CSS based on Condition

Question

/* BOC - GRID VIEW */
.ribbongrid {
   position: absolute;
   left: 10px; top: -5px;
   z-index: 1;
   overflow: hidden;
   width: 75px; height: 75px; 
   text-align: right;
}
.ribbongrid span {
   font-size: 10px;
   color: #fff; 
   text-transform: uppercase; 
   text-align: center;
   font-weight: bold; line-height: 20px;
   transform: rotate(-45deg);
   width: 100px; display: block;
   background: #79A70A;
   background: linear-gradient(#9BC90D 0%, #79A70A 100%);
   box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
   position: absolute;
   top: 19px; left: -21px;
}
.ribbongrid span::before {
   content: '';
   position: absolute; 
   left: 0px; top: 100%;
   z-index: -1;
   border-left: 3px solid #79A70A;
   border-right: 3px solid transparent;
   border-bottom: 3px solid transparent;
   border-top: 3px solid #79A70A;
}
.ribbongrid span::after {
   content: '';
   position: absolute; 
   right: 0%; top: 100%;
   z-index: -1;
   border-right: 3px solid #79A70A;
   border-left: 3px solid transparent;
   border-bottom: 3px solid transparent;
   border-top: 3px solid #79A70A;
}
.red span {background: linear-gradient(#F70505 0%, #8F0808 100%);}
.red span::before {border-left-color: #8F0808; border-top-color: #8F0808;}
.red span::after {border-right-color: #8F0808; border-top-color: #8F0808;}

.blue span {background: linear-gradient(#2989d8 0%, #1e5799 100%);}
.blue span::before {border-left-color: #1e5799; border-top-color: #1e5799;}
.blue span::after {border-right-color: #1e5799; border-top-color: #1e5799;}
/* EOC - GRID VIEW */

/* BOC - LIST VIEW */
.ribbonlist {
   position: absolute;
   left: 10px; top: 5px;
   z-index: 1;
   overflow: hidden;
   width: 75px; height: 75px; 
   text-align: right;
}
.ribbonlist span {
   font-size: 10px;
   color: #fff; 
   text-transform: uppercase; 
   text-align: center;
   font-weight: bold; line-height: 20px;
   transform: rotate(-45deg);
   width: 100px; display: block;
   background: #79A70A;
   background: linear-gradient(#9BC90D 0%, #79A70A 100%);
   box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
   position: absolute;
   top: 19px; left: -21px;
}
.ribbonlist span::before {
   content: '';
   position: absolute; 
   left: 0px; top: 100%;
   z-index: -1;
   border-left: 3px solid #79A70A;
   border-right: 3px solid transparent;
   border-bottom: 3px solid transparent;
   border-top: 3px solid #79A70A;
}
.ribbonlist span::after {
   content: '';
   position: absolute; 
   right: 0%; top: 100%;
   z-index: -1;
   border-right: 3px solid #79A70A;
   border-left: 3px solid transparent;
   border-bottom: 3px solid transparent;
   border-top: 3px solid #79A70A;
}
.red span {background: linear-gradient(#F70505 0%, #8F0808 100%);}
.red span::before {border-left-color: #8F0808; border-top-color: #8F0808;}
.red span::after {border-right-color: #8F0808; border-top-color: #8F0808;}

.blue span {background: linear-gradient(#2989d8 0%, #1e5799 100%);}
.blue span::before {border-left-color: #1e5799; border-top-color: #1e5799;}
.blue span::after {border-right-color: #1e5799; border-top-color: #1e5799;}
/* EOC - LIST VIEW */

if (Grid_View = 'True') {
  <div class="ribbongrid blue"><span>Special</span></div>
} else {
  <div class="ribbonlist blue"><span>Special</span></div>
}

The only difference between the two css is changing the height from grid left: 10px; top: -5px; ----------> list left: 10px; top: 5px;

This was just an example. Is there a way of combining the two css just to optimise the code rather copying and pasting several times?

Answer 1

You can achieve it this way:

if (Grid_View = 'True') {
  <div class="ribbongrid blue"><span>Special</span></div>
} else {
  <div class="ribbongrid ribbonlist blue"><span>Special</span></div>
}

and your css:

.ribbongrid {
  position: absolute;
  left: 10px; 
  top: -5px;
  z-index: 1;
  overflow: hidden;
  width: 75px; height: 75px; 
  text-align: right;
}

.ribbongrid.ribbonlist {
  top: 5px;
}

This will override your top from -5px to 5px

Answer 2

Just create two new classes(for changing the height from grid left: 10px; top: -5px; ----------> list left: 10px; top: 5px;) and have a common CSS for everything else. And then use JavaScript to switch between those 2 classes.

FOR EXAMPLE:
The code given by you can be modified like this,

CSS:

/*RIBBON GRID*/
.ribbon_grid {
   left: 10px;
   top: -5px;
}

/*RIBBON LIST*/
.ribbon_list {
   left: 10px;
   top: 5px;
}

/*COMMON CODE FOR BOTH RIBBONS*/
.ribbon {
   position: absolute;
   z-index: 1;
   overflow: hidden;
   width: 75px; height: 75px; 
   text-align: right;
}
.ribbon span {
   font-size: 10px;
   color: #fff; 
   text-transform: uppercase; 
   text-align: center;
   font-weight: bold; line-height: 20px;
   transform: rotate(-45deg);
   width: 100px; display: block;
   background: #79A70A;
   background: linear-gradient(#9BC90D 0%, #79A70A 100%);
   box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
   position: absolute;
   top: 19px; left: -21px;
}
.ribbon span::before {
   content: '';
   position: absolute; 
   left: 0px; top: 100%;
   z-index: -1;
   border-left: 3px solid #79A70A;
   border-right: 3px solid transparent;
   border-bottom: 3px solid transparent;
   border-top: 3px solid #79A70A;
}
.ribbon span::after {
   content: '';
   position: absolute; 
   right: 0%; top: 100%;
   z-index: -1;
   border-right: 3px solid #79A70A;
   border-left: 3px solid transparent;
   border-bottom: 3px solid transparent;
   border-top: 3px solid #79A70A;
}
.red span {background: linear-gradient(#F70505 0%, #8F0808 100%);}
.red span::before {border-left-color: #8F0808; border-top-color: #8F0808;}
.red span::after {border-right-color: #8F0808; border-top-color: #8F0808;}

.blue span {background: linear-gradient(#2989d8 0%, #1e5799 100%);}
.blue span::before {border-left-color: #1e5799; border-top-color: #1e5799;}
.blue span::after {border-right-color: #1e5799; border-top-color: #1e5799;}

JAVASCRIPT:

if (Grid_View = 'True') {
  <div class="ribbon ribbon_grid blue"><span>Special</span></div>
} else {
  <div class="ribbon ribbon_list blue"><span>Special</span></div>
}

Hope this helps :)