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bitbucket.org/eventy-events/facebook

Package facebook

v1.8.1
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The highest tagged major version is .

Published: Mar 23, 2017 | License: MIT | Module: bitbucket.org/eventy-events/facebook

Overview

This is a Go library fully supports Facebook Graph API (both 1.0 and 2.x) with file upload, batch request, FQL and multi-FQL. It can be used in Google App Engine.

Library design is highly influenced by facebook official PHP/JS SDK. If you have experience with PHP/JS SDK, you may feel quite familiar with it.

Go to project home page to see samples. Link: https://github.com/huandu/facebook

This library doesn't implement any deprecated old RESTful API. And it won't.

Index

Constants

const (
	ERROR_CODE_UNKNOWN = -1 // unknown facebook graph api error code.

)

Variables

var (
	// Default facebook api version.
	// It can be any valid version string (e.g. "v2.3") or empty.
	//
	// See https://developers.facebook.com/docs/apps/versions for details.
	Version string

	// Set app level debug mode.
	// After setting DebugMode, all newly created session will use the mode
	// to communicate with graph API.
	//
	// See https://developers.facebook.com/docs/graph-api/using-graph-api/v2.3#debugging
	Debug DebugMode
)

func Data

func Data(filename string, source io.Reader) *binaryData

Creates new binary data holder.

func DataWithContentType

func DataWithContentType(filename string, source io.Reader, contentType string) *binaryData

Creates new binary data holder with arbitrary content type.

func File

func File(filename string) *binaryFile

Creates a binary file holder.

func FileAlias

func FileAlias(filename, path string) *binaryFile

Creates a binary file holder and specific a different path for reading.

func FileAliasWithContentType

func FileAliasWithContentType(filename, path, contentType string) *binaryFile

Creates a new binary file holder with arbitrary content type.

func SetHttpClient

func SetHttpClient(client HttpClient)

SetHttpClient updates the http client of default session.

type App

type App struct {
	// Facebook app id
	AppId string

	// Facebook app secret
	AppSecret string

	// Facebook app redirect URI in the app's configuration.
	RedirectUri string

	// Enable appsecret proof in every API call to facebook.
	// Facebook document: https://developers.facebook.com/docs/graph-api/securing-requests
	EnableAppsecretProof bool
}

Holds facebook application information.

func New

func New(appId, appSecret string) *App

Creates a new App and sets app id and secret.

func (*App) AppAccessToken

func (app *App) AppAccessToken() string

Gets application access token, useful for gathering public information about users and applications.

func (*App) ExchangeToken

func (app *App) ExchangeToken(accessToken string) (token string, expires int, err error)

Exchange a short lived access token to a long lived access token. Return new access token and its expires time.

func (*App) GetCode

func (app *App) GetCode(accessToken string) (code string, err error)

Get code from a long lived access token. Return the code retrieved from facebook.

func (*App) ParseCode

func (app *App) ParseCode(code string) (token string, err error)

ParseCode redeems code for a valid access token. It's a shorthand call to ParseCodeInfo(code, "").

In facebook PHP SDK, there is a CSRF state to avoid attack. That state is not checked in this library. Caller is responsible to store and check state if possible.

func (*App) ParseCodeInfo

func (app *App) ParseCodeInfo(code, machineId string) (token string, expires int, newMachineId string, err error)

ParseCodeInfo redeems code for access token and returns extra information. The machineId is optional.

See https://developers.facebook.com/docs/facebook-login/access-tokens#extending

func (*App) ParseSignedRequest

func (app *App) ParseSignedRequest(signedRequest string) (res Result, err error)

Parses signed request.

func (*App) Session

func (app *App) Session(accessToken string) *Session

Creates a session based on current App setting.

func (*App) SessionFromSignedRequest

func (app *App) SessionFromSignedRequest(signedRequest string) (session *Session, err error)

Creates a session from a signed request. If signed request contains a code, it will automatically use this code to exchange a valid access token.

type BatchResult

type BatchResult struct {
	StatusCode int         // HTTP status code.
	Header     http.Header // HTTP response headers.
	Body       string      // Raw HTTP response body string.
	Result     Result      // Facebook api result parsed from body.
}

Represents facebook batch API call result. See https://developers.facebook.com/docs/graph-api/making-multiple-requests/#multiple_methods.

type DebugInfo

type DebugInfo struct {
	Messages []DebugMessage // debug messages. it can be nil if there is no message.
	Header   http.Header    // all HTTP headers for this response.
	Proto    string         // HTTP protocol name for this response.

	// Facebook debug HTTP headers.
	FacebookApiVersion string // the actual graph API version provided by facebook-api-version HTTP header.
	FacebookDebug      string // the X-FB-Debug HTTP header.
	FacebookRev        string // the x-fb-rev HTTP header.
}

DebugInfo is the debug information returned by facebook when debug mode is enabled.

type DebugMessage

type DebugMessage struct {
	Type    string
	Message string
	Link    string
}

DebugMessage is one debug message in "__debug__" of graph API response.

type DebugMode

type DebugMode string

Graph API debug mode. See https://developers.facebook.com/docs/graph-api/using-graph-api/v2.3#graphapidebugmode

const (
	DEBUG_OFF DebugMode = "" // turn off debug.

	DEBUG_ALL     DebugMode = "all"
	DEBUG_INFO    DebugMode = "info"
	DEBUG_WARNING DebugMode = "warning"
)

Graph API debug mode values.

type Error

type Error struct {
	Message      string
	Type         string
	Code         int
	ErrorSubcode int // subcode for authentication related errors.
}

Facebook API error.

func (*Error) Error

func (e *Error) Error() string

Returns error string.

type HttpClient

type HttpClient interface {
	Do(req *http.Request) (resp *http.Response, err error)
	Get(url string) (resp *http.Response, err error)
	Post(url string, bodyType string, body io.Reader) (resp *http.Response, err error)
}

An interface to send http request. This interface is designed to be compatible with type `*http.Client`.

func DefaultHttpClient

func DefaultHttpClient() HttpClient

DefaultHttpClient returns the http client for default session.

type Method

type Method string

API HTTP method. Can be GET, POST or DELETE.

const (
	GET    Method = "GET"
	POST   Method = "POST"
	DELETE Method = "DELETE"
	PUT    Method = "PUT"
)

Facebook graph api methods.

type PagingResult

type PagingResult struct {
	// contains filtered or unexported fields
}

Represents facebook API call result with paging information.

func (*PagingResult) Data

func (pr *PagingResult) Data() []Result

Get current data.

func (*PagingResult) Decode

func (pr *PagingResult) Decode(v interface{}) (err error)

Decodes the current full result to a struct. See Result#Decode.

func (*PagingResult) HasNext

func (pr *PagingResult) HasNext() bool

Check whether there is next page.

func (*PagingResult) HasPrevious

func (pr *PagingResult) HasPrevious() bool

Check whether there is previous page.

func (*PagingResult) Next

func (pr *PagingResult) Next() (noMore bool, err error)

Read next page.

func (*PagingResult) Previous

func (pr *PagingResult) Previous() (noMore bool, err error)

Read previous page.

type Params

type Params map[string]interface{}

API params.

For general uses, just use Params as a ordinary map.

For advanced uses, use MakeParams to create Params from any struct.

func MakeParams

func MakeParams(data interface{}) (params Params)

Makes a new Params instance by given data. Data must be a struct or a map with string keys. MakeParams will change all struct field name to lower case name with underscore. e.g. "FooBar" will be changed to "foo_bar".

Returns nil if data cannot be used to make a Params instance.

func (Params) Encode

func (params Params) Encode(writer io.Writer) (mime string, err error)

Encodes params to query string. If map value is not a string, Encode uses json.Marshal() to convert value to string.

Encode will panic if Params contains values that cannot be marshalled to json string.

type Result

type Result map[string]interface{}

Facebook API call result.

func Api

func Api(path string, method Method, params Params) (Result, error)

Makes a facebook graph api call with default session.

Method can be GET, POST, DELETE or PUT.

Params represents query strings in this call. Keys and values in params will be encoded for URL automatically. So there is no need to encode keys or values in params manually. Params can be nil.

If you want to get

https://graph.facebook.com/huandu?fields=name,username

Api should be called as following

Api("/huandu", GET, Params{"fields": "name,username"})

or in a simplified way

Get("/huandu", Params{"fields": "name,username"})

Api is a wrapper of Session.Api(). It's designed for graph api that doesn't require app id, app secret and access token. It can be called in multiple goroutines.

If app id, app secret or access token is required in graph api, caller should create a new facebook session through App instance instead.

func Batch

func Batch(batchParams Params, params ...Params) ([]Result, error)

Makes a batch facebook graph api call with default session. Batch is designed for more advanced usage including uploading binary files.

An uploading files sample

// equivalent to following curl command (borrowed from facebook docs)
//     curl \
//         -F 'access_token=…' \
//         -F 'batch=[{"method":"POST","relative_url":"me/photos","body":"message=My cat photo","attached_files":"file1"},{"method":"POST","relative_url":"me/photos","body":"message=My dog photo","attached_files":"file2"},]' \
//         -F 'file1=@cat.gif' \
//         -F 'file2=@dog.jpg' \
//         https://graph.facebook.com
Batch(Params{
    "access_token": "the-access-token",
    "file1": File("cat.gif"),
    "file2": File("dog.jpg"),
}, Params{
    "method": "POST",
    "relative_url": "me/photos",
    "body": "message=My cat photo",
    "attached_files": "file1",
}, Params{
    "method": "POST",
    "relative_url": "me/photos",
    "body": "message=My dog photo",
    "attached_files": "file2",
})

Facebook document: https://developers.facebook.com/docs/graph-api/making-multiple-requests

func BatchApi

func BatchApi(accessToken string, params ...Params) ([]Result, error)

Makes a batch facebook graph api call with default session.

BatchApi supports most kinds of batch calls defines in facebook batch api document, except uploading binary data. Use Batch to do so.

Note: API response is stored in "body" field of a Result.

results, _ := BatchApi(accessToken, Params{...}, Params{...})

// Use first batch api response.
var res1 *BatchResult
var err error
res1, err = results[0].Batch()

if err != nil {
    // this is not a valid batch api response.
}

// Use BatchResult#Result to get response body content as Result.
res := res1.Result

Facebook document: https://developers.facebook.com/docs/graph-api/making-multiple-requests

func Delete

func Delete(path string, params Params) (Result, error)

Delete is a short hand of Api(path, DELETE, params).

func FQL

func FQL(query string) ([]Result, error)

[Deprecated] Makes a FQL query with default session. Returns a slice of Result. If there is no query result, the result is nil.

FQL can only make query without "access_token". For query requiring "access_token", create Session and call its FQL method.

Facebook document: https://developers.facebook.com/docs/technical-guides/fql#query

func Get

func Get(path string, params Params) (Result, error)

Get is a short hand of Api(path, GET, params).

func MakeResult

func MakeResult(jsonBytes []byte) (Result, error)

MakeResult makes a Result from facebook Graph API response.

func MultiFQL

func MultiFQL(queries Params) (Result, error)

[Deprecated] Makes a multi FQL query with default session. Returns a parsed Result. The key is the multi query key, and the value is the query result.

MultiFQL can only make query without "access_token". For query requiring "access_token", create Session and call its MultiFQL method.

See Session.MultiFQL document for samples.

Facebook document: https://developers.facebook.com/docs/technical-guides/fql#multi

func Post

func Post(path string, params Params) (Result, error)

Post is a short hand of Api(path, POST, params).

func Put

func Put(path string, params Params) (Result, error)

Put is a short hand of Api(path, PUT, params).

func Request

func Request(request *http.Request) (Result, error)

Makes an arbitrary HTTP request with default session. It expects server responses a facebook Graph API response.

request, _ := http.NewRequest("https://graph.facebook.com/538744468", "GET", nil)
res, err := Request(request)
fmt.Println(res["gender"])  // get "male"

func (Result) Batch

func (res Result) Batch() (*BatchResult, error)

Batch creates a BatchResult for this result and returns error if the Result is not a batch api response.

See BatchApi document for a sample usage.

func (Result) DebugInfo

func (res Result) DebugInfo() *DebugInfo

DebugInfo creates a DebugInfo for this result if this result has "__debug__" key.

func (Result) Decode

func (res Result) Decode(v interface{}) (err error)

Decode decodes full result to a struct. It only decodes fields defined in the struct.

As all facebook response fields are lower case strings, Decode will convert all camel-case field names to lower case string. e.g. field name "FooBar" will be converted to "foo_bar". The side effect is that if a struct has 2 fields with only capital differences, decoder will map these fields to a same result value.

If a field is missing in the result, Decode keeps it unchanged by default.

Decode can read struct field tag value to change default behavior.

Examples:

type Foo struct {
    // "id" must exist in response. note the leading comma.
    Id string `facebook:",required"`

    // use "name" as field name in response.
    TheName string `facebook:"name"`
}

To change default behavior, set a struct tag `facebook:",required"` to fields should not be missing.

Returns error if v is not a struct or any required v field name absents in res.

func (Result) DecodeField

func (res Result) DecodeField(field string, v interface{}) error

DecodeField decodes a field of result to any type, including struct. Field name format is defined in Result.Get().

More details about decoding struct see Result.Decode().

func (Result) Err

func (res Result) Err() error

Err returns an error if Result is a Graph API error.

The returned error can be converted to Error by type assertion.

err := res.Err()
if err != nil {
    if e, ok := err.(*Error); ok {
        // read more details in e.Message, e.Code and e.Type
    }
}

For more information about Graph API Errors, see https://developers.facebook.com/docs/reference/api/errors/

func (Result) Get

func (res Result) Get(field string) interface{}

Get gets a field from Result.

Field can be a dot separated string. If field name is "a.b.c", it will try to return value of res["a"]["b"]["c"].

To access array items, use index value in field. For instance, field "a.0.c" means to read res["a"][0]["c"].

It doesn't work with Result which has a key contains dot. Use GetField in this case.

Returns nil if field doesn't exist.

func (Result) GetField

func (res Result) GetField(fields ...string) interface{}

GetField gets a field from Result.

Arguments are treated as keys to access value in Result. If arguments are "a","b","c", it will try to return value of res["a"]["b"]["c"].

To access array items, use index value as a string. For instance, args of "a", "0", "c" means to read res["a"][0]["c"].

Returns nil if field doesn't exist.

func (Result) Paging

func (res Result) Paging(session *Session) (*PagingResult, error)

Paging creates a PagingResult for this Result and returns error if the Result cannot be used for paging.

Facebook uses following JSON structure to response paging information. If "data" doesn't present in Result, Paging will return error.

{
    "data": [...],
    "paging": {
        "previous": "https://graph.facebook.com/...",
        "next": "https://graph.facebook.com/..."
    }
}

type Session

type Session struct {
	HttpClient HttpClient
	Version    string // facebook versioning.
	// contains filtered or unexported fields
}

Holds a facebook session with an access token. Session should be created by App.Session or App.SessionFromSignedRequest.

func (*Session) AccessToken

func (session *Session) AccessToken() string

Gets current access token.

func (*Session) Api

func (session *Session) Api(path string, method Method, params Params) (Result, error)

Makes a facebook graph api call.

If session access token is set, "access_token" in params will be set to the token value.

Returns facebook graph api call result. If facebook returns error in response, returns error details in res and set err.

func (*Session) App

func (session *Session) App() *App

Gets associated App.

func (*Session) AppsecretProof

func (session *Session) AppsecretProof() string

Check appsecret proof is enabled or not.

func (*Session) Batch

func (session *Session) Batch(batchParams Params, params ...Params) ([]Result, error)

Makes a batch facebook graph api call. Batch is designed for more advanced usage including uploading binary files.

If session access token is set, "access_token" in batchParams will be set to the token value.

Facebook document: https://developers.facebook.com/docs/graph-api/making-multiple-requests

func (*Session) BatchApi

func (session *Session) BatchApi(params ...Params) ([]Result, error)

Makes a batch call. Each params represent a single facebook graph api call.

BatchApi supports most kinds of batch calls defines in facebook batch api document, except uploading binary data. Use Batch to upload binary data.

If session access token is set, the token will be used in batch api call.

Returns an array of batch call result on success.

Facebook document: https://developers.facebook.com/docs/graph-api/making-multiple-requests

func (*Session) Debug

func (session *Session) Debug() DebugMode

Debug returns current debug mode.

func (*Session) Delete

func (session *Session) Delete(path string, params Params) (Result, error)

Delete is a short hand of Api(path, DELETE, params).

func (*Session) EnableAppsecretProof

func (session *Session) EnableAppsecretProof(enabled bool) error

Enable or disable appsecret proof status. Returns error if there is no App associasted with this Session.

func (*Session) FQL

func (session *Session) FQL(query string) ([]Result, error)

Makes a FQL query. Returns a slice of Result. If there is no query result, the result is nil.

Facebook document: https://developers.facebook.com/docs/technical-guides/fql#query

func (*Session) Get

func (session *Session) Get(path string, params Params) (Result, error)

Get is a short hand of Api(path, GET, params).

func (*Session) Inspect

func (session *Session) Inspect() (result Result, err error)

Inspect Session access token. Returns JSON array containing data about the inspected token. See https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow/v2.2#checktoken

func (*Session) MultiFQL

func (session *Session) MultiFQL(queries Params) (Result, error)

Makes a multi FQL query. Returns a parsed Result. The key is the multi query key, and the value is the query result.

Here is a multi-query sample.

res, _ := session.MultiFQL(Params{
    "query1": "SELECT name FROM user WHERE uid = me()",
    "query2": "SELECT uid1, uid2 FROM friend WHERE uid1 = me()",
})

// Get query results from response.
var query1, query2 []Result
res.DecodeField("query1", &query1)
res.DecodeField("query2", &query2)

Facebook document: https://developers.facebook.com/docs/technical-guides/fql#multi

func (*Session) Post

func (session *Session) Post(path string, params Params) (Result, error)

Post is a short hand of Api(path, POST, params).

func (*Session) Put

func (session *Session) Put(path string, params Params) (Result, error)

Put is a short hand of Api(path, PUT, params).

func (*Session) Request

func (session *Session) Request(request *http.Request) (res Result, err error)

Makes an arbitrary HTTP request. It expects server responses a facebook Graph API response.

request, _ := http.NewRequest("https://graph.facebook.com/538744468", "GET", nil)
res, err := session.Request(request)
fmt.Println(res["gender"])  // get "male"

func (*Session) SetAccessToken

func (session *Session) SetAccessToken(token string)

Sets a new access token.

func (*Session) SetDebug

func (session *Session) SetDebug(debug DebugMode) DebugMode

SetDebug updates per session debug mode and returns old mode. If per session debug mode is DEBUG_OFF, session will use global Debug mode.

func (*Session) User

func (session *Session) User() (id string, err error)

Gets current user id from access token.

Returns error if access token is not set or invalid.

It's a standard way to validate a facebook access token.

func (*Session) Validate

func (session *Session) Validate() (err error)

Validates Session access token. Returns nil if access token is valid.

Package Files

Documentation was rendered with GOOS=linux and GOARCH=amd64.

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