CFLib.org – Common Function Library Project

Description:
Highlights words in a string that are found in a keyword list. Useful for search result pages.

Return Values:
Returns the string with the keywords highlighted.

Example:

<cfoutput>
<cfset l = "foo">
<cfset s = "foo zfooz foo foo zfoo fooz">
#l#<br />
#s#<br />
#highlightKeywords(s, l)#<br />
<hr />

<cfset l = "foo,bar">
<cfset s = "foo bar zfooz zbarz foo bar foo bar">
#l#<br />
#s#<br />
#highlightKeywords(s, l, {tag="span", attributes='style="color:red;"'})#<br />
<hr />

<cfset s = "fooz bar zfooz zbarz foo bar foo zbar">
#l#<br />
#s#<br />
#highlightKeywords(s, l, {tag="strong"})#<br />
<hr />
</cfoutput>

Parameters:

Full UDF Source:

/**
 * Highlights words in a string that are found in a keyword list.
 * v0.9 by Simon Bingham.
 * v1.0 by Adam Cameron. Improved regex and added configurable highlighting.
 * 
 * @param str      The string to highlight. (Required)
 * @param keywords      The list of keywords to highlight within the string. (Required)
 * @param highlight      A struct containing keys for tag and attributes, These are used to highlight the keyword. Defaults to an EM tag. (Required)
 * @return Returns the string  with the keywords highlighted. 
 * @author Simon Bingham (me@simonbingham.me.uk) 
 * @version 1.0, September 29, 2012 
 */
string function highlightKeywords(required string str, required string keywords, struct highlight){
    var keyword        = "";
    var replacement    = "";
    
    param name="highlight.tag"            default="em";
    param name="highlight.attributes"    default="";
    
    for (var index=1; index <= listLen( arguments.keywords ); index++){
        keyword = listGetAt(arguments.keywords, index);
        replacement = "<#highlight.tag#";
        if (len(highlight.attributes)){
            replacement &= " #highlight.attributes#";
        }
        replacement &= ">" & keyword & "</#highlight.tag#>";

        arguments.str = reReplaceNoCase( arguments.str, "\b#keyword#\b", replacement, "all" );
    }
    return arguments.str;
}