You can edit this page using wiki syntax for markup.

Article contents:== Ajax tips Some tips related to the use of the [[/eggref/4/ajax|ajax]] egg. The tips below require consider you have the following eggs (and its dependencies) installed: * spiffy * spiffy-utils * web-scheme * ajax (obviously) === Infrastructure Let's create a basic infrastructure. First, we need a directory to be used by the web server. This directory will hold our web documents. Let's use the default one for spiffy (called {{web}}). prompt> mkdir web Our web-server script ({{web-server.scm}}) is very simple: (use spiffy spiffy-utils web-scheme web-scheme-handler ajax) (spiffy-file-ext-handlers `(("ws" . ,web-scheme-handler))) (spiffy-debug-mode #t) (start-server) You should place this script at the same directory where the {{web}} directory can be found: $ ls -l total 4 drwxr-xr-x 2 mario mario 48 Aug 21 15:08 web -rw-r--r-- 1 mario mario 159 Aug 21 15:08 web-server.scm Make sure the {{prototype.js}} file is under the {{web}} directory, otherwise the examples '''won't work'''! === Testing the infrastructure Save an {{index.ws}} file under the {{web}} directory with the following contents: (ws:page (string-append (span 'id "result") (remote-link "click me" (lambda () (print "hello ")) insert-after: "result")) additional-headers: (ajax)) If this example works, you should see a {{hello}} being printed when you click {{click me}}. This test also serves as a first basic example. {{:-)}} === Basics In the example you can see code from the [[web-scheme]] egg and from the [[/eggref/4/ajax|ajax]] egg. The {{ws:page}} procedure just generates some boring HTML code (HTML, BODY, DOCTYPE...). The keyword argument {{additional-headers}} expects code to be inserted in the HEAD section of the HTML document. The {{ajax}} procedure generates the "link" to the {{prototype.js}} file, which actually provides the ajax functionalities. If invoked without arguments, the {{ajax}} procedure generates HTML code considering that the {{prototype.js}} is located at the root directory of the web server. If you want to place {{prototype.js}} on another location, you === Examples ==== remote-link todo ==== remote-url todo ==== remote action todo === How the ajax egg works The ajax egg uses some special features from the http-server (from the [[http]] egg, used by [[spiffy]]). The http-server has things called ''resources'', which permit binding certain resources (e.g., a pathname from an URL) to a Scheme procedure which is executed on the server side. This is done by the {{http:add-resource}} procedure. What the ajax egg does behind the scenes is to generate javascript code to be executed by the client (web browser), and to register Scheme code to be executed by the server. The generated javascript code references resources created by the ajax egg's procedures (e.g., {{remote-link}}, {{remote-url}}) and the resources are bound to Scheme procedures. The code (remote-link "click me" (lambda () (print "hello ")) insert-after: "result")) showed in the first example, generates the following HTML/javascript code <a href='#' onclick="new Ajax.Updater('result', '/698b8ce1989caea1958dda2c0b10944f', { insertion: Insertion.After });">click me</a> As you can see, the second argument to the {{Ajax.Updater}} constructor is the http-server resource ({{/698b8ce1989caea1958dda2c0b10944f}}, which will be bound to the Scheme procedure passed as the second argument to {{remote-link}}. The resource is an {{md5:digest}} of some values which, when put together, are supposed to generate an unique identifier. Description of your changes:

I would like to authenticate

Spam control

What do you get when you subtract 24 from 11?