本篇文章讲解XMPP中的电子名片和头像模块，只讲理论相关知识，不讲实践。本专题后续会有专门讲解如何使用电子名片和头像模块。
在Extensions中有XEP-0054扩展，提供了一种可以通过XMPP发送电子名片的机制。
vCard，也叫Versitcard，vCard的常用文件扩展名是.vcf。在XMPP中通过XMPPvCardTemp和XMPPvCardCoreDataStorage两个类来实现。 vCard是电子名片的文件格式标准，一般附加在电子邮件之后，但也可以用于其它场合，比如在因特网上相互交换。
Extensions扩展里的功能都是独立的，如果需要使用到相关功能，是需要自己手动添加的。当我们需要电子名片功能时，我们需要将电子名片扩展功能添加到XMPPStream中，才能使用。
首先，我们得引入电子名片扩展功能头文件：
// 电子名片相关模块头文件引入 #import "XMPPvCardTempModule.h" #import "XMPPvCardTemp.h" #import "XMPPvCardCoreDataStorage.h"
其中，三个类分别对应这样的功能：
XMPPvCardTemp 代表电子名片
XMPPvCardCoreDataStorage 代表电子名片在core data存储
XMPPvCardTempModule 用于提供电子名片增、删、改、查操作
XMPPvCardTemp就相当于电子名片类了，它是继承于NSXMLElement的。这个类提供了很多的属性，每个属性代表什么意思呢？电子名片上应该有什么，就会有哪些属性。看注释吧：
@interface XMPPvCardTemp : XMPPvCardTempBase // 出生日期 @property (nonatomic, strong) NSDate *bday; // 照片 @property (nonatomic, strong) NSData *photo; // 昵称 @property (nonatomic, strong) NSString *nickname; // full name @property (nonatomic, strong) NSString *formattedName; @property (nonatomic, strong) NSString *familyName; @property (nonatomic, strong) NSString *givenName; @property (nonatomic, strong) NSString *middleName; @property (nonatomic, strong) NSString *prefix; @property (nonatomic, strong) NSString *suffix; // 地址数组 @property (nonatomic, strong) NSArray *addresses; // Represents the actual text that should be put on the mailing label when delivering a physical package to the person/object associated with the vCard (related to the ADR property). @property (nonatomic, strong) NSArray *labels; @property (nonatomic, strong) NSArray *telecomsAddresses; @property (nonatomic, strong) NSArray *emailAddresses; @property (nonatomic, strong) XMPPJID *jid; // 邮件 @property (nonatomic, strong) NSString *mailer; // 时区 @property (nonatomic, strong) NSTimeZone *timeZone; // 地埋位置 @property (nonatomic, strong) CLLocation *location; // 职位 @property (nonatomic, strong) NSString *title; // 角色。标准说明：The role, occupation, or business // category of the vCard object within an organization. @property (nonatomic, strong) NSString *role; // logo @property (nonatomic, strong) NSData *logo; // 标准定义：Information about another person who will act // on behalf of the vCard object. Typically this would // be an area administrator, assistant, or secretary // for the individual. Can be either a URL or an embedded vCard. @property (nonatomic, strong) XMPPvCardTemp *agent; // 组织 @property (nonatomic, strong) NSString *orgName; /* * ORGUNITs can only be set if there is already an ORGNAME. Otherwise, changes are ignored. */ // 部门信息 @property (nonatomic, strong) NSArray *orgUnits; // A list of "tags" that can be used to describe the object represented by this vCard. // 也就是分类标签 @property (nonatomic, strong) NSArray *categories; // 电话 @property (nonatomic, strong) NSString *note; @property (nonatomic, strong) NSString *prodid; @property (nonatomic, strong) NSDate *revision; @property (nonatomic, strong) NSString *sortString; @property (nonatomic, strong) NSString *phoneticSound; @property (nonatomic, strong) NSData *sound; @property (nonatomic, strong) NSString *uid; // 个人网站URL @property (nonatomic, strong) NSString *url; // 电子名片版本 @property (nonatomic, strong) NSString *version; @property (nonatomic, strong) NSString *desc; @property (nonatomic, assign) XMPPvCardTempClass privacyClass; @property (nonatomic, strong) NSData *key; @property (nonatomic, strong) NSString *keyType; + (XMPPvCardTemp *)vCardTempFromElement:(NSXMLElement *)element; + (XMPPvCardTemp *)vCardTemp; + (XMPPvCardTemp *)vCardTempSubElementFromIQ:(XMPPIQ *)iq; + (XMPPvCardTemp *)vCardTempCopyFromIQ:(XMPPIQ *)iq; + (XMPPIQ *)iqvCardRequestForJID:(XMPPJID *)jid; - (void)addAddress:(XMPPvCardTempAdr *)adr; - (void)removeAddress:(XMPPvCardTempAdr *)adr; - (void)clearAddresses; - (void)addLabel:(XMPPvCardTempLabel *)label; - (void)removeLabel:(XMPPvCardTempLabel *)label; - (void)clearLabels; - (void)addTelecomsAddress:(XMPPvCardTempTel *)tel; - (void)removeTelecomsAddress:(XMPPvCardTempTel *)tel; - (void)clearTelecomsAddresses; - (void)addEmailAddress:(XMPPvCardTempEmail *)email; - (void)removeEmailAddress:(XMPPvCardTempEmail *)email; - (void)clearEmailAddresses; @end
下面是标准的一个小例子：
<?xml version="1.0" encoding="UTF-8"?> <vcards xmlns="urn:ietf:params:xml:ns:vcard-4.0"> <vcard> <tel> <parameters> <type> <text>work</text> </type> </parameters> <uri>tel:+1-111-555-1212</uri> </tel> <adr> <parameters> <type><text>work</text></type> <label><text>100 Waters Edge Baytown, LA 30314 United States of America</text></label> </parameters> </adr> <email><text>forrestgump@example.com</text></email> </vcard> </vcards>
关于这个类的说明，就简单讲一讲。
@interface XMPPvCardCoreDataStorage : XMPPCoreDataStorage < XMPPvCardAvatarStorage, XMPPvCardTempModuleStorage> + (instancetype)sharedInstance; @end
它是一个单例类，直接与数据库有关。它遵守了XMPPvCardAvatarStorage，表示头像模块的存储代理，就可以将电子头像也写入电子名片数据库存储中。
遵守了XMPPvCardTempModuleStorage，就可以直接通过XMPPvCardTemp类对电子名片进行增、删、改、查了。
继承于XMPPModule的类，主要是提供直接操作数据库的操作。
@interface XMPPvCardTempModule : XMPPModule
{
id <XMPPvCardTempModuleStorage> __strong _xmppvCardTempModuleStorage;
XMPPIDTracker *_myvCardTracker;
}
@property(nonatomic, strong, readonly) id <XMPPvCardTempModuleStorage> xmppvCardTempModuleStorage;
@property(nonatomic, strong, readonly) XMPPvCardTemp *myvCardTemp;
- (id)initWithvCardStorage:(id <XMPPvCardTempModuleStorage>)storage;
- (id)initWithvCardStorage:(id <XMPPvCardTempModuleStorage>)storage dispatchQueue:(dispatch_queue_t)queue;
// 若本地没有该电子名片，则从服务器提求
- (void)fetchvCardTempForJID:(XMPPJID *)jid;
// 获取某个jid的电子名片，是否忽略本地所存储的电子名片
- (void)fetchvCardTempForJID:(XMPPJID *)jid ignoreStorage:(BOOL)ignoreStorage;
// 获取某个jid的电子名片，是否自动从服务器提求
- (XMPPvCardTemp *)vCardTempForJID:(XMPPJID *)jid shouldFetch:(BOOL)shouldFetch;
// 这个API用于将电子名片存储到本地数据库，然后发送到服务器
- (void)updateMyvCardTemp:(XMPPvCardTemp *)vCardTemp;
@end
@protocol XMPPvCardTempModuleDelegate
@optional
- (void)xmppvCardTempModule:(XMPPvCardTempModule *)vCardTempModule
didReceivevCardTemp:(XMPPvCardTemp *)vCardTemp
forJID:(XMPPJID *)jid;
- (void)xmppvCardTempModuleDidUpdateMyvCard:(XMPPvCardTempModule *)vCardTempModule;
- (void)xmppvCardTempModule:(XMPPvCardTempModule *)vCardTempModule failedToUpdateMyvCard:(NSXMLElement *)error;
@end
@protocol XMPPvCardTempModuleStorage <NSObject>
- (BOOL)configureWithParent:(XMPPvCardTempModule *)aParent queue:(dispatch_queue_t)queue;
- (XMPPvCardTemp *)vCardTempForJID:(XMPPJID *)jid xmppStream:(XMPPStream *)stream;
- (void)setvCardTemp:(XMPPvCardTemp *)vCardTemp forJID:(XMPPJID *)jid xmppStream:(XMPPStream *)stream;
- (XMPPvCardTemp *)myvCardTempForXMPPStream:(XMPPStream *)stream;
- (BOOL)shouldFetchvCardTempForJID:(XMPPJID *)jid xmppStream:(XMPPStream *)stream;
@end激活电子名片功能，步骤如下：
// 电子名片数据存储 XMPPvCardCoreDataStorage *vCardStorage = [XMPPvCardCoreDataStorage sharedInstance]; // 添加电子名片模块 _vCardModule = [[XMPPvCardTempModule alloc] initWithvCardStorage: vCardStorage]; // 激活 [_vCardModule activate:_xmppStream];
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