Javascript Needed - test if a web page is there or not

Discussion in 'JavaScript' started by SDTEAM, Feb 15, 2006.

0
  1. #1
    Hello, I am looking for a piece of Javascript that will check to see if a web page is available at a particular domain - and if the page is available then to redirect to it, however if the page is not available then redirect to an alternative page at a different domain.

    ...this seems like it should be fairly simple - so if anyone can help I would apreciate it.

    thanks for looking at my post :)
     
    SDTEAM, Feb 15, 2006 IP
  2. Jowan Pasco

    Jowan Pasco Peon

    Messages:
    38
    Likes Received:
    2
    Best Answers:
    0
    Trophy Points:
    0
    #2
    You would probably need some backend support for that. It's basically AJAX. Say, you write a page that takes a url as a parameter, and if that url is valid, outputs something like this:

    <script type="text/javascript">
    window.parent.redirectTo("http://valid.url.here.com");
    </script>

    Then in your main page, you define this:

    function redirectTo(id) {
    location.href = id;
    }

    Then use a hidden iframe to load your backend url, and voila.
     
    Jowan Pasco, Mar 2, 2006 IP
  3. SDTEAM

    SDTEAM Peon

    Messages:
    3
    Likes Received:
    0
    Best Answers:
    0
    Trophy Points:
    0
    #3
    Thank you for your response, and you are right the function to redirect to a url works well, however how do I test to see if I should redirect to the url? (if the webserver is offline the user wont see anything)

    can this be done with javascript?

    for example if the webpage "http://www.asiatic-lion.org/gallery/chester1.html" can be found by the browser then redirect to it, otherwise redirect to "http://bbc.co.uk"
     
    SDTEAM, Mar 9, 2006 IP
  4. Jowan Pasco

    Jowan Pasco Peon

    Messages:
    38
    Likes Received:
    2
    Best Answers:
    0
    Trophy Points:
    0
    #4
    If you want to do this entirely client-side, without backend support, then XMLHttpRequest object might work for you. Check out this tutorial - http:/developer.apple.com/internet/webcontent/xmlhttpreq.html , or google "xmlhttprequest". You'd need a small subset of its functionality - basically just to check if a page is there or not. There is a 'status' attribute, it might work for you.
     
    Jowan Pasco, Mar 9, 2006 IP
    SDTEAM likes this.
  5. marty

    marty Peon

    Messages:
    154
    Likes Received:
    7
    Best Answers:
    0
    Trophy Points:
    0
    #5
    marty, Mar 9, 2006 IP
    SDTEAM likes this.
  6. SDTEAM

    SDTEAM Peon

    Messages:
    3
    Likes Received:
    0
    Best Answers:
    0
    Trophy Points:
    0
    #6
    Thank you both for your help, I may not get a chance to sort this out immediately but the links to "http://www-128.ibm.com/developerworks/java/library/wa-ajaxintro3/index.html" and "http:/developer.apple.com/internet/webcontent/xmlhttpreq.html" look very useful.

    I must admit I had not heard of the "XMLHttpRequest" object, hopefully I can sort out everything over the next few days.... (after the weekend).

    once again thank you, the help is very much apreciated.
     
    SDTEAM, Mar 10, 2006 IP