Js implements the countdown function after the verification code is sent

Js implements the countdown function after the verification code is sent

Previously I shared the countdown function with only js. Later I tested the function and found that the countdown was unavailable after the page was refreshed or closed. I did not find a suitable solution on the Internet, so I wrote it myself. This is an optimized version. After the page is refreshed or re-opened, the countdown will still work.

Note:

The cookie was initially created for 60 seconds. that is to say, if you close the webpage when the countdown is 20. if you open the page after 20 seconds, there will be no countdown display. However, if the countdown is 20, the page will be closed. If you open the page again within 20 seconds, there will be a countdown display.

Html code

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1	<Input id = "second" type = "button" value = "get verification code for free"/>

Js operations on cookies

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// Add a cookie when sending the verification code Function addCookie (name, value, expiresHours ){ Var cookieString = name + "=" + escape (value ); // Determine whether to set the expiration time. 0 indicates that the browser is disabled. If (expiresHours> 0 ){ Var date = new Date (); Date. setTime (date. getTime () + expiresHours * 1000 ); CookieString = cookieString + "; expires =" + date. toUTCString (); } Document. cookie = cookieString; } // Modify the cookie value Function editCookie (name, value, expiresHours ){ Var cookieString = name + "=" + escape (value ); If (expiresHours> 0 ){ Var date = new Date (); Date. setTime (date. getTime () + expiresHours * 1000); // The unit is milliseconds. CookieString = cookieString + "; expires =" + date. toGMTString (); } Document. cookie = cookieString; } // Obtain the cookie value based on the name Function getCookieValue (name ){ Var strCookie = document. cookie; Var arrCookie = strCookie. split (";"); For (var I = 0; I <arrCookie. length; I ++ ){ Var arr = arrCookie [I]. split ("= "); If (arr [0] = name ){ Return unescape (arr [1]); Break; } Else { Return ""; Break; } }   }

Main logic code

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$ (Function (){ $ ("# Second"). click (function (){ SendCode ($ ("# second ")); }); V = getCookieValue ("secondsremained"); // obtain the cookie value If (v> 0 ){ Settime ($ ("# second"); // start countdown } }) // Send the verification code Function sendCode (obj ){ Var phonenum = $ ("# phonenum"). val (); Var result = isPhoneNum (); If (result ){ DoPostBack ('$ {base}/login/getcode.htm', backFunc1, {"phonenum": phonenum }); AddCookie ("secondsremained", 60, 60); // Add cookie record, valid for 60 s Settime (obj); // start countdown } } // Use ajax to submit a text message interface to the background. Function doPostBack (url, backFunc, queryParam ){ $. Ajax ({ Async: false, Cache: false, Type: 'post ', Url: url, // the requested action path Data: queryParam, Error: function () {// processing function for request failure }, Success: backFunc }); } Function backFunc1 (data ){ Var d = $. parseJSON (data ); If (! D. success ){ Alert (d. msg ); } Else {// return the verification code Alert ("Simulated Verification Code:" + d. msg ); $ ("# Code"). val (d. msg ); } } // Start countdown Var countdown; Function settime (obj ){ Countdown = getCookieValue ("secondsremained "); If (countdown = 0 ){ Obj. removeAttr ("disabled "); Obj. val ("Get verification code for free "); Return; } Else { Obj. attr ("disabled", true ); Obj. val ("resend (" + countdown + ")"); Countdown --; EditCookie ("secondsremained", countdown, countdown + 1 ); } SetTimeout (function () {settime (obj)}, 1000) // run once every 1000 milliseconds } // Verify that the mobile phone number is valid Function isPhoneNum (){ Var phonenum = $ ("# phonenum"). val (); Var myreg =/^ (13 [0-9] {1}) | (15 [0-9] {1 }) | (18 [0-9] {1}) + \ d {8}) $ /; If (! Myreg. test (phonenum )){ Alert ('enter a valid mobile phone number! '); Return false; } Else { Return true; } }

The above is all the content of this article. I hope you will like it.