vue-router源码实例详解

import Vue from 'vue'
import VueRouter from 'vue-router'

Vue.use(VueRouter)

const Home = { template: '<div>home</div>' }
const Foo = { template: '<div>foo</div>' }
const Bar = { template: '<div>bar</div>' }

const router = new VueRouter({
  mode: 'history',
  base: __dirname,
  routes: [
    { path: '/', component: Home },
    { path: '/foo', component: Foo },
    { path: '/bar', component: Bar }
  ]
})

new Vue({
  router,
  template: `    <div id="app">      <h1>Basic</h1>      <ul>        <li><router-link to="/">/</router-link></li>        <li><router-link to="/foo">/foo</router-link></li>        <li><router-link to="/bar">/bar</router-link></li>        <router-link tag="li" to="/bar" :event="['mousedown', 'touchstart']">          <a>/bar</a>        </router-link>      </ul>      <router-view class="view"></router-view>    </div>
  `
}).$mount('#app')

import type { Matcher } from './create-matcher'export default class VueRouter {  constructor (options: RouterOptions = {}) {    this.app = null    this.apps = []    this.options = options    this.beforeHooks = []    this.resolveHooks = []    this.afterHooks = []    this.matcher = createMatcher(options.routes || [], this)    let mode = options.mode || 'hash'    this.fallback = mode === 'history' && !supportsPushState && options.fallback !== false    if (this.fallback) {
      mode = 'hash'
    }    if (!inBrowser) {
      mode = 'abstract'
    }    this.mode = mode    switch (mode) {      case 'history':        this.history = new HTML5History(this, options.base)        break      case 'hash':        this.history = new HashHistory(this, options.base, this.fallback)        break      case 'abstract':        this.history = new AbstractHistory(this, options.base)        break      default:        if (process.env.NODE_ENV !== 'production') {
          assert(false, `invalid mode: ${mode}`)
        }
    }
  }

  init (app: any /* Vue component instance */) {    this.apps.push(app)    // main app already initialized.    if (this.app) {      return
    }    this.app = app    const history = this.history    if (history instanceof HTML5History) {
      history.transitionTo(history.getCurrentLocation())
    } else if (history instanceof HashHistory) {      const setupHashListener = () => {
        history.setupListeners()
      }
      history.transitionTo(
        history.getCurrentLocation(),
        setupHashListener,
        setupHashListener
      )
    }

    history.listen(route => {      this.apps.forEach((app) => {
        app._route = route
      })
    })
  }

  getMatchedComponents (to?: RawLocation | Route): Array<any> {    const route: any = to
      ? to.matched
        ? to
        : this.resolve(to).route
      : this.currentRoute    if (!route) {      return []
    }    return [].concat.apply([], route.matched.map(m => {      return Object.keys(m.components).map(key => {        return m.components[key]
      })
    }))
  }

}

function createMatcher (
  routes,
  router
) {  var ref = createRouteMap(routes);  var pathList = ref.pathList;  var pathMap = ref.pathMap;  var nameMap = ref.nameMap;  
  function addRoutes (routes) {
    createRouteMap(routes, pathList, pathMap, nameMap);
  }   function match (
    raw,
    currentRoute,
    redirectedFrom
  ) {    var location = normalizeLocation(raw, currentRoute, false, router);    var name = location.name;    // 命名路由处理    if (name) {      // nameMap[name]的路由记录      var record = nameMap[name];
      ...
        location.path = fillParams(record.path, location.params, ("named route \"" + name + "\""));        // _createRoute用于创建路由        return _createRoute(record, location, redirectedFrom)
    } else if (location.path) {      // 普通路由处理
    }    // no match    return _createRoute(null, location)
  }  return {
    match: match,
    addRoutes: addRoutes
  }
}

function createRouteMap (
  routes,
  oldPathList,
  oldPathMap,
  oldNameMap) {  // 用于控制匹配优先级  var pathList = oldPathList || [];  // name 路由 map  var pathMap = oldPathMap || Object.create(null);  // name 路由 map  var nameMap = oldNameMap || Object.create(null);  // 遍历路由配置对象增加路由记录
  routes.forEach(function (route) {
    addRouteRecord(pathList, pathMap, nameMap, route);
  });  // 确保通配符总是在pathList的最后，保证最后匹配  for (var i = 0, l = pathList.length; i < l; i++) {    if (pathList[i] === '*') {
      pathList.push(pathList.splice(i, 1)[0]);
      l--;
      i--;
    }
  }  return {    pathList: pathList,    pathMap: pathMap,    nameMap: nameMap
  }
}

const router = new VueRouter({  routes: [    // 下面的对象就是 route record
    { path: '/foo', component: Foo,      children: [        // 这也是个 route record
        { path: 'bar', component: Bar }
      ]
    }
  ]
})

function addRouteRecord (
  pathList,
  pathMap,
  nameMap,
  route,
  parent,
  matchAs
) {  var path = route.path;  var name = route.name;  var normalizedPath = normalizePath(
    path,    parent
  );  var record = {
    path: normalizedPath,
    regex: compileRouteRegex(normalizedPath, pathToRegexpOptions),
    components: route.components || { default: route.component },
    instances: {},
    name: name,    parent: parent,
    matchAs: matchAs,
    redirect: route.redirect,
    beforeEnter: route.beforeEnter,
    meta: route.meta || {},
    props: route.props == null
      ? {}
      : route.components
        ? route.props
        : { default: route.props }
  };  if (route.children) {
    route.children.forEach(function (child) {
      addRouteRecord(pathList, pathMap, nameMap, child, record, childMatchAs);
    });
  }  if (route.alias !== undefined) {    // 如果有别名的情况
  }  if (!pathMap[record.path]) {
    pathList.push(record.path);
    pathMap[record.path] = record;
  }
}

var History = function History (router, base) {  this.router = router;  this.base = normalizeBase(base);  this.current = START;  this.pending = null;  this.ready = false;  this.readyCbs = [];  this.readyErrorCbs = [];  this.errorCbs = [];
};

function createRoute (  record,
  location,
  redirectedFrom,
  router
) {
  var stringifyQuery$$1 = router && router.options.stringifyQuery;

  var query = location.query || {};
  try {
    query = clone(query);
  } catch (e) {}

  var route = {
    name: location.name || (record && record.name),
    meta: (record && record.meta) || {},
    path: location.path || '/',
    hash: location.hash || '',
    query: query,
    params: location.params || {},
    fullPath: getFullPath(location, stringifyQuery$$1),
    matched: record ? formatMatch(record) : []
  };  if (redirectedFrom) {
    route.redirectedFrom = getFullPath(redirectedFrom, stringifyQuery$$1);
  }  return Object.freeze(route)
}

History.prototype.transitionTo = function transitionTo (location, onComplete, onAbort) {    var this$1 = this;  var route = this.router.match(location, this.current);  this.confirmTransition(route, function () {    this$1.updateRoute(route);
    onComplete && onComplete(route);    this$1.ensureURL();    // fire ready cbs once    if (!this$1.ready) {      this$1.ready = true;      this$1.readyCbs.forEach(function (cb) { cb(route); });
    }
  }, function (err) {    if (onAbort) {
      onAbort(err);
    }    if (err && !this$1.ready) {      this$1.ready = true;      this$1.readyErrorCbs.forEach(function (cb) { cb(err); });
    }
  });
};

var HTML5History = (function (History$$1) {  function HTML5History (router, base) {    var this$1 = this;

    History$$1.call(this, router, base);    var initLocation = getLocation(this.base);    window.addEventListener('popstate', function (e) {      var current = this$1.current;      var location = getLocation(this$1.base);      if (this$1.current === START && location === initLocation) {        return
      }
    });
  }  if ( History$$1 ) HTML5History.__proto__ = History$$1;
  HTML5History.prototype = Object.create( History$$1 && History$$1.prototype );
  HTML5History.prototype.constructor = HTML5History;


  HTML5History.prototype.push = function push (location, onComplete, onAbort) {    var this$1 = this;    var ref = this;    var fromRoute = ref.current;    this.transitionTo(location, function (route) {
      pushState(cleanPath(this$1.base + route.fullPath));
      handleScroll(this$1.router, route, fromRoute, false);
      onComplete && onComplete(route);
    }, onAbort);
  };

  HTML5History.prototype.replace = function replace (location, onComplete, onAbort) {    var this$1 = this;    var ref = this;    var fromRoute = ref.current;    this.transitionTo(location, function (route) {
      replaceState(cleanPath(this$1.base + route.fullPath));
      handleScroll(this$1.router, route, fromRoute, false);
      onComplete && onComplete(route);
    }, onAbort);
  };  return HTML5History;
}(History))

function getLocation (base) {  var path = window.location.pathname;  if (base && path.indexOf(base) === 0) {
    path = path.slice(base.length);
  }  return (path || '/') + window.location.search + window.location.hash
}

var View = {
  name: 'router-view',
  functional: true,
  props: {
    name: {
      type: String,      default: 'default'
    }
  },
  render: function render (_, ref) {    var props = ref.props;    var children = ref.children;    var parent = ref.parent;    var data = ref.data;    // 解决嵌套深度问题
    data.routerView = true;    var h = parent.$createElement;    var name = props.name;    // route    var route = parent.$route;    // 缓存    var cache = parent._routerViewCache || (parent._routerViewCache = {});    // 组件的嵌套深度    var depth = 0;    // 用于设置class值    var inactive = false;    // 组件的嵌套深度    while (parent && parent._routerRoot !== parent) {      if (parent.$vnode && parent.$vnode.data.routerView) {
        depth++;
      }      if (parent._inactive) {
        inactive = true;
      }      parent = parent.$parent;
    }
    data.routerViewDepth = depth;    if (inactive) {      return h(cache[name], data, children)
    }    var matched = route.matched[depth];    if (!matched) {
      cache[name] = null;      return h()
    }    var component = cache[name] = matched.components[name];

    data.registerRouteInstance = function (vm, val) {      // val could be undefined for unregistration      var current = matched.instances[name];      if (
        (val && current !== vm) ||
        (!val && current === vm)
      ) {
        matched.instances[name] = val;
      }
    }

    ;(data.hook || (data.hook = {})).prepatch = function (_, vnode) {
      matched.instances[name] = vnode.componentInstance;
    };    var propsToPass = data.props = resolveProps(route, matched.props && matched.props[name]);    if (propsToPass) {
      propsToPass = data.props = extend({}, propsToPass);      var attrs = data.attrs = data.attrs || {};      for (var key in propsToPass) {        if (!component.props || !(key in component.props)) {
          attrs[key] = propsToPass[key];
          delete propsToPass[key];
        }
      }
    }    return h(component, data, children)
  }
};