What does the old() method in laravel template do?

Question

What does the old() method in laravel template do?

Answer 1

You can use phpstorm and then command+b to view its source code,

if (! function_exists('old')) {
    /**

• Retrieve an old input item.
  *

• @param string $key

• @param mixed $default

• @return mixed
  */

1. old($key = null, $default = null)

      {
          return app('request')->old($key, $default);
      }

   }

In fact, this also points to request

Answer 2

Can be used to receive old input data returned by the validate object. In this way, users can know what data they filled in before when verification fails.

Answer 3

For example, when posting to an address and verifying data errors, you have to return to the previous page. For a better user experience, the filled-in information will be saved in the flash session and displayed on the previous page.
This way users won’t make mistakes after painstakingly filling in a lot of form data, and then go back and refill it.

Answer 4

Documentation: http://laravel-china.org/docs...

Old input data
When the user fails to submit the form, laravel will automatically flash the user's input data into a one-time session (this data will be lost as soon as it is refreshed, so it is called one-time data). Then old('input_name') can take out the flash memory data in the session, thereby preventing the user from re-entering.

<input type="text" name="input_name" value="{{ old('input_name') }}" />