1. INFO 344 Web Tools And Development
CK Wang
University of Washington
Spring 2014

2. Cross Domain Scripting
Simple PHP script, 3 lines of code
It works!
Download html file, run locally (different domain) doesn’t work 
Browser blocks cross domain AJAX

3. Why? Security!! If we allowed cross domain scripting Imagine
Go to
Download their html files
Host those files on
Get users to login!
AND now I can do anything with their data & account!

4. JSONP JSON with Padding Use <script> tag
Pass a call back function
<script> will have function(data)

5. JSONP Open Visual Studio, C# Web Application, Empty
Add new ASMX web service
Implement WebMethod for getOneLessThanN(int n)
Add http get/post to web.config
Uncomment script services & add script method/response format = JSON, need to clear context to remove meta data
Publish on Azure! (as a web site)

6. JSONP
Create jsonp.html, add <script> to your service, for example:
updateResults is your callback
<script> to your service will generate javascript that calsl your callback function

7. JSONP Part 2! Write a version using jQuery.
Part 3:
How would you write your own JSONP wrapper? i.e. implement this ajax jsonp call?

8. Reading

9. Questions?