oxy_indexof() Function
      
      The oxy_indexof() function has two signatures:
         
- 
               
               oxy_indexof( text , toFind)Returns the index within text string of the first occurrence of the toFind substring. - text
- Text to search in.
- toFind
- The searched substring.
 
- 
               
               oxy_indexof( text , toFind , fromOffset )Returns the index within text string of the first occurrence of the toFind substring. The search starts from fromOffset index. - text
- Text to search in.
- toFind
- The searched substring.
- fromOffset
- The index to start the search from.
 
oxy_indexof('abcd', 'bc') returns 1.
            
oxy_indexof('abcdbc', 'bc', 2) returns 4.
            
If we only want to display part of an attribute value, the part that comes before an Appendix string:
image[longdesc]{
 content: oxy_substring(attr(longdesc), 0, 
          oxy_indexof(attr(longdesc), "Appendix"));
}
            
         