ReactiveCocoa用法示例(二)

知识点

• RACSignal与OC对象方法的绑定
• RACSignal与OC对象属性的绑定
• [RACSignal merge:], Merge操作的使用
• [RACSignal combineLatest: reduce:^id(){}], Combine和reduce操作的使用
• [RACSignal return:nil] 与[RACSignal empty], nil信号和空信号的区别

示例项目功能

• 点击电子发票 纸质发票 个人 公司四个按钮 界面作出变化
• 根据四种状态检查Textfiled内容是否输入错误
• 输入错误Toast弹出错误内容
• 输入正确Alert弹出确认信息

示例项目地址

github: https://github.com/heeween/RACComand2.git
用到的城市选择器属于Jonhory

构建电子发票 纸质发票 个人 公司四个按钮的RACCommand对象

// GBInvoiceContentViewModel.m中代码    self.personalCmd = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {        return [RACSignal return:@(Invoice_Owner_Personal)];    }];    self.companyCmd = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {        return [RACSignal return:@(Invoice_Owner_Company)];    }];    self.nonPaperCmd = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {        return [RACSignal return:@(Invoice_Source_NonPaper)];    }];    self.paperCmd = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {        return [RACSignal return:@(Invoice_Source_Paper)];    }];

在控制器中将RACCommand对象和按钮事件绑定

// GBInvoiceContentController.m 中代码    self.contentView.ownerItemView.personalButton.rac_command = self.viewModel.personalCmd;    self.contentView.ownerItemView.companyButton.rac_command = self.viewModel.companyCmd;    self.sourceView.nonPaperButton.rac_command = self.viewModel.nonPaperCmd;    self.sourceView.paperButton.rac_command = self.viewModel.paperCmd;

将上述四个command的包含的信号合并为source何owner两个信号

// GBInvoiceContentViewModel.m中代码    RACSignal *personalSignal = [[self.personalCmd executionSignals] switchToLatest];    RACSignal *companySignal = [[self.companyCmd executionSignals] switchToLatest];    RACSignal *nonPaperSignal = [[self.nonPaperCmd executionSignals] switchToLatest];    RACSignal *paperSignal = [[self.paperCmd executionSignals] switchToLatest];    self.ownerSignal = [RACSignal merge:@[personalSignal,companySignal]];    self.sourceSignal = [RACSignal merge:@[nonPaperSignal,paperSignal]];

分别将source和owner信号绑定对应的view上

// GBInvoiceContentController.m 中代码    RAC(self.sourceView,type) = self.viewModel.sourceSignal;    RAC(self.confirmView,type) = self.viewModel.sourceSignal;    RAC(self.addressView,type) = self.viewModel.sourceSignal;    RAC(self.contentView,type) = self.viewModel.ownerSignal;

将source和owner两个信号合并为动画信号

// GBInvoiceContentViewModel.m中代码    self.animateSignal = [RACSignal merge:@[self.ownerSignal,self.sourceSignal]];

将动画信号绑定到控制器的动画方法

// GBInvoiceContentController.m 中代码    [self rac_liftSelector:@selector(animatieUpdateSubview:) withSignals:self.viewModel.animateSignal, nil];/** 动画子控件 */- (void)animatieUpdateSubview:(id)obj {    [UIView animateWithDuration:0.3 animations:^{        [self.view layoutIfNeeded];    }];}

收集控制器中各输入框的信号,并且绑定到viewmode中发票对象的属性上

// GBInvoiceContentController.m 中代码        self.viewModel.companyNameSignal = self.contentView.companyNameItemView.inputField.rac_textSignal;        self.viewModel.taxNumberSignal = self.contentView.taxPayerIDItemView.inputField.rac_textSignal;        self.viewModel.remarkSignal = self.contentView.markField.rac_textSignal;        self.viewModel.receiverSignal = self.addressView.contactNameItemView.inputField.rac_textSignal;        self.viewModel.phoneSignal = self.addressView.contactPhoneItemView.inputField.rac_textSignal;        self.viewModel.regionSignal = self.addressView.contactAddressItemView.inputField.rac_textSignal;        self.viewModel.minAddressSignal = self.addressView.contactAddressDescItemView.inputField.rac_textSignal;        self.viewModel.emailSignal = self.addressView.contactMailItemView.inputField.rac_textSignal;        RAC(self.viewModel.invoice,companyName) = self.viewModel.companyNameSignal;        RAC(self.viewModel.invoice,taxNumber) = self.viewModel.taxNumberSignal;        RAC(self.viewModel.invoice,receiver) = self.viewModel.receiverSignal;        RAC(self.viewModel.invoice,region) = self.viewModel.regionSignal;        RAC(self.viewModel.invoice,minAddress) = self.viewModel.minAddressSignal;        RAC(self.viewModel.invoice,email) = self.viewModel.emailSignal;

在viewmodel中根据source和owner信号,对各个输入框的信号进行merge和reduce操作,整合成错误字符串信号errorStringSignal

// GBInvoiceContentViewModel.m中代码- (RACSignal *)errorStringSignal {    if (!_errorStringSignal) {        RACSignal *companyNameError = [self.companyNameSignal map:^id(NSString *value) {            if (value.length <= 0) {                return @"公司名称不能为空";            }else {                return @"";            }        }];        RACSignal *taxNumberError = [self.taxNumberSignal map:^id(NSString *value) {            if (value.length <= 0) {                return @"纳税人识别号不能为空";            }else if (![value isTaxNumber]) {                return @"纳税人识别号输入不正确";            }else {                return @"";            }        }];        RACSignal *receiverError = [self.receiverSignal map:^id(NSString *value) {            return value.length > 0 ? @"" : @"联系人不能为空";        }];        RACSignal *phoneError = [self.phoneSignal map:^id(NSString *value) {            if (value.length <= 0) {                return @"电话不能为空";            }else if (value.length != 11) {                return @"电话输入不正确";            }else {                return @"";            }        }];        RACSignal *regionError = [self.regionSignal map:^id(NSString *value) {            return value.length > 0 ? @"" : @"地址不能为空";        }];        RACSignal *minaddressError = [self.minAddressSignal map:^id(NSString *value) {            return value.length > 0 ? @"" : @"详细地址不能为空";        }];        RACSignal *emailError = [self.emailSignal map:^id(NSString *value) {            if (value.length <= 0) {                return @"邮箱不能为空";            }else if (![value isEmail]) {                return @"邮箱输入不正确";            }else {                return @"";            }        }];        NSDictionary *sourceDict =        @{          @(Invoice_Source_Paper):              [RACSignal combineLatest:@[receiverError,phoneError,regionError,minaddressError] reduce:^id(NSString *receiver, NSString *phone,NSString *region,NSString *minaddress){                  NSMutableArray *array = [NSMutableArray array];                  if (receiver.length > 0) { [array addObject:receiver]; }                  if (phone.length > 0) { [array addObject:phone]; }                  if (region.length > 0) { [array addObject:region]; }                  if (minaddress.length > 0) { [array addObject:minaddress]; }                  return array;              }],          @(Invoice_Source_NonPaper):              [RACSignal combineLatest:@[receiverError,phoneError,emailError] reduce:^id(NSString *receiver, NSString *phone,NSString *email){                  NSMutableArray *array = [NSMutableArray array];                  if (receiver.length > 0) { [array addObject:receiver]; }                  if (phone.length > 0) { [array addObject:phone]; }                  if (email.length > 0) { [array addObject:email]; }                  return array;              }]          };        RACSignal *sourceError = [RACSignal switch:self.sourceSignal cases:sourceDict default:nil];        NSDictionary *ownerDict =        @{          @(Invoice_Owner_Personal): [RACSignal return:nil],          @(Invoice_Owner_Company):              [RACSignal combineLatest:@[companyNameError,taxNumberError] reduce:^id(NSString *companyName, NSString *taxNumber){                  NSMutableArray *array = [NSMutableArray array];                  if (companyName.length > 0) { [array addObject:companyName]; }                  if (taxNumber.length > 0) { [array addObject:taxNumber]; }                  return array;              }]          };        RACSignal *ownerError = [RACSignal switch:self.ownerSignal cases:ownerDict default:nil];        _errorStringSignal = [RACSignal combineLatest:@[sourceError,ownerError] reduce:^id(NSArray *sourceArray, NSArray *ownerArray){            NSMutableArray *array = [NSMutableArray array];            [array addObjectsFromArray:sourceArray];            [array addObjectsFromArray:ownerArray];            return array;        }];    }    return _errorStringSignal;}

把errorStringSignal和errorstring属性

• 这步看似多次一举,实则是因为页面需求并不是每次有错误就弹出,而是在点击下一步的时候才弹出
• 因为先用errorstring属性保存错误值,点击下一步的通过subscriper发出

// GBInvoiceContentController.m 中代码        RAC(self.viewModel,errorStrings) = self.viewModel.errorStringSignal;

创建下一步command,有错误senderror,没有sendcomplete

// GBInvoiceContentViewModel.m中代码- (RACCommand *)nextCmd {    if (!_nextCmd) {        @weakify(self);        _nextCmd = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {            return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {                @strongify(self);                if (self.errorStrings == nil || self.errorStrings.count <= 0) {                    [subscriber sendNext:[self.invoice showParame]];                    [subscriber sendCompleted];                }else {                    [subscriber sendError:[NSError errorWithDomain:@"输入有误" code:0 userInfo:@{@"errorStrings":self.errorStrings}]];                }                return nil;            }];        }];    }    return _nextCmd;}

下一步command与下一步按钮绑定,并且绑定成功和失败信号到对应的控制器方法

// GBInvoiceContentController.m 中代码        self.confirmView.confirmButton.rac_command = self.viewModel.nextCmd;        [self rac_liftSelector:@selector(showAlert:) withSignals:[[self.viewModel.nextCmd executionSignals] switchToLatest], nil];        [self rac_liftSelector:@selector(showError:) withSignals:self.viewModel.nextCmd.errors, nil];/** 输入错误提醒 */- (void)showError:(NSError *)error {    NSArray *errorStrings = error.userInfo[@"errorStrings"];    [CSToastManager setDefaultPosition:CSToastPositionCenter];    [self.view makeToast:[errorStrings componentsJoinedByString:@"  |  "]];}/** 输入成功弹窗 */- (void)showAlert:(id)obj {    GBInvoiceAlert *alertView = [GBInvoiceAlert showWith:obj confirmBlock:nil];    alertView.confirmBtn.rac_command = self.viewModel.confirmCmd;}

创建comfirmCmd

// GBInvoiceContentViewModel.m中代码- (RACCommand *)confirmCmd {    if (!_confirmCmd) {        _confirmCmd = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {            return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {                if (arc4random() % 2 == 0) {                    [subscriber sendNext:@"开票成功"];                    [subscriber sendCompleted];                }else {                    NSError *error = [NSError errorWithDomain:@"开票失败" code:00 userInfo:nil];                    [subscriber sendError:error];                }                return nil;            }];        }];    }    return _confirmCmd;}

最后一步绑定弹窗确定按钮和comfirmCmd,并且绑定成功和失败信号到对应的控制器方法

// GBInvoiceContentController.m 中代码    // 绑定弹窗的成功和失败信号    {        [self rac_liftSelector:@selector(postParamSuccess:) withSignals:[[self.viewModel.confirmCmd executionSignals] switchToLatest], nil];        [self rac_liftSelector:@selector(postParamFailure:) withSignals:self.viewModel.confirmCmd.errors, nil];    }/** 开票成功 */- (void)postParamSuccess:(id)obj {    [self.view makeToast:@"开票成功"];}/** 开票失败 */- (void)postParamFailure:(id)obj {    [self.view makeToast:@"开票失败"];}

1,使用RACComand和RACSigna,可以很方便的拿到各自独立的事件或信号.
2, RAC有大量的信号操作,可以非常方便做业务逻辑.不管是信号合并信号转化都不需要蛋疼的中间变量.
3,RAC有吊炸天的绑定,更是方便了从结果到界面的one step.