Summary of the drop-down menu function implemented by the php framework and ajax

In Web development, the drop-down menu is composed of several main menu items displayed on the top of the window and sub-menus under each menu bar. Each sub-menu usually contains several sub-menu items. Generally, the sub-menu of a menu bar is displayed only when the mouse pointer points to the menu bar. In development, the use of php and php frameworks to implement drop-down menus or navigation menus is still challenging. In general, apart from using background languages, some front-end technologies will also be used together. When the drop-down menu changes, the event is triggered and then sent to the php background through ajax technology for data processing. The following article describes how to use the php framework and ajax technologies to implement the drop-down menu function.

1. First, you can learn about the relevant content in the implementation tutorial of various drop-down menus.

Let's talk about the following ideas:

(1) when the user selects a province, the event is triggered, and the id of the current province is sent to the server program through ajax.

(2) for example, if the China region is used and the China region is 0001, the China region is 0001;

(3) the server queries the database based on client requests and returns the database to the client in a certain format.

2. ThinkPHP + Ajax implement two-level linkage drop-down menu

Ajax code is triggered after the first layer type change. The main parameters of the ajax method include:

1) url: the address for receiving ajax requests from the background;

2) data: the data uploaded to the background is generally transmitted in json format. here, the id value of the selected class is passed.

3) type: transfer methods, including get and post methods. I usually use post. The data that can be transmitted is more secure than get;

4) error: Method for ajax execution failure;

5) success: the method for successful ajax execution, that is, the callback function. When executing success, I first cleared the content of the second drop-down menu with empty () and then output the data obtained from the background.

Q & A related to the drop-down menu function implemented by php, php framework, and ajax

1. drop-down menu click event

2. how to obtain background data through ajax after selecting from the drop-down menu without refreshing the page

3. how to implement the thinkphp drop-down menu items based on the parameters transmitted by assign by default?