Section led by Ivan Lee Reachable at ivan period lee at cs period stanford period edu 1

- User types a character - Javascript invoked (hint: use a JS class) - Create and set a function that will be called when an HTTP status 200 is returned - Construct a POST url to a specific method of a Rails controller, incorporating any necessary parameters - Send the xmlhttp request 2

- Rails method invoked - Perform any database queries that need to be done server-side - Render a partial – this creates full HTML, which is treated as the xmlhttp response! - What happens if you return a JSON object instead? - Set the innerhtml of the appropriate object 3

 if (window.XMLHttpRequest) { this.xmlhttp = new XMLHttpRequest(); }  this.xmlhttp.onreadystatechange = function()…  this.xmlhttp.open(sMethod, sUrl)  this.xmlhttp.setRequestHeader(sName, sValue)  this.xmlhttp.send(varBody)  this.xmlhttp.responseText 4

 Make sure you think about how to make your classes and AJAX code reusable  Make sure you pass along an authenticity token! (see assignment hints section)  Encode your parameters (see assignment hints section)  Make sure thumbnails redirect to the appropriate link. If the user has a large photo collection, make sure that the selected photo is visible.  No using any other JS frameworks, or built-in Rails Ajax Helpers  Test in Firefox  Validate your HTML 5

 This is the last project! If you want to strut your stuff, this is the time to do it. You have all these tools at your disposal. 6

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