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So I have the code below that pulls a 'parameter' from the URL and replaces an ID called 'demo' in my HTML: EXAMPLE: sample.com?demo=test

function getUrlParameter(sParam) { 
    var sPageURL = window.location.search.substring(1); 
    var sURLVariables = sPageURL.split('&'); 
    for (var i = 0; i < sURLVariables.length; i++) { 
        var sParameterName = sURLVariables[i].split('='); 
        if (sParameterName[0] == sParam) { 
            return sParameterName[1]; 
        } 
    } 
}
var demo = decodeURIComponent(getUrlParameter('demo')); 
document.getElementById('demo').innerHTML = demo;

Then I have the following code which does the same, except it pulls from a cookie

function getCookie(c_name) { 
    if (document.cookie.length>0) { 
        c_start=document.cookie.indexOf(c_name + "="); 
        if (c_start!=-1) { 
            c_start=c_start + c_name.length+1; 
            c_end=document.cookie.indexOf(";",c_start); 
            if (c_end==-1) 
                c_end=document.cookie.length; 
            var cookieContent = "Welcome back " + unescape(document.cookie.substring(c_start,c_end)); 
            document.getElementById('demo').innerHTML = cookieContent; 
        } 
    } 
} 
getCookie('demo');

What I'd like to do is write something that pulls from the parameter immediately, and if a user comes back to the page without the URL parameter, pull from the cookie. I'm thinking this is some sort of IF statement. But I'm confused on how to mesh these two scripts together to work in sync.

So essentially, IF demo is in URL, insert into any ID that = demo, if not, look in cookie. It would also be great if I could add spaces to the parameter. So if the URL: sample.com?demo=this+is+a+test To have the ID = this is a test

I've figured this out for the most part. BUT, all ID's called 'demo' become 'undefined' within my HTML document. My HTML looks like this: Welcome New User

So I'd like it to display 'New User' or whatever is displayed in the ID IF there is no parameter or cookie set. Hope this makes sense.

user2736892
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1 Answers1

0

Take out the innerHTML assignment in getCookie, and have it simply return cookieContent when it finds the requested cookie. Then you can test the return values of the functions.

var demo = getUrlParameter('demo') || getCookie('demo');
if (demo) {
    document.getElementById('demo').innerHTML = demo;
}
Barmar
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  • Awesome, thanks! I'm noticing that my spans in my content show up as 'undefined' since its classified in the script above. I don't want the text to show undefined if a user strips the URL. How can I avoid this? A uniquely identifiable element. So I'd like the text to display that ' A uniquely identifiable element.' unless its declared in the URL or cookie. Hope that makes sense. – user2736892 May 05 '16 at 04:32
  • Also, if my parameter is: demo=this+is+a+test how can I turn those +'s into spaces within my content/text? I can't have + within my content. Would love to find out how to do this. Appreciate the help. Have a good day! – user2736892 May 05 '16 at 07:56
  • It shouldn't show up as `undefined`, because the `if()` should skip the `innerHTML` assignment in that case. Unless you're putting the literal string `"undefined" into the cookie. – Barmar May 05 '16 at 15:16
  • You can use `decodeURIComponent` to convert a URL component like `foo+bar` into `foo bar` – Barmar May 05 '16 at 15:17
  • Thanks :) How does this look? var demo = decodeURIComponent(getUrlParameter('demo').replace(/‌​\+/g, " ")); – user2736892 May 05 '16 at 17:22