Csdrhrt

I want to get community base url in my lightning component without apex. Right now I am using the design component to store the value but that is not optimal as I have multiple page references and typing each of them in the community builder is really hard and error prone.

Yes, you can retrieve the current page url in your JavaScript controller. And set the value of attribute in your component for later use according to your requirement.

Component

 <aura:attribute name="cbaseURL" type="String"/>

JS Controller

 var urlString = window.location.href;

 var baseURL = urlString.substring(0, urlString.indexOf("/s"));

 component.set("v.cbaseURL", baseURL);

Hope this helps.

EDIT:

As RedDevil highlighted that using window.location can create issues with Microsoft browsers. I tend to search a bit and find out interesting result. So I'd like to all the readers must go through this stackoverflow link to read about the details and use whatever suits you best.

However the widely accepted answer says:

document.location is a synonym for window.location that has been
deprecated for almost as long as JavaScript has existed. Don't use it.

location is a structured object, with properties corresponding to the
parts of the URL. location.href is the whole URL in a single string.
Assigning a string to either is defined to cause the same kind of
navigation, so take your pick.

I consider writing to location.href = something to be marginally
better as it's slightly more explicit about what it's doing. You
generally want to avoid just location = something as it looks
misleadingly like a variable assignment. window.location = something
is fine though.