Getting multiple query parameters in the s.util.getQueryparam

Never mind. It worked!!

I used this:

s.campaign = s.Util.getQueryParam('cmpid')+":"+s.Util.getQueryParam('source')+":"+s.Util.getQueryParam ('medium');

I set this up in my main library management code.

But for any page (without Query parameters), s.campaign value is now showing ":::". How do I modify the code to not capture any value when the parameters are not present?

s.campaign  = [s.Util.getQueryParam('cmpid'),s.Util.getQueryParam('source'),s.Util.getQueryParam ('medium')].join(":").replace(/::/,'');

Thank you!

The same logic is not working for the below:

s.campaign=[s.Util.getQueryParam('source'),s.Util.getQueryParam('cmpid')].join("-").replace(/-/,'');

the value is being generated as sourcecmpid (without the dash). Any suggestions on modifying it?

I think you might be missing a couple foundational concepts.  Let's tear this thing apart and look at each part.

s.campaign  = [s.Util.getQueryParam('cmpid'),s.Util.getQueryParam('source'),s.Util.getQueryParam ('medium')].join(":").replace(/::/,'');

The first thing to understand is that there is a pipeline of activity, meaning that one operation feeds the one to the right which in turn feeds the next. Below I break it apart into three different lines of code:

s.campaign  = [s.Util.getQueryParam('cmpid'),s.Util.getQueryParam('source'),s.Util.getQueryParam ('medium')];
s.campaign = s.campaign.join(":");
s.campaign = s.campaign.replace(/::/,'');

Let's look at each line:

// Line 1 - This line creates a javascript Array from the values returned by three function calls. 
s.campaign  = [s.Util.getQueryParam('cmpid'),s.Util.getQueryParam('source'),s.Util.getQueryParam ('medium')];

Let's decompose this line even more:

Now let's see it in action:

If our URL is http://www.foo.com/some/path?source=Apples&medium=Oranges&cmpid=Bananas

If we ran just the code above, we'd end up with the array, ["Bananas", "Apples", "Oranges"]

If our URL is http://www.foo.com/some/path?cmpid=Bananas

If we ran just the code above, we'd end up with the array, ["Bananas", "", ""]

If our URL is http://www.foo.com/some/path?name=Martha&age=32

If we ran just the code above, we'd end up with the array, ["", "", ""]

Two notes on the above:  First, note that the order of the parameters in the URL's query string does not matter. They are put into the array in a set order.  Second, note that if a query parameter does not exist, we put an empty string into the array.

Now for line 2:

This takes the array from the prior step and concatenates all of its parts into a string using the delimiter that we passed in.

Here are the examples from above:

Finally, line 3:

This line looks for specific patterns in a string and replaces that pattern with an empty string.   Essentially, find all instances of "::" and remove them.

Here are the examples from above:

Q.E.D

Now I leave it to you.  Armed with this new understanding can you answer your own question?

If not, DM me and I will give you the solution.

-Stew

Hi Stew,

Thank you so much for the great explanation! I really appreciate this to help me understand the fundamentals.

I think the code below for the URL first joins the query parameters with "-" and then applies the replace logic to show the value without the delimiter. Hence, I was seeing the values just sourcecmpid instead of source-cmpid.

s.campaign=[s.Util.getQueryParam('source'),s.Util.getQueryParam('cmpid')].join("-").replace(/-/,'');

However, with the code below, it will join the two parameters with the delimiter as source-cmpid and if the value is empty, it will return with just "-" for s.campaign:

s.campaign=[s.Util.getQueryParam('source'),s.Util.getQueryParam('cmpid')].join("-")

Now, I have to write a logic to replace "-" when there is no query parameter to return an empty string as below:

s.campaign=[s.Util.getQueryParam('source'),s.Util.getQueryParam('cmpid').join("-")].replace(/-/,'');

Did I get it right?

You make a good point. And, yes, you're on track.

I noticed a couple of things while thinking about your answer. Try the following replace logic.

["a","b"].join("-").replace(/(^-)|(-$)/g,'') --> "a-b"

["","b"].join("-").replace(/(^-)|(-$)/g,'') --> "b"

["a",""].join("-").replace(/(^-)|(-$)/g,'') --> "a"

["",""].join("-").replace(/(^-)|(-$)/g,'') --> ""

s.campaign=[s.Util.getQueryParam('source'),s.Util.getQueryParam('cmpid')].join("-").replace(/(^-)|(-$)/g,'');

Note that the solution changes slightly if you have 3 or more items in the array.

Thank you! This does work - and now I understand why the logic would differ based on the number of query parameters.

Appreciate your help!!