GRequests

A Go "clone" of the great and famous Requests library

License

GRequests is licensed under the Apache License, Version 2.0. See LICENSE for the full license text

Features

Responses can be serialized into JSON and XML
Easy file uploads
Easy file downloads
Support for the following HTTP verbs GET, HEAD, POST, PUT, DELETE, PATCH, OPTIONS

Install

go get -u github.com/levigross/grequests

Usage

import "github.com/levigross/grequests"

Basic Examples

Basic GET request:

resp, err := grequests.Get("http://httpbin.org/get", nil)
// You can modify the request by passing an optional RequestOptions struct

if err != nil {
	log.Fatalln("Unable to make request: ", err)
}

fmt.Println(resp.String())
// {
//   "args": {},
//   "headers": {
//     "Accept": "*/*",
//     "Host": "httpbin.org",

If an error occurs all of the other properties and methods of a Response will be nil

Quirks

Request Quirks

When passing parameters to be added to a URL, if the URL has existing parameters that contradict with what has been passed within Params – Params will be the "source of authority" and overwrite the contradicting URL parameter.

Lets see how it works...

ro := &RequestOptions{
	Params: map[string]string{"Hello": "Goodbye"},
}
Get("http://httpbin.org/get?Hello=World", ro)
// The URL is now http://httpbin.org/get?Hello=Goodbye

Response Quirks

Order matters! This is because grequests.Response is implemented as an io.ReadCloser which proxies the http.Response.Body io.ReadCloser interface. It also includes an internal buffer for use in Response.String() and Response.Bytes().

Here are a list of methods that consume the http.Response.Body io.ReadCloser interface.

Response.JSON
Response.XML
Response.DownloadToFile
Response.Close
Response.Read

The following methods make use of an internal byte buffer

Response.String
Response.Bytes

In the code below, once the file is downloaded – the Response struct no longer has access to the request bytes

response := Get("http://some-wonderful-file.txt", nil)

if err := response.DownloadToFile("randomFile"); err != nil {
	log.Println("Unable to download file: ", err)
}

// At this point the .String and .Bytes method will return empty responses

response.Bytes() == nil // true
response.String() == "" // true

But if we were to call response.Bytes() or response.String() first, every operation will succeed until the internal buffer is cleared:

response := Get("http://some-wonderful-file.txt", nil)

// This call to .Bytes caches the request bytes in an internal byte buffer – which can be used again and again until it is cleared
response.Bytes() == `file-bytes`
response.String() == "file-string"

// This will work because it will use the internal byte buffer
if err := resp.DownloadToFile("randomFile"); err != nil {
	log.Println("Unable to download file: ", err)
}

// Now if we clear the internal buffer....
response.ClearInternalBuffer()

// At this point the .String and .Bytes method will return empty responses

response.Bytes() == nil // true
response.String() == "" // true

grequests

import "github.com/levigross/grequests"

Overview
Index
Examples

Overview

Package grequests implements a friendly API over Go's existing net/http library

Index

Variables
func BuildHTTPClient(ro RequestOptions) *http.Client
func EnsureTransporterFinalized(httpTransport *http.Transport)
func FileUploadFromDisk(fileName string) ([]FileUpload, error)
func FileUploadFromGlob(fileSystemGlob string) ([]FileUpload, error)
type FileUpload
type RequestOptions
type Response
type Session
type XMLCharDecoder

Package files

base.go file_upload.go request.go response.go session.go utils.go

Variables

var (
    // ErrRedirectLimitExceeded is the error returned when the request responded
    // with too many redirects
    ErrRedirectLimitExceeded = errors.New("grequests: Request exceeded redirect count")

    // RedirectLimit is a tunable variable that specifies how many times we can
    // redirect in response to a redirect. This is the global variable, if you
    // wish to set this on a request by request basis, set it within the
    // `RequestOptions` structure
    RedirectLimit = 30

    // SensitiveHTTPHeaders is a map of sensitive HTTP headers that a user
    // doesn't want passed on a redirect. This is the global variable, if you
    // wish to set this on a request by request basis, set it within the
    // `RequestOptions` structure
    SensitiveHTTPHeaders = map[string]struct{}{
        "Www-Authenticate":    {},
        "Authorization":       {},
        "Proxy-Authorization": {},
    }
)

func BuildHTTPClient

func BuildHTTPClient(ro RequestOptions) *http.Client

BuildHTTPClient is a function that will return a custom HTTP client based on the request options provided the check is in UseDefaultClient

func EnsureTransporterFinalized

func EnsureTransporterFinalized(httpTransport *http.Transport)

EnsureTransporterFinalized will ensure that when the HTTP client is GCed the runtime will close the idle connections (so that they won't leak) this function was adopted from Hashicorp's go-cleanhttp package

func FileUploadFromDisk

func FileUploadFromDisk(fileName string) ([]FileUpload, error)

FileUploadFromDisk allows you to create a FileUpload struct slice by just specifying a location on the disk

func FileUploadFromGlob

func FileUploadFromGlob(fileSystemGlob string) ([]FileUpload, error)

FileUploadFromGlob allows you to create a FileUpload struct slice by just specifying a glob location on the disk this function will gloss over all errors in the files and only upload the files that don't return errors from the glob

type FileUpload

type FileUpload struct {
    // Filename is the name of the file that you wish to upload. We use this to guess the mimetype as well as pass it onto the server
    FileName string

    // FileContents is happy as long as you pass it a io.ReadCloser (which most file use anyways)
    FileContents io.ReadCloser

    // FieldName is form field name
    FieldName string
}

FileUpload is a struct that is used to specify the file that a User wishes to upload.

type RequestOptions

type RequestOptions struct {

    // Data is a map of key values that will eventually convert into the
    // query string of a GET request or the body of a POST request.
    Data map[string]string

    // Params is a map of query strings that may be used within a GET request
    Params map[string]string

    // QueryStruct is a struct that encapsulates a set of URL query params
    // this paramter is mutually exclusive with `Params map[string]string` (they cannot be combined)
    // for more information please see https://godoc.org/github.com/google/go-querystring/query
    QueryStruct interface{}

    // Files is where you can include files to upload. The use of this data
    // structure is limited to POST requests
    Files []FileUpload

    // JSON can be used when you wish to send JSON within the request body
    JSON interface{}

    // XML can be used if you wish to send XML within the request body
    XML interface{}

    // Headers if you want to add custom HTTP headers to the request,
    // this is your friend
    Headers map[string]string

    // InsecureSkipVerify is a flag that specifies if we should validate the
    // server's TLS certificate. It should be noted that Go's TLS verify mechanism
    // doesn't validate if a certificate has been revoked
    InsecureSkipVerify bool

    // DisableCompression will disable gzip compression on requests
    DisableCompression bool

    // UserAgent allows you to set an arbitrary custom user agent
    UserAgent string

    // Host allows you to set an arbitrary custom host
    Host string

    // Auth allows you to specify a user name and password that you wish to
    // use when requesting the URL. It will use basic HTTP authentication
    // formatting the username and password in base64 the format is:
    // []string{username, password}
    Auth []string

    // IsAjax is a flag that can be set to make the request appear
    // to be generated by browser Javascript
    IsAjax bool

    // Cookies is an array of `http.Cookie` that allows you to attach
    // cookies to your request
    Cookies []*http.Cookie

    // UseCookieJar will create a custom HTTP client that will
    // process and store HTTP cookies when they are sent down
    UseCookieJar bool

    // Proxies is a map in the following format
    // *protocol* => proxy address e.g http => http://127.0.0.1:8080
    Proxies map[string]*url.URL

    // TLSHandshakeTimeout specifies the maximum amount of time waiting to
    // wait for a TLS handshake. Zero means no timeout.
    TLSHandshakeTimeout time.Duration

    // DialTimeout is the maximum amount of time a dial will wait for
    // a connect to complete.
    DialTimeout time.Duration

    // KeepAlive specifies the keep-alive period for an active
    // network connection. If zero, keep-alive are not enabled.
    DialKeepAlive time.Duration

    // RequestTimeout is the maximum amount of time a whole request(include dial / request / redirect)
    // will wait.
    RequestTimeout time.Duration

    // HTTPClient can be provided if you wish to supply a custom HTTP client
    // this is useful if you want to use an OAUTH client with your request.
    HTTPClient *http.Client

    // SensitiveHTTPHeaders is a map of sensitive HTTP headers that a user
    // doesn't want passed on a redirect.
    SensitiveHTTPHeaders map[string]struct{}

    // RedirectLimit is the acceptable amount of redirects that we should expect
    // before returning an error be default this is set to 30. You can change this
    // globally by modifying the `RedirectLimit` variable.
    RedirectLimit int

    // RequestBody allows you to put anything matching an `io.Reader` into the request
    // this option will take precedence over any other request option specified
    RequestBody io.Reader

    // CookieJar allows you to specify a special cookiejar to use with your request.
    // this option will take precedence over the `UseCookieJar` option above.
    CookieJar http.CookieJar

    // Context can be used to maintain state between requests https://golang.org/pkg/context/#Context
    Context context.Context
}

RequestOptions is the location that of where the data

type Response

type Response struct {

    // Ok is a boolean flag that validates that the server returned a 2xx code
    Ok bool

    // This is the Go error flag – if something went wrong within the request, this flag will be set.
    Error error

    // We want to abstract (at least at the moment) the Go http.Response object away. So we are going to make use of it
    // internal but not give the user access
    RawResponse *http.Response

    // StatusCode is the HTTP Status Code returned by the HTTP Response. Taken from resp.StatusCode
    StatusCode int

    // Header is a net/http/Header structure
    Header http.Header
    // contains filtered or unexported fields
}

Response is what is returned to a user when they fire off a request