Ajax Expansion 02

1. jquery Plugin
There are many defined methods in the jquery we use that can implement our great majority of functions, but it does not mean that all of the functionality we need to complete can be implemented using jquery, and we can customize a jquery plugin to implement special features in our own projects.
1.1 JQuery Plugin Creation
jquery has already foreseen that we need to create our own plug-ins, as well as a way to create plug-ins, and write the functions that need to be created in parentheses in $.fn.extend (). It is recommended to write an object so that you can use the. method to invoke the method.
1.2 The use of jquery plugins
Since the jquery plugin is jquery-based, jquery must be called before calling the jquery plugin, or there will be an error.
2. Homology and cross-domain
2.1 IFrame Tags
This is a frameset tag that can be used to embed another page in one page content. You can get the IFRAME tag element and then get to the element content in another page.
When you embed another page, you can get to the element in that page, this time a special situation occurs, that is, when the user enters information in the internal nested page, the external page may also get the information that the user entered, and the disclosure of such personal information will harm the user's account security.
2.2 External network cross-domain
Under normal circumstances, the browser does not support cross-domain request data, because of the information security of the server.
However, when the company develops the project, it is often necessary to request some data from the company's other servers, and all of us can also use an unofficial feature, which is to set the data type to JSONP when requesting the message, so that cross-domain requests can occur if the requested server also sets the same type of attribute.

Ajax Expansion 02