『ios』JLRoutes源码分析

2018-11-29 本文已影响44人 butterflyer

阅读源码是目前沉淀自己的最好方式~

image.png

route 都是知道什么意思，路由的意思，如果没接触vue之前我对路由也只是了解的比较浅，但现在还算可以了。当然 JLRoutes路由跟vue还是有差别的。它是用了类似window.location.href="http://www.xxx.com/path?params=xxx"这种方式。这算是点开胃菜吧。

如果要搞懂JLRoutes必须要搞懂的就是url的链接组成了。

http://www.xxxx.com:8080/news/index.asp?boardID=5&ID=24618&page=1#name

http: 是协议部分后面//为分隔符这里可以使http也可以是https各种协议
www.xxxx.com 域名当然也可以用ip作为域名地址比如这里换成192.168.1.124也是可以的
8080 端口号域名和端口号用www.xxxx.com分开
4./news/ 虚目录部分
5.index.asp文件名
6.最后面的#name是锚
7.?boardID=5&ID=24618&page=1 这里是参数部分

JLRoutes组成

JLRoutes //这是我们主要接触到的类里面包含了各种注册方法取消注册方法

The JLRoutes class is the main entry-point into the JLRoutes framework. Used for accessing schemes, managing routes, and routing URLs.

JLRParsingUtilities //解析路由的工具类

JLRRouteDefinition//根据路由拼接成我们需要的params

JLRRouteDefinition is a model object representing a registered route, including the URL scheme, route pattern, and priority.

JLRRouteRequest //这个也是拼接我们需要的params
JLRRouteRequest is a model representing a request to route a URL.
It gets parsed into path components and query parameters, which are then used by JLRRouteDefinition to attempt a match.

JLRRouteResponse // JLRRouteResponse is the response from attempting to route a JLRRouteRequest.

根据一条条线分析源码

先看一个方法

 [[JLRoutes routesForScheme:scheme] addRoute:@"/push/:controller"handler:^BOOL(NSDictionary<NSString *,id> * _Nonnull parameters) {
        Class class = NSClassFromString(parameters[@"controller"]);
        
        UIViewController *nextVC = [[class alloc] init];
        [self paramToVc:nextVC param:parameters];
        UIViewController *currentVc = [self currentViewController];
        [currentVc.navigationController pushViewController:nextVC animated:YES];       
        return YES;
    }];

先看init这条线

+ (instancetype)globalRoutes
{
    return [self routesForScheme:JLRoutesGlobalRoutesScheme];
}

+ (instancetype)routesForScheme:(NSString *)scheme
{
    JLRoutes *routesController = nil;
    
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        routeControllersMap = [[NSMutableDictionary alloc] init];
    });
    
    if (!routeControllersMap[scheme]) {
        routesController = [[self alloc] init];
        routesController.scheme = scheme;
        routeControllersMap[scheme] = routesController;
    }
    routesController = routeControllersMap[scheme];
    return routesController;
}

我们可以看到routeControllersMap这个字典，被放到单例里面进行初始化，所以JLRoutes中的路由其实就是在这里面啦。

registerRoute 注册

- (void)addRoutes:(NSArray<NSString *> *)routePatterns handler:(BOOL (^)(NSDictionary<NSString *, id> *parameters))handlerBlock //这个handlerBlock就是回调函数哦
{
    for (NSString *routePattern in routePatterns) {
        [self addRoute:routePattern handler:handlerBlock];
    }
}
一直往下走
- (void)addRoute:(NSString *)routePattern priority:(NSUInteger)priority handler:(BOOL (^)(NSDictionary<NSString *, id> *parameters))handlerBlock
{
    NSArray <NSString *> *optionalRoutePatterns = [JLRParsingUtilities expandOptionalRoutePatternsForPattern:routePattern];
    JLRRouteDefinition *route = [[JLRRouteDefinition alloc] initWithScheme:self.scheme pattern:routePattern priority:priority handlerBlock:handlerBlock];//在这个地方
    
    if (optionalRoutePatterns.count > 0) {
        // there are optional params, parse and add them
        for (NSString *pattern in optionalRoutePatterns) {
            [self _verboseLog:@"Automatically created optional route: %@", route];
            JLRRouteDefinition *optionalRoute = [[JLRRouteDefinition alloc] initWithScheme:self.scheme pattern:pattern priority:priority handlerBlock:handlerBlock];
            [self _registerRoute:optionalRoute]; 
        }
        return;
    }
    
    [self _registerRoute:route];
}

先看 [self _registerRoute:optionalRoute]; 这个函数

- (void)_registerRoute:(JLRRouteDefinition *)route
{
    if (route.priority == 0 || self.mutableRoutes.count == 0) {
        [self.mutableRoutes addObject:route];
    } else {
        NSUInteger index = 0;
        BOOL addedRoute = NO;
        
        // search through existing routes looking for a lower priority route than this one
        for (JLRRouteDefinition *existingRoute in [self.mutableRoutes copy]) {
            if (existingRoute.priority < route.priority) {
                // if found, add the route after it
                [self.mutableRoutes insertObject:route atIndex:index];
                addedRoute = YES;
                break;
            }
            index++;
        }
        
        // if we weren't able to find a lower priority route, this is the new lowest priority route (or same priority as self.routes.lastObject) and should just be added
        if (!addedRoute) {
            [self.mutableRoutes addObject:route];
        }
    }
}

我们可以看到route加到了一个由单例保存的，可变数组中。其实这一步就完成了注册路由的过程。

回调函数 handlerBlock

JLRRouteDefinition *route = [[JLRRouteDefinition alloc] initWithScheme:self.scheme pattern:routePattern priority:priority handlerBlock:handlerBlock];//在这个地方 会拼接路由

- (instancetype)initWithScheme:(NSString *)scheme pattern:(NSString *)pattern priority:(NSUInteger)priority handlerBlock:(BOOL (^)(NSDictionary *parameters))handlerBlock
{
    if ((self = [super init])) {
        self.scheme = scheme;
        self.pattern = pattern;
        self.priority = priority;
        self.handlerBlock = handlerBlock; //在这里会把这个block保存到 JLRRouteDefinition对象中，记住，会保存在这
      
        if ([pattern characterAtIndex:0] == '/') {
            pattern = [pattern substringFromIndex:1];
        }
        
        self.patternComponents = [pattern componentsSeparatedByString:@"/"];
    }
    return self;
}

点击页面跳转配合 handlerBlock 回调

 NSString *url = @"RouteScheme://push/XHTestController?titleText=fromFirst&love=哈哈";
    NSCharacterSet *allowCharacters = [[NSCharacterSet characterSetWithCharactersInString:name] invertedSet];
    NSString *encodedUrl = [url stringByAddingPercentEncodingWithAllowedCharacters:allowCharacters];
 
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:encodedUrl]];

当调用openURL的时候，会调用系统

- (BOOL)application:(UIApplication *)app openURL:(NSURL *)url options:(NSDictionary<NSString *,id> *)options{

        return [[JLRoutes routesForScheme:@"Route"]routeURL:url];
 这里的url就是上面的RouteScheme://push/XHTestController?titleText=fromFirst&love=哈哈
}

继续往下走

- (BOOL)routeURL:(NSURL *)URL
{
    return [self _routeURL:URL withParameters:nil executeRouteBlock:YES];
}

下面这个方法有点长,不过我都会在代码里标上解析

- (BOOL)_routeURL:(NSURL *)URL withParameters:(NSDictionary *)parameters executeRouteBlock:(BOOL)executeRouteBlock
{
    if (!URL) {
        return NO;
    }
    
    [self _verboseLog:@"Trying to route URL %@", URL];
    
    BOOL didRoute = NO;
    JLRRouteRequest *request = [[JLRRouteRequest alloc] initWithURL:URL alwaysTreatsHostAsPathComponent:alwaysTreatsHostAsPathComponent];//在这里初始化一个request对象在对象里拼接后面我们需要的 pathComponents  queryParams URL
    
    for (JLRRouteDefinition *route in [self.mutableRoutes copy]) {//遍历刚刚保存路由的可变数组 在这里为了防止发生变化，把他改了不可变数组
        // check each route for a matching response
        JLRRouteResponse *response = [route routeResponseForRequest:request decodePlusSymbols:shouldDecodePlusSymbols]; //因为这里我们需要遍历数组中保存的每一个路由，所以我们会根据respones里面的ismatch来进行判断，选出我们当前在用的那个路由，其他的路由直接跳出循环
        if (!response.isMatch) {
            continue;
        }
        
        [self _verboseLog:@"Successfully matched %@", route];
        
        if (!executeRouteBlock) {
            // if we shouldn't execute but it was a match, we're done now
            return YES;
        }
        
        // configure the final parameters
        NSMutableDictionary *finalParameters = [NSMutableDictionary dictionary];
        [finalParameters addEntriesFromDictionary:response.parameters];
        [finalParameters addEntriesFromDictionary:parameters]; //在这里拼接处最后需要返回handlerBlock中的参数 请看下图
        [self _verboseLog:@"Final parameters are %@", finalParameters];

![image.png](https://img.haomeiwen.com/i2440780/e675481df1962163.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

        
        didRoute = [route callHandlerBlockWithParameters:finalParameters];//请注意看里，这里直接调用callHandlerBlockWithParameters这个函数走block，把finalParameters传到外面。
到这里大体的一个流程我们就走了一遍。
        
        if (didRoute) {
            // if it was routed successfully, we're done
            break;
        }
    }
    
    if (!didRoute) {
        [self _verboseLog:@"Could not find a matching route"];
    }
    
    // if we couldn't find a match and this routes controller specifies to fallback and its also not the global routes controller, then...
    if (!didRoute && self.shouldFallbackToGlobalRoutes && ![self _isGlobalRoutesController]) {
        [self _verboseLog:@"Falling back to global routes..."];
        didRoute = [[JLRoutes globalRoutes] _routeURL:URL withParameters:parameters executeRouteBlock:executeRouteBlock];
    }
    
    // if, after everything, we did not route anything and we have an unmatched URL handler, then call it
    if (!didRoute && executeRouteBlock && self.unmatchedURLHandler) {
        [self _verboseLog:@"Falling back to the unmatched URL handler"];
        self.unmatchedURLHandler(self, URL, parameters);
    }
    
    return didRoute;
}

通过
[[JLRoutes routesForScheme:scheme] addRoute:@"/push/:controller"handler:^BOOL(NSDictionary<NSString *,id> * _Nonnull parameters) {

}];

我们可以很清楚的看到，通过一系列的骚操作，把跳转页面的操作搞到了一起。
后面还会另开新篇找些JLRoutes的复杂运用。

『ios』JLRoutes源码分析

JLRoutes组成

根据一条条线分析源码

先看init这条线

registerRoute 注册

回调函数 handlerBlock

点击页面跳转配合 handlerBlock 回调

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『ios』JLRoutes源码分析

JLRoutes组成

根据一条条线分析源码

先看init这条线

registerRoute 注册

回调函数 handlerBlock

点击页面跳转 配合 handlerBlock 回调

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点击页面跳转配合 handlerBlock 回调