PHP paging class usage _ PHP Tutorial

The usage of the PHP paging class. In this article, we will introduce in detail the code example of the PHP paging class :? To avoid errors caused by repeated file inclusion, php adds the condition for determining whether a function exists: in this article, we will give you a detailed introduction

PHP paging code example:

1. <? Php
2. // To avoid errors caused by repeated file inclusion,
   Added conditions for determining whether a function exists:
3. If (! Function_exists (pageft )){
4. // Define the pageft () function. The three parameters are described as follows:
5. // $ Totle: total information;
6. // $ Displaypg: number of information displayed on each page. the default value is 20;
7. // $ Url: link in the paging navigation, except for adding different
   The parts outside the "page" of the query information are the same as the URL.
8. // The default value should be the URL of the current page (that is, $ _ SERVER
   ["REQUEST_URI"]), but set the right side of the default value.
   It can only be a constant. Therefore, this default value is set to an empty string and is set to a URL on this page within the function.
9. Function pageft ($ totle, $ displaypg = 20, $ url = ''){
10. // Define several global variables:
11. // $ Page: current page number;
12. // $ Firstcount: (database) The start item of the query;
13. // $ Pagenav: page navigation bar code, which is not output in the function;
14. // $ _ SERVER: required to read the URL "$ _ SERVER [" REQUEST_URI "]" on this page.
15. Global $ page, $ firstcount, $ pagenav, $ _ SERVER;
16. // To enable external function access to "$ displaypg"
    And set it as a global variable. Note that a variable is redefined.
    If it is a global variable, the original value is overwritten, so the value is assigned again here.
17. $ GLOBALS ["displaypg"] = $ displaypg;
18. If (! $ Page) $ page = 1;
19. // If $ url uses the default value, that is, null value, the value is assigned to the URL of the current page:
20. If (! $ Url) {$ url = $ _ SERVER ["REQUEST_URI"];}
21. // URL analysis:
22. $ Parse_urlparse_url = parse_url ($ url );
23. $ Url_query = $ parse_url ["query"]; // Retrieve the query string of the URL separately.
24. If ($ url_query ){
25. // Because the URL may contain page number information,
    We need to remove it to add new page number information.
26. // The regular expression is used here.
27. $ Url_query = ereg_replace ("(^ | &) page = $ page", "", $ url_query );
28. // Replace the query string of the processed URL with the query string of the original URL:
29. $ Url = str_replace ($ parse_url ["query"], $ url_query, $ url );
30. // Add page after the URL to query the information, but the value to be assigned is:
31. If ($ url_query) $ url. = "& page"; else $ url. = "page ";
32. } Else {
33. $ Url. = "? Page ";
34. }
35. // Page number calculation:
36. $ Lastpg = ceil ($ totle/$ displaypg); // The last page, also the total number of pages
37. $ Page = min ($ lastpg, $ page );
38. $ Prepg = $ page-1; // Previous page
39. $ Nextpg = ($ page = $ lastpg? 0: $ page + 1); // Next page
40. $ Firstcount = ($ page-1) * $ displaypg;
41. // Start the paging navigation bar code:
42. $ Pagenav = "display". ($ Totle? ($ Firstcount + 1): 0 )."
    -". Min ($ firstcount + $ displaypg, $ totle )."
    A total of $ totle records
    ";
43. // If there is only one page, the function will jump out:
44. If ($ lastpg<= 1) return false;
45. $ Pagenav. = "<a href = '$ url = 1'> homepage </a> ";
46. If ($ prepg) $ pagenav. = "<a href ='
    $ Url = $ prepg '> Previous Page </a> "; else $ pagenav. =" previous page ";
47. If ($ nextpg) $ pagenav. ="
    <A href = '$ url = $ nextpg'> Next page </a> "; else $ pagenav. =" ";
48. $ Pagenav. = "<a href = '$ url = $ lastpg'> last page </a> ";
49. // Pull-down Jump List, listing all page numbers cyclically:
50. $ Pagenav. = "to the <select name = 'topage'
    Size = '1' onchange = 'window. location = "$ url =" + this. value'>N ";
51. For ($ I = 1; $ I<= $ Lastpg; $ I ++ ){
52. If ($ I = $ page) $ pagenav. = "<
    Option value = '$ I' selected> $ I </option> n ";
53. Else $ pagenav. ="
    $ I </option> n ";
54. }
55. $ Pagenav. = "</select> Page, total $ lastpg page ";
56. }
57. }
58. ?>

The above is the detailed usage of the PHP paging class, and I hope it will help you.

Example code of the pagination class in PHP :? Php // to avoid repeated file inclusion errors, the following conditions are added to determine whether a function exists :...