Last modified on 29 July 2009, at 15:27

XQuery/XHTML + Voice

MotivationEdit

You want to have your browser read Twitter updates using a text-to-speech conversion extension that is built into your browser.

MethodEdit

XHTML + Voice is supported by the Opera Browser with the Voice extension installed. In this simple application it is used as a browser-based Text-to-Speech engine.

Twitter RadioEdit

This script creates a simple text-to-speech version of Twitter Search.

Obama

LimitationsEdit

  • Window has to be active for the T2S to play on refresh
  • The cleaned text to speak is held in a div which is rendered as white on white text. Initially it was output as a block in the header but it did not seen possible to apply styles. Applying a style display:none hid the text from the T2S engine as well!
  • Transforming the atom content to a a string suitable to speak needs more work.
  • Retweets and similar tweets could be removed using levenstein
  • Male and female voices are assigned randomly by tweet. I'd like to cache the voice assigned to a tweeter so that tweets are consistently spoken in the same voice
  • The initial load doesn't seem to trigger playing, hence the play button, but this also re-fetches the page.
  • This is an ideal situation to use AJAX instead of refresh
  • The T2S engine is quite good at rendering the text but it needs be helped in places, for example by replacing texting abbreviations with their expanded form.
declare namespace atom = "http://www.w3.org/2005/Atom";
 
declare variable $n := xs:integer( request:get-parameter("n",6));
declare variable $search := request:get-parameter("search","");
declare variable $timestamp := request:get-parameter("timestamp",());
declare variable $seconds := $n * 12;
declare variable $noise :=
(  "<b>",
    "</b>",
    "&lt;.+?&gt;",
    "http://[^ ]+",
    "#\w+",
    "RT *@\w+",
    "@\w+",
    "[\[\]\\=«»:;()_?!~\|]",
    '"',
    "\.\.+"
);
 
declare function local:clean ($talk as xs:string, $noise as xs:string*) as xs:string {
    if (empty($noise))
    then $talk
    else
        local:clean(replace($talk,string($noise[1])," "),subsequence($noise,2))
};
 
declare function local:clean($talk as xs:string) as xs:string {
   local:clean($talk,$noise)
};
 
declare option exist:serialize  "method=xhtml media-type=application/xv+xml";
 
let $entries := doc(concat("http://search.twitter.com/search.atom?lang=en&amp;q=",encode-for-uri($search)))//atom:entry
let $entries := if (exists($timestamp))
                          then  $entries[atom:published>$timestamp]
                          else $entries
let $entries := $entries[position() <= $n] 
let $newtimestamp :=  if (exists($entries)) then string($entries[1]/atom:published) else $timestamp
let $entries := reverse($entries)
return
<html xmlns="http://www.w3.org/1999/xhtml" 
      xmlns:vxml="http://www.w3.org/2001/vxml" 
      xmlns:xv="http://www.voicexml.org/2002/xhtml+voice"
      xmlns:ev="http://www.w3.org/2001/xml-events" 
>
   <head>
       <meta http-equiv="refresh" content="{$seconds};url=?search={encode-for-uri($search)}&amp;timestamp={$newtimestamp}&amp;n={$n}"/>
       <title>Tweets matching {$search}</title>
       <vxml:form id="say">
            <vxml:block>
               <vxml:prompt src="#news"/>
         </vxml:block>
        </vxml:form>
      <link rel="stylesheet" type="text/css" href="voice2.css" title="Normal"/>
   </head>
   <body ev:event="load"  ev:handler="#say" >
       <h1>Twitter radio, listening to tweets matching {$search}</h1>
       <form method="get" >
           Listen for <input type="text" name="search" value="{$search}" />
           Max items <input type="text" name="n" value="{$n}" size="4" /> 
           <input type="submit" value="Tune"/>
           <button ev:event="click" ev:handler="#say">Play</button>
       </form>  
       {for $entry in $entries
            return 
                <div>                  
                     <a href="{$entry/atom:author/atom:uri}">{substring-before($entry/atom:author/atom:name, "(")}</a> &#160;
                     {util:parse(concat("<span xmlns='http://www.w3.org/1999/xhtml' >",$entry/atom:content/(text(),*),"</span>"))}
                 </div>
       }    
       <div id="news">
              {for $entry in $entries
                return 
                    <p class='{if (math:random ()< 0.5) then "male" else "female"}'> 
                        { local:clean($entry/atom:content/text())}         
                    </p>
             }     
       </div>
   </body>
</html>

With the style sheet:

.male {
    voice-family: male;
    pause-after:1.5s;
}
.female {
    voice-family:female;
     pause-after:1s
}
#news {
    color:white;
    background-color:white
}