Recommendations for AJAH Library

Question

I have a classic ASP application

I would like to add some AJAX-style partial page updates to avoid server roundtrip. For example, list of rows displayed, option to add another in-situ, save it, and table redisplayed / add another.

I don't think I need all the other baggage of the well known AJAX libraries

I would appreciate suggestions for AJAH libraries, and also opinions on whether you think I am daft only adopting AJAH rather than full blown AJAX.

(My application has a template rendering function, so I can already convert database data into "rich HTML", so I perceive that my easiest route is to reuse this and send replacement HTML, using AJAH, to be injected into the page using innerHTML replace)

Thanks

Answer 1

AJAH? There is to my knowledge no such thing as AJAH. Does the H stand for HTML instead of XML? If so, let me disabuse you of the notion that AJAX entails XML. That may have been its inception but that is not the case (now at least). In the moern vernacular Ajax has come to mean pages making Javascript calls back to the server without refreshing the page. Data can be sent to the server and the data returned can be JSON, XML, HTML or whatever you like really. JSON and HTML are probably the most common (with XML next).

As for what API to use. It sounds like you want to spruce up an existing application and (imho) there is no better library for this than jQuery. Its as lightweight as you want with plugins for almost everything and helps you a lot with cross-browser issues. You can easily do things like:

<input id="refresh" type="button" value="Refresh">
...
$("#refresh").click(function() {
  $.ajax({
    url: '/getusers',
    type: "GET",
    timeout: 5000,
    dataType: "html",
    failure: function() {
      alert("An error occurred.");
    },
    success: function(data) {
      $("#userlist").html(data);
    }
  });
});

Answer 2

Link to a quick explanation of the AJAH pattern here: "Asynchronous JavaScript and HTML (Ajah) is a pattern whereby you pass back fully rendered HTML responses rather than XML or JSON formats".

It does appear to blur the lines between the model and the view part of your application (a big sin if you are a MVC purist!), but it sounds like it will produce working software..

IMHO the overhead of a good javascript library (like jQuery) is not that big either, and you usually end up needing one anyway.

Answer 3

i hate to be a purist; but i think that once you start to use AJAX, it's far better to let the JS code to do most of the formatting. for your example (tables), i'd use a templating plugin for jQuery. these let you include a static HTML template in the page, and fill it with the data returned by the AJAX queries.

OTOH, if you really want to do the formatting in the server, simply use the .load() method in jQuery to fetch HTML and insert into any DOM object.