一個相似backbone路由的純淨route ( 前端路由客戶端路由 backbone路由 )

時間 2019-11-17

標籤一個相似 backbone 路由純淨 route 前端客戶端欄目系統網絡简体版

原文原文鏈接

你們用backbone、angular，可能都習慣了內置的路由，這兩個框架的路由都是很是優秀的，強大而簡單。git

客戶端（瀏覽器）路由原理其實比較簡單，其實就是監聽hash的變化。github

在以前的架構探討中，說到director.js這個路由類庫很差使，那麼，在這一篇，咱們嘗試自行實現一個簡潔並且很是好使的路由類庫。正則表達式

原理先介紹，無非幾個步驟：瀏覽器

創建配置表（字符串路徑和函數的映射）
監聽路由（onhashchange）
處理路由變化，跟配置表的路徑作匹配
- 路徑轉化爲正則表達式
- 正則exec，匹配+抽取參數

其中難點就在於路徑轉化爲正則表達式，director沒作好就是這一步，而backbone則作得很是很是強大，那麼咱們能夠嘗試把backbone這一塊代碼摳出來。架構

路由表：app

    var Route = root.Route = {
        init: function (map) {
            var defaultAction = map['*'];
            if(defaultAction){
                Route.defaultAction = defaultAction;
                delete map['*'];
            }
            Route.routes = map;
            init();
            onchange();
        },
        routes: {},
        defaultAction: null
    };

監聽路由變化：框架

    /**
     * 這段判斷，引用於director：https://github.com/flatiron/director
     */
    function init(){
        if ('onhashchange' in window && (document.documentMode === undefined
            || document.documentMode > 7)) {
            // At least for now HTML5 history is available for 'modern' browsers only
            if (this.history === true) {
                // There is an old bug in Chrome that causes onpopstate to fire even
                // upon initial page load. Since the handler is run manually in init(),
                // this would cause Chrome to run it twise. Currently the only
                // workaround seems to be to set the handler after the initial page load
                // http://code.google.com/p/chromium/issues/detail?id=63040
                setTimeout(function() {
                    window.onpopstate = onchange;
                }, 500);
            }
            else {
                window.onhashchange = onchange;
            }
            this.mode = 'modern';
        } else {
            throw new Error('sorry, your browser doesn\'t support route');
        }
    }

處理路由變化，先拼湊正則表達式：函數

    /**
     * 引自backbone，很是牛逼的正則
     * @param route
     * @returns {RegExp}
     */
    function getRegExp(route){
        var optionalParam = /\((.*?)\)/g;
        var namedParam    = /(\(\?)?:\w+/g;
        var splatParam    = /\*\w+/g;
        var escapeRegExp  = /[\-{}\[\]+?.,\\\^$|#\s]/g;
        route = route.replace(escapeRegExp, '\\$&')
            .replace(optionalParam, '(?:$1)?')
            .replace(namedParam, function(match, optional) {
                return optional ? match : '([^/?]+)';
            })
            .replace(splatParam, '([^?]*?)');
        return new RegExp('^' + route + '(?:\\?([\\s\\S]*))?$');
    }

從原來的：module2/:name變成標準的正則表達式，箇中奧妙你們自行頓悟測試

循環匹配：this

    function onchange(onChangeEvent){
        var newURL = onChangeEvent && onChangeEvent.newURL || window.location.hash;
        var url = newURL.replace(/.*#/, '');
        var found = false;
        for (var path in Route.routes) {
            var reg = getRegExp(path);
            var result = reg.exec(url);
            if(result && result[0] && result[0] != ''){
                var handler = Route.routes[path];
                handler && handler.apply(null, result.slice(1));
                found = true;
            }
        }
        if(!found && Route.defaultAction){
            Route.defaultAction();
        }
    }

而後。。。作個簡單的測試：

<script src="libs/backbone-route.js"></script>
<script>

    Route.init({
        'module1': function(){
            console.log(1);
        },
        'module2/:name/:age': function(){
            console.log(2, arguments);
        },
        'module3(/:name)(/:age)': function(){
            console.log('3', arguments);
        },
        '*': function(){
            console.log(404);
        }
    });
</script>