1 / 5

AJAX Basics

AJAX Basics. xhr = new XMLHttpRequest(); xhr.onreadystatechange = xhrHandler; xhr.open("POST", url); xhr.send(postData); ... function xhrHandler() { if (this.readyState != 4) { return; } if (this.status != 200) { // Handle error ... return; } ...

halia
Télécharger la présentation

AJAX Basics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AJAX Basics xhr = new XMLHttpRequest(); xhr.onreadystatechange = xhrHandler; xhr.open("POST", url); xhr.send(postData); ... function xhrHandler() { if (this.readyState != 4) { return; } if (this.status != 200) { // Handle error ... return; } ... var text = this.responseText; var document = this.responseXML; } State 4 means “done” Response available as raw text or XML CS 142 Lecture Notes: Ajax

  2. JSON Example {name: "Alice", gpa: 3.5, friends: ["Bill", "Carol", "David"]} CS 142 Lecture Notes: Ajax

  3. Name: Al Alfred Wang Alice Washington Allen Williams Allison McLean Alok Chandra Higher-Level AJAX Example <%= form.text_field(:userName) %> ... <div id="completionMenu">...</div> ... <%= observe_field( :form_userName, :update => "completionMenu", :url => {:action => "nameChoices"} ) %> class FooController < ApplicationController def nameChoices prefix = params[:form][:userName] ... compute names ... render :partial => "name_list", :layout => false end

  4. Name: Al Alfred Wang Alice Washington Allen Williams Allison McLean Alok Chandra Higher-Level AJAX Example <%= form.text_field(:userName) %> ... <div id="completionMenu">...</div> ... <%= observe_field( :form_userName, :update => "completionMenu", :url => {:action => "nameChoices"} ) %> class FooController < ApplicationController def nameChoices prefix = params[:form][:userName] ... compute names ... render :partial => "name_list", :layout => false end

  5. CS 142 Lecture Notes: Ajax

More Related