To help understand translation, look at a translator that is written entirely in JavaScript, which does not rely on a C library for any functionality. The following translator example would be more efficient if it were written in C, but the JavaScript version is simpler, which makes it perfect for demonstrating how translators work.

As with most translators, this one is designed to mimic server behavior. Assume that your web server is configured to replace the KENT tag with a different picture of an engineer, depending on the day of the week, the time of day, and the user’s platform. The translator does the same thing, only locally.

Create the block/tag translator

  1. Create a new blank file.

  2. Enter the following code:

     <html> 
    <head> 
    <title>Kent Tag Translator</title> 
    <meta http-equiv="Content-Type" content="text/html; charset="> 
    <script language="JavaScript"> 
     /********************************************************** 
     * The getTranslatorInfo() function provides information  * 
     * about the translator, including its class and name,    * 
     * the types of documents that are likely to contain the  * 
     * markup to be translated, the regular expressions that  * 
     * a document containing the markup to be translated      * 
     * would match (whether the translator should run on all  * 
     * files, no files, in files with the specified           * 
     * extensions, or in files matching the specified         * 
     * expressions).                                          * 
     **********************************************************/ 
    function getTranslatorInfo(){ 
        //Create a new array with 6 slots in it 
        returnArray = new Array(6); 
         
        returnArray[0] = "DREAMWEAVER_TEAM";           // The translatorClass 
        returnArray[1] = "Kent Tags";                  // The title 
        returnArray[2] = "0";                          // The number of extensions 
        returnArray[3] = "1";                          // The number of expressions 
        returnArray[4] = "<kent";                      // Expression 
        returnArray[5] = "byExpression";               // run if the file contains "<kent" 
        return returnArray; 
    } 
         
    /************************************************************************** 
     * The translateMarkup() function performs the actual translation.        * 
     * In this translator, the translateMarkup() function is written          * 
     * entirely in JavaScript (that is, it does not rely on a C library) --   * 
     * and it's also extremely inefficient. It's a simple example, however,   * 
     * which is good for learning.                                            * 
    ***************************************************************************/ 
    function translateMarkup(docNameStr, siteRootStr, inStr){ 
        var outStr = "";                      // The string to be returned after translation 
        var start = inStr.indexOf('<kent>');  // The first position of the KENT tag 
                                              // in the document. 
        var replCode = replaceKentTag();      // Calls the replaceKentTag() function 
                                              // to get the code that will replace KENT. 
            var outStr = "";                  // The string to be returned after translation 
         //If the document does not contain any content, terminate the translation. 
        if ( inStr.length <= 0 ){ 
             return ""; 
        } 
         
        // As long as start, which is equal to the location in inStr of the 
        // KENT tag, is not equal to -1 (that is, as long as there is another 
        // KENT tag in the document) 
        while (start != -1){ 
             // Copy everything up to the start of the KENT tag. 
             // This is very important, as translators should never change 
             // anything other than the markup that is to be translated. 
             outStr = inStr.substring(0, start); 
             // Replace the KENT tag with the translated HTML, wrapped in special 
             // locking tags. For more information on the repacement operation, see 
             // the comments in the replaceKentTag() function. 
             outStr = outStr + replCode; 
     
             // Copy everything after the KENT tag. 
             outStr = outStr + inStr.substring(start+6); 
     
             // Use the string you just created for the next trip through 
             // the document. This is the most inefficient part of all. 
             inStr = outStr; 
             start = inStr.indexOf('<kent>'); 
     
        } 
        // When there are no more KENT tags in the document, return outStr. 
        return outStr; 
    } 
     
    /************************************************************** 
    * The replaceKentTag() function assembles the HTML that will  * 
    * replace the KENT tag and the special locking tags that will * 
    * surround the HTML. It calls the getImage() function to      * 
    * determine the SRC of the IMG tag.                           * 
    **************************************************************/ 
    function replaceKentTag(){ 
        // The image to display. 
        var image = getImage();     
        // The location of the image on the local disk. 
        var depFiles = dreamweaver.getSiteRoot() + image; 
        // The IMG tag that will be inserted between the lock tags.     
        var imgTag = '<IMG SRC="/' + image + '" WIDTH="320" HEIGHT="240" ALT="Kent">\n'; 
        // 1st part of the opening lock tag. The remainder of the tag is assembled 
        below. 
        var start = '<MM:BeginLock translatorClass="DREAMWEAVER_TEAM" type="kent"'; 
        // The closing lock tag. 
        var end = '<MM:EndLock>'; 
             
        //Assemble the lock tags and the replacement HTML. 
        var replCode = start + ' depFiles="' + depFiles + '"'; 
        replCode = replCode + ' orig="%3Ckent%3E">\n'; 
        replCode = replCode + imgTag; 
        replCode = replCode + end; 
         
        return replCode; 
    } 
     
    /****************************************************************** 
     * The getImage() function determines which image to display      * 
     * based on the day of the week, the time of day and the          * 
     * user's platform. The day and time are figured based on UTC     * 
     * time (Greenwich Mean Time) minus 8 hours, which gives          * 
     * Pacific Standard Time (PST). No allowance is made for Daylight * 
     * Savings Time in this routine.                                  * 
    ******************************************************************/ 
    function getImage(){ 
        var today = new Date();                  // Today's date & time. 
        var day = today.getUTCDay();             // Day of the week in the GMT time zone. 
                                                 // 0=Sunday, 1=Monday, and so on. 
            var hour = today.getUTCHours();     // The current hour in GMT, based on the 
                                                // 24-hour clock. 
        var SFhour = hour - 8;                  // The time in San Francisco, based on the 
                                                // 24-hour clock. 
        var platform = navigator.platform;      // User's platform. All Windows computers 
                                                // are identified by Dreamweaver as "Win32", 
                                                // all Macs as "MacPPC". 
            var imageRef;                       // The image reference to be returned. 
                // If SFhour is negative, you have two adjustments to make. 
                // First, subtract one from the day count because it is already the wee 
                // hours of the next day in GMT. Second, add SFhour to 24 to 
                // give a valid hour in the 24-hour clock. 
         if (SFhour < 0){ 
             day = day - 1; 
                 // The day count back one would make it negative, and it's Saturday, 
                 // so set the count to 6. 
                 if (day < 0){ 
                         day = 6; 
                 } 
             SFhour = SFhour + 24; 
         } 
         
        // Now determine which photo to show based on whether it's a work day or a 
        // weekend; what time it is; and, if it's a time and day when Kent is 
        // working, what platform the user is on. 
         
        //If it's not Sunday 
        if (day != 0){ 
             //And it's between 10am and noon, inclusive 
             if (SFhour >= 10 && SFhour <= 12){ 
                    imageRef = "images/kent_tiredAndIrritated.jpg"; 
                //Or else it's between 1pm and 3pm, inclusive 
             }else if (SFhour >= 13 && SFhour <= 15){ 
                    imageRef =    "images/kent_hungry.jpg"; 
             //Or else it's between 4pm and 5pm, inclusive 
             }else if (SFhour >= 16 && SFhour <= 17){ 
                    //If user is on Mac, show Kent working on Mac 
                    if (platform == "MacPPC"){ 
                         imageRef = "images/kent_gettingStartedOnMac.jpg"; 
                    //If user is on Win, show Kent working on Win 
                    }else{ 
                         imageRef = "images/kent_gettingStartedOnWin.jpg"; 
                    } 
             //Or else it's after 6pm but before the stroke of midnight 
             }else if (SFhour >= 18){ 
                     //If it's Saturday 
                     if (day == 6){ 
                         imageRef = "images/kent_dancing.jpg"; 
                    //If it's not Saturday, check the user's platform 
                    }else if (platform == "MacPPC"){ 
                         imageRef = "images/kent_hardAtWorkOnMac.jpg"; 
                    }else{ 
                         imageRef = "images/kent_hardAtWorkOnWin.jpg"; 
                    } 
             }else{ 
                    imageRef = "images/kent_sleeping.jpg"; 
             } 
        //If it's after midnight and before 10am, or anytime on Sunday 
        }else{ 
             imageRef = "images/kent_sleeping.jpg"; 
        } 
         
        return imageRef; 
    } 
     
    </script> 
    </head> 
     
    <body> 
    </body> 
    </html>
  3. Save the file as kent.htm in the Configuration/Translators folder.

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