javascript regex - 删除查询字符串变量(如果存在) [英] javascript regex - remove a querystring variable if present

问题描述

我需要使用 javascript 重写一个查询.首先，我检查变量是否存在，如果存在，我想用新的搜索词替换它.如果它不存在，那么我只需添加新变量

I need to rewrite a querysting using javascript. First I check to see if the variable is present, if it is I want to replace it with a new search term. If it is not present then I just add the new variable

我可以使用诸如 hat、ufc hat 之类的简单术语来使用它空格是 %20，所以 ufc hat 真的是 ufc%20hat

I'm able to get it to work with simple terms like hat, ufc hat whitespaces are %20, so ufc hat is really ufc%20hat

我遇到了化妆、帽子棒球、咖啡和等术语的问题.茶等.

I run into problem with terms like make-up, hat -baseball, coffee & tea, etc..

什么是合适的正则表达式?

What is the proper regex for this?

下面是我的代码，它不起作用.

Below is my code, which doesn't work.

var url = String(document.location).split('?');
querystring = url[1];
if(querystring.match(/gbn_keywords=/)!=null)
querystring=querystring.replace(/gbn_keywords=[a-zA-Z0-9%20.]+/,"gbn_keywords="+term);
else
querystring=querystring+"&gbn_keywords="+term;

推荐答案

location 对象已经拥有非常好的属性，例如 pathname、hostname 等. 为您提供 URL 的单独部分.使用 .search 属性，而不是尝试将 URL 作为字符串破解(? 可能不仅出现在那个地方).

location objects already have perfectly good properties like pathname, hostname etc. that give you the separate parts of a URL. Use the .search property instead of trying to hack the URL as a string (? may not only appear in that one place).

然后是在 & 字符上拆分的情况(如果您想保持友好，也可能是 ; ，根据 HTML4 B2.2)并检查每个与您要查找的参数相对应.对于一般情况，这需要正确的 URL 解码，因为 g%62n_keywords=... 是拼写相同参数的有效方式.自然而然地，您将需要再次编码，以阻止 & 继续处理下一个参数(以及包含其他无效字符).

It's then a case of splitting on the & character (and maybe ; too if you want to be nice, as per HTML4 B2.2) and checking each parameter against the one you're looking for. For the general case this requires proper URL-decoding, as g%62n_keywords=... is a valid way of spelling the same parameter. On the way out naturally you will need to encode again, to stop & going on to the next parameter (as well as to include other invalid characters).

这里有几个实用函数，您可以使用它们来更轻松地处理查询字符串操作.它们在 location.search 或 link.search 中看到的 ?... 字符串和查找 Object 之间进行转换> 将参数名称映射到值数组(因为表单 url 编码的查询可以有同一参数的多个实例).

Here's a couple of utility functions you can use to cope with query string manipulation more easily. They convert between the ?... string as seen in location.search or link.search and a lookup Object mapping parameter names to arrays of values (since form-url-encoded queries can have multiple instances of the same parameter).

function queryToLookup(query) {
    var lookup= {};
    var params= query.slice(1).split(/[&;]/);
    for (var i= 0; i<params.length; i++) {
        var ix= params[i].indexOf('=');
        if (ix!==-1) {
            var name= decodeURIComponent(params[i].slice(0, ix));
            var value= decodeURIComponent(params[i].slice(ix+1));
            if (!(name in lookup))
                lookup[name]= [];
            lookup[name].push(value);
        }
    }
    return lookup;
}

function lookupToQuery(lookup) {
    var params= [];
    for (var name in lookup)
        for (var i= 0; i<lookup[name].length; i++)
            params.push(encodeURIComponent(name)+'='+encodeURIComponent(lookup[name][i]));
    return params.length===0? '' : '?'+params.join('&');
}

这使得使用变得简单:

var lookup= queryToLookup(location.search);
lookup['gbn_keywords']= ['coffee & tea'];
var query= lookupToQuery(lookup);

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