经典 ASP 和 Facebook Graph API

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引言

在上一篇文章中，我提供了一组实用函数，用于通过 Facebook for Websites API 将您的网站连接到 Facebook。本文在前一篇应用的基础上进行改进，并添加了一些示例，说明如何利用 Facebook 的 Graph API 提供更深入的 Facebook 交互。

背景

本文将基于上一篇文章中已重构为类对象的相同代码。

什么是 Graph API？

Graph API 是 Facebook 基于RESTful 接口实现大多数 UI 功能自动化的方式。

Graph API 向 Facebook 发送请求，URL 类似于：http://graph.facebook.com/ID。ID 是您正在处理的 Facebook 对象的 ID。Facebook 中的每个对象都根据 REST 的要求具有 ID。您可以在此处找到完整的文档：http://developers.facebook.com/docs/reference/api/。

使用代码

在使用代码之前，您必须创建一个 Facebook 应用程序并拥有应用程序 ID 和密钥。有关详细信息，请参见第一篇文章。

在本文中，我将提供处理 Facebook 数据的基本模式。代码将实现一种一致的方式来返回 Facebook 数据，以便当您访问 user.hometown（例如）时，它将始终返回一个值或空值。如果 Facebook 未返回数据，也不会产生错误。新设计中的每个函数都包含有助于验证函数是否正常工作的测试页面。

重构旧代码

让我们回顾一下当前代码与上一篇文章的不同之处。主要的变化是，除了少数几个函数之外，所有函数都封装在一个名为 fb_utility 的类库中。下面的代码块显示了 fb_utility 的类结构。

''************************************************************
'' A summary of the fb_utility class as found in fb_app.asp
''************************************************************
class fb_utility
    dim dictKey 
    dim dictItem

    '' Initialize the fb_utility class
    sub Class_Initialize()
        '' Initialize KSort values
        dictKey  = 1
        dictItem = 2
    end sub

    '' get the contents of a web page, include 
    '' validation that the user is logged in
    public function get_page_contents(strURL)
    end function 
    

    '' Some Facebook API functions require a post
    '' this function handles the post request
    public function post_page(strURL, strData)
    end function 
    
    '' Generate a GUID
    public Function NewID()
    End Function        

    '' KSort is not required for the new oAuth
    '' however you might find it useful
    public function ksort(byref objDict )
        SortDictionary objDict, dictKey 
    end function
    
    '' Sort dictionary is called by the ksort function
    Function SortDictionary(byref objDict, intSort)
    End Function    
    
    '' gets the access token from the return 
    '' authentication request made to Facebook
    public function parse_access_token( str )
    end function

    '' Parses the expires value from the return data 
    '' provided after an oAuth request to Facebook
    '' I have yet to figure out how to make use of this
    public function parse_expires( str )
    end function
    
end class

这个实用工具类被 Graph API 和初始授权函数中的几乎所有其他类和函数重用。

基本请求模式

在大多数情况下，每个 Graph API 请求都会执行一些基本操作：调用 fb_utility.get_page_contents，它返回一个 JSON 字符串，然后将该字符串转换为 JSON 对象以供引用。Facebook 返回的数据存在一个问题，即如果某个值为空或 null，则不会返回该属性。例如：您请求的用户可能没有 hometown 信息，因此 Facebook 返回的 JSON 字符串将不包含 hometown 值。当 JSON 字符串转换为对象时，它将没有 hometown 属性。结果，尝试访问 user.hometown 将触发 VBScript 错误。我称之为“稀疏数据问题”。

为了解决稀疏数据问题，我在每个类中都包含了一个代码块，该代码块将 JSON 映射到 VBScript 类，从而为每个数据对象提供一个可靠的接口。

下面您将找到一个用 VBScript 类实现的 Facebook 数据类型对象的模式。调用 Load 并传递 Facebook 对象 ID 将获取 JSON 字符串，调用 load_from_json_object 将执行映射。

'' Copy and paste the template below for each new Facebook DTO class

'' A Facebook DTO
class fb_DTO

    '' **
    '' ** Declare Variables
    '' **
    
    '' Default Variables for properties 
    dim fbu '' Facebook utility object
    dim m_token ''
    dim m_json_str ''
    dim m_graph_url ''
    
    '' Default Internal Variables
    
    '' Object Type Specific Variables
    
    '' **   
    '' ** property exposure
    '' **

    
    '' Default Properties
    public property get graph_url()
        graph_url = m_graph_url
    end property
    
    public property get json_string()
        json_string = m_json_str
    end property
    
    public property get token()
        token = m_token
    end property
    public property let token(value)
        m_token = value
    end property
    
    
    '' Object Type property exposure
    
    '' initialization
    sub Class_Initialize
        set fbu = new fb_utility
    end sub
    
    '' termination
    sub Class_Terminate
        set fbu = nothing
   end sub

    '' **
    '' Implementation
    '' **
    
    '' Load object by id
    public sub Load(ID)
        dim obj
        
        m_graph_url = "https://graph.facebook.com/" & id & _
                      "?access_token=" & m_token 
        m_json_str = fbu.get_page_contents( m_graph_url )
        set obj = JSON.parse( m_json_str )
        load_from_json_object obj
    end sub
    
    public sub load_from_json_object( fb_obj )
    
        on error resume next
        '' map your properties here
        
        on error goto 0
        err.clear
    end sub
    
end class

真实世界示例 - Facebook 用户对象

接下来的代码块基于模式示例，并实现了一个 Facebook 用户对象。

''**************************************************************************
'' Copyright 2012 Larry Boeldt 
'' Class: facebook_user  V1.0    2012-01-26
'' Author: Larry Boeldt - lboeldt@scs-inc.net; larry@boeldt.net
''
'' Description:
''   Facebook user object
''
''**************************************************************************
class facebook_user
    dim m_id '' The user's Facebook ID
    dim m_name '' The user's full name
    dim m_first_name '' The user's first name
    dim m_middle_name '' The user's middle name
    dim m_last_name '' The user's last name
    dim m_gender '' The user's gender: female or male
    dim m_locale '' The user's locale
    dim m_languages '' The user's languages
    dim m_link '' The URL of the profile for the user on Facebook
    dim m_username '' The user's Facebook username
    dim m_third_party_id '' An anonymous, but unique identifier for the user;
                         '' only returned if specifically requested via the fields URL parameter
    dim m_timezone '' The user's timezone offset from UTC
    dim m_updated_time '' The last time the user's profile was updated;
                       '' changes to the languages, link, timezone, verified,
                       '' interested_in, favorite_athletes, favorite_teams,
                       '' and video_upload_limits are not not reflected in this value
    dim m_verified '' The user's account verification status, either true or false (see below)
    dim m_bio '' The user's biography
    dim m_birthday '' The user's birthday
    dim m_education '' A list of the user's education history
    dim m_email '' The proxied or contact email address granted by the user
    dim m_hometown '' The user's hometown
    dim m_interested_in '' The genders the user is interested in
    dim m_location '' The user's current city
    dim m_political '' The user's political view
    dim m_favorite_athletes '' The user's favorite athletes; this field
                            '' is deprecated and will be removed in the near future
    dim m_favorite_teams '' The user's favorite teams; this field
                '' is deprecated and will be removed in the near future
    dim m_quotes '' The user's favorite quotes
    dim m_relationship_status '' The user's relationship status: Single,
                  '' In a relationship, Engaged, Married, It's complicated,
                  '' In an open relationship, Widowed, Separated, Divorced,
                  '' In a civil union, In a domestic partnership
    dim m_religion '' The user's religion
    dim m_significant_other '' The user's significant other
    dim m_video_upload_limits '' The size of the video file and the length
              '' of the video that a user can upload; only returned
              '' if specifically requested via the fields URL parameter
    dim m_website '' The URL of the user's personal website
    dim m_token ''
    dim m_json_str ''
    dim m_graph_url ''
    dim fbu '' Facebook utility object
    
    sub Class_Initialize()
        m_id = ""
        m_name = ""
        m_first_name = ""
        m_middle_name = ""
        m_last_name = ""
        m_gender = ""
        m_locale = ""
        m_languages = ""
        m_link = ""
        m_username = ""
        m_third_party_id = ""
        m_timezone = ""
        m_updated_time = ""
        m_verified = ""
        m_bio = ""
        m_birthday = ""
        m_education = ""
        m_email = ""
        m_hometown = ""
        m_interested_in = ""
        m_location = ""
        m_political = ""
        m_quotes = ""
        m_relationship_status = ""
        m_religion = ""
        m_significant_other = ""
        m_video_upload_limits = ""
        m_website = ""
        
        set fbu = new fb_utility
    end sub

    public property get graph_url()
        graph_url = m_graph_url
    end property
    
    public property get json_string()
        json_string = m_json_str
    end property
    
    public property get token()
        token = m_token
    end property
    public property let token(value)
        m_token = value
    end property
    
    public property get id()
        id = m_id
    end property
    public property let id(value) 
        m_id = value 
    end property

    public property get name()
        name = m_name
    end property
    public property let name(value) 
        m_name = value 
    end property

    public property get first_name()
        first_name = m_first_name
    end property
    public property let first_name(value) 
        m_first_name = value 
    end property

    public property get middle_name()
        middle_name = m_middle_name
    end property
    public property let middle_name(value) 
        m_middle_name = value 
    end property

    public property get last_name()
        last_name = m_last_name
    end property
    public property let last_name(value) 
        m_last_name = value 
    end property

    public property get gender()
        gender = m_gender
    end property
    public property let gender(value) 
        m_gender = value 
    end property

    public property get locale()
        locale = m_locale
    end property
    public property let locale(value) 
        m_locale = value 
    end property

    public property get languages()
        languages = m_languages
    end property
    public property let languages(value) 
        m_languages = value 
    end property

    public property get link()
        link = m_link
    end property
    public property let link(value) 
        m_link = value 
    end property

    public property get username()
        username = m_username
    end property
    public property let username(value) 
        m_username = value 
    end property

    public property get third_party_id()
        third_party_id = m_third_party_id
    end property
    public property let third_party_id(value) 
        m_third_party_id = value 
    end property

    public property get timezone()
        timezone = m_timezone
    end property
    public property let timezone(value) 
        m_timezone = value 
    end property

    public property get updated_time()
        updated_time = m_updated_time
    end property
    public property let updated_time(value) 
        m_updated_time = value 
    end property

    public property get verified()
        verified = m_verified
    end property
    public property let verified(value) 
        m_verified = value 
    end property

    public property get bio()
        bio = m_bio
    end property
    public property let bio(value) 
        m_bio = value 
    end property

    public property get birthday()
        birthday = m_birthday
    end property
    public property let birthday(value) 
        m_birthday = value 
    end property

    public property get education()
        education = m_education
    end property
    public property let education(value) 
        m_education = value 
    end property

    public property get email()
        email = m_email
    end property
    public property let email(value) 
        m_email = value 
    end property

    public property get hometown()
        hometown = m_hometown
    end property
    public property let hometown(value) 
        m_hometown = value 
    end property

    public property get interested_in()
        interested_in = m_interested_in
    end property
    public property let interested_in(value) 
        m_interested_in = value 
    end property

    public property get location()
        location = m_location
    end property
    public property let location(value) 
        m_location = value 
    end property

    public property get political()
        political = m_political
    end property
    public property let political(value) 
        m_political = value 
    end property

    public property get quotes()
        quotes = m_quotes
    end property
    public property let quotes(value) 
        m_quotes = value 
    end property

    public property get relationship_status()
        relationship_status = m_relationship_status
    end property
    public property let relationship_status(value) 
        m_relationship_status = value 
    end property

    public property get religion()
        religion = m_religion
    end property
    public property let religion(value) 
        m_religion = value 
    end property

    public property get significant_other()
        significant_other = m_significant_other
    end property
    public property let significant_other(value) 
        m_significant_other = value 
    end property

    public property get video_upload_limits()
        video_upload_limits = m_video_upload_limits
    end property
    public property let video_upload_limits(value) 
        m_video_upload_limits = value 
    end property

    public property get website()
        website = m_website
    end property
    public property let website(value) 
        m_website = value 
    end property

    public sub LoadMe()
        dim strFields
        dim obj
        
        m_graph_url = "https://graph.facebook.com/me?access_token=" & _
            m_token 
        
        m_json_str = fbu.get_page_contents( m_graph_url )
        
        set obj = JSON.parse( m_json_str )
        
        load_from_json_user obj
        
    end sub

    public sub Load(ID)
        dim strFields
        dim obj
        
        m_graph_url = "https://graph.facebook.com/" & _
                      ID & "?access_token=" & _
                      m_token 
        
        m_json_str = fbu.get_page_contents( m_graph_url )
        
        set obj = JSON.parse( m_json_str )
        
        load_from_json_user obj
        
    end sub

    ''**************************************************************************
    '' Copyright 2012 Larry Boeldt 
    '' Function: load_from_json_user  V1.0    2012-01-26
    '' Author: Larry Boeldt - lboeldt@scs-inc.net; larry@boeldt.net
    '' Parameter(s):
    ''   fb_obj - The facebook object as returned from JSON.parse
    ''
    '' Description:
    ''   This function attempts to safely assign all user parameters from a 
    '' fasebook object so that you can consistently address the properties in 
    '' your code without concern about errors resulting from properties that
    '' are missing in the return json object
    ''**************************************************************************
    public sub load_from_json_user(fb_obj)
        on error resume next
        m_id = fb_obj.id
        m_name = fb_obj.name
        m_first_name = fb_obj.first_name
        m_middle_name = fb_obj.middle_name
        m_last_name = fb_obj.last_name
        m_gender = fb_obj.gender
        m_locale = fb_obj.locale
        m_languages = fb_obj.languages
        m_link = fb_obj.link
        m_username = fb_obj.username
        m_third_party_id = fb_obj.third_party_id
        m_timezone = fb_obj.timezone
        m_updated_time = fb_obj.updated_time
        m_verified = fb_obj.verified
        m_bio = fb_obj.bio
        m_birthday = fb_obj.birthday
        m_education = fb_obj.education
        m_email = fb_obj.email
        m_hometown = fb_obj.hometown.name
        m_interested_in = fb_obj.interested_in
        m_location = fb_obj.location.name
        m_political = fb_obj.political
        m_quotes = fb_obj.quotes
        m_relationship_status = fb_obj.relationship_status
        m_religion = fb_obj.religion
        m_significant_other = fb_obj.significant_other
        m_video_upload_limits = fb_obj.video_upload_limits
        m_website = fb_obj.website
        on error goto 0
        err.clear
    end sub
    
end class

使用 fb_graph_api 对象将它们整合在一起

为了保持使用此库的代码整洁，fb_graph_api 类实现了一个返回现成对象的函数。

当前库中有哪些内容？

截至本文撰写时，我提供了我正在处理的所有内容，但只有一些函数已准备好供您使用。其他示例处于 alpha 模式；风险自负。以下是可用的对象和相关的 graph_api “快捷方式”。

Facebook 对象名称	类名	Graph API 函数	测试页面
用户	fb_user	get_user	user_test.asp
Friends (用户对象列表)	fb_friends	get_friends	friends_test.asp
Friend	fb_user	get_friend	friend_test.asp
Album (相册)	fb_album	get_album	album_test.asp
Photo	fb_photo	get_photo	album_test.asp
注释	fb_comment	无，由其他对象调用。	none
例如	fb_like	无，由其他对象调用。注意：这是一个点赞对象，而不是点赞方法。我还没有实现那个。	none

Graph API 方法

目前仅实现了 post_to_wall 方法。

墙面帖子（post to wall）的测试页面是 post_wall_test.asp。目前只能发布到当前登录用户的墙面。

发布到墙面（post to wall）需要以下参数

参数名称	描述
Message	您想在墙面上显示的消息
图片	要与墙面帖子一起显示的图片的 URL
链接	作为链接目标的 URL
名称	要在链接上显示的名称
标题	链接的标题
描述	更长的文本，描述链接

关注点

DTO 类可以存储在会话（session）中，因为它们只使用 VBScript 变量，并且没有任何（如 scripting.dictionary）会引发线程模型问题的对象。

结论

虽然这里的示例不支持完整的 Graph API，但我认为您可以参考这里的示例来处理任何其他 API 数据。如果您实现了另一个模块，请在此处发布，我一定会将其包含在新版本中。我将在未来一年中每三个月发布一个新版本。您的反馈、建议和投票始终受到赞赏。

历史

• 发布版本 1。