) FromMap(values map[string]interface{}) error
  • func (o *Output) ToMap() map[string]interface{}

Functions

func DefaultImage

func DefaultImage() string

DefaultImage :Get Default Image

func FromBuffer

func FromBuffer(buf bytes.Buffer, hasHeader bool) string

FromBuffer accepts a buffer and returns a base64 encoded string.

func FromLocal

func FromLocal(fname string) (string, error)

FromLocal reads a local file and returns the base64 encoded version.

func FromRemote

func FromRemote(url string, hasHeader bool) string

FromRemote is a better named function that presently calls NewImage which will be deprecated. Function accepts an RFC compliant URL and returns a base64 encoded result.

func New

func New(ctx activity.InitContext) (activity.Activity, error)

New optional factory method, should be used if one activity instance per configuration is desired

func NewImage

func NewImage(url string) string

NewImage : Begin a NewImage to fetch TODO: Deprecate NewImage

func SetDefaultImage

func SetDefaultImage(img string)

SetDefaultImage :Set Default Image

func ToBuffer

func ToBuffer(buf []byte) ([]byte, error)

ToBuffer accepts a base64 encoded string

and returns a file buffer can save to image file.

func ToLocal

func ToLocal(buf []byte, fname string) ([]byte, error)

ToLocal accepts a base64 encoded stringreads and save to local file then return save path.

Types

type Activity

type Activity struct {
}

Activity is an sample Activity that can be used as a base to create a custom activity

func (*Activity) Eval

func (a *Activity) Eval(ctx activity.Context) (done bool, err error)

Eval implements api.Activity.Eval - Logs the Message

func (*Activity) Metadata

func (a *Activity) Metadata() *activity.Metadata

Metadata returns the activity's metadata

type Input

type Input struct {
	AnInput string `md:"anInput,required"`
	AnPath  string `md:"anPath"`
}

func (*Input) FromMap

func (r *Input) FromMap(values map[string]interface{}) error

func (*Input) ToMap

func (r *Input) ToMap() map[string]interface{}

type Output

type Output struct {
	AnOutput []byte `md:"anOutput"`
}

func (*Output) FromMap

func (o *Output) FromMap(values map[string]interface{}) error

func (*Output) ToMap

func (o *Output) ToMap() map[string]interface{}