Function exist javascript if typeof variable == function

Kontrola v javascript zda funkce existuje

Check if a Javascript Function Exists or Is Defined.



      function myFunctionName() {
          alert('I am myFunctionName');
      }

      

          if (typeof myFunctionName == 'function') {
              myFunctionName();
          }

77LW NO topic_id

Další témata ....(Topics)

html tags examples | html-tags-examples

HTML TAGS EXAPLES

ANCHOR:


<a href="#bla">bla target</a>
invisible target 
<a name="bla">bla</a> 
 OR visible target
<h2 id="bla"></h2>
JavaScript
var elmnt = document.getElementById("bla");
elmnt.scrollIntoView();

Invisible hidden collabsible toggle switch DIV


<div id="idDiv">Hello</div>
// javascript button onclick
if(show){
 idDiv.style.display === "block";
}else{
 idDiv.style.display = "none";
}

Date: 16.07.2020 - 10:27

htaccess code | htaccess-code

HTTP to HTTPS


# only one RewriteEngine On can be used in htaccess!!!!!!!!!!!!!! 
RewriteEngine On

# all redirection HTTP -> HTTPS
# HTTPS off / if start with http.....
# off equality !=on 
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

example.com to www.example.com


# redirection no www -> https://www.
RewriteCond %{HTTP_HOST} !^www. [NC]
RewriteRule ^(.*)$ https://www.%{HTTP_HOST}/$1 [R=301,L]

Change sitemap.txt to sitemap.php if url //domain.com/sitemap.txt


# //domain.com/sitemap.txt open sitemap.php
# in sitemap.php is function what return list of address
RewriteRule ^sitemap\.txt$ sitemap.php [L]
RewriteRule ^sitemap$ sitemap.php [L]

Remove www. before subdomain name

www.subdomain.example.com
to
subdomain.example.com


RewriteCond %{HTTP_HOST} (^|\.)(www\.)([^\.]*)\.example\.com$ [NC]
RewriteRule (.*) https://%3.example.com/$1  [R=301,QSA,L]

Remove dust before subdomain.example.com


# www.bla.www.m.bla.subdomain.example.com to subdomain.example.com
RewriteCond %{HTTP_HOST} (.*)(subdomain.example.com$) [NC]
RewriteRule (.*) https://subdomain.example.com/$1  [R=301,QSA,L]

Remove only one www. before domain name


# redirection www. -> https://
RewriteCond %{HTTP_HOST} ^www.(.*)$ [NC]
RewriteRule ^(.*)$ https://%1/$1 [R=301,L]

Re: Regulérní výrazy regex nápady a šablony | re-regulerni-vyrazy-regex-napady-a-sablony-id-2313

Odkazy na online regex editory:

https://regex101.com/

https://www.debuggex.com/r/LyIpMYTAhJ9Gja4x

Timer javascript | timer-javascript

Timer in javascript example source code will opening random link in random time.


// setTimeout() 
// clearTimeout()

var start = new Date();

function timedCount()
{
 var now = new Date();
 var resultMilliSeconds = now.getTime() - start.getTime();
 // create some div with id txt
 document.getElementById('txt').innerHTML = resultMilliSeconds;
}
var t = setTimeout("timedCount()",1000);
// clearTimeout(t); // for stopping create button with onclick clearTimeout(t)

Použití timeru v javasciptu. Příklad otvírá náhodně náhodný odkaz v okně prohlížeče za náhodný časový interval.


var c=0;
var t = new String().toString();
var t2 = new String().toString();
var timer_is_on=0;
var newWindow;
function open2(url, opt){
  if (opt == 0) // current window
    window.location = url;
  else if (opt == 1){ // new window
   if(newWindow) newWindow.open(url,"_parent");
   else
   newWindow = window.open(url);
   
   }
  else if (opt == 2) // background window
    {window.open(url); self.focus();}
}
var ar = new Array (
"https://www.okhelp.cz/polevky/"
,"https://www.okhelp.cz/auto-moto/"
,"https://www.okhelp.cz/pc-mobily/"
);

function timedCount()
{
var randomnumber=Math.floor(Math.random()*ar.length)
open2(ar[randomnumber],1);

document.getElementById('txt').value=c;
c=c+1;
t=setTimeout("timedCount()",1000 * (randomnumber + 4));

}

function doTimer()
{
if (!timer_is_on)
  {
  timer_is_on=1;
  timedCount();
  
  }
}

function stopCount()
{
clearTimeout(t);
clearTimeout(t2);

timer_is_on=0;
}    
    </script>
    
    
</head>
<body>

<form>
<input type="button" value="Start count!" onClick="doTimer()">
<input type="text" id="txt">
<input type="button" value="Stop count!" onClick="stopCount()">
</form>

javascript check if page correctly loaded | javascript-check-if-page-correctly-loaded


Příklad vychází z předpokladu, že těsně před konečným  
tagem /BODY je kontejner tag s názvem < footer>< /footer>.
Mezeru < TAGNAME nutno odstranit v reálném kódu.
Pokud tento tag je nalezen, lze předpokládat, že uživatel
stránku již uvidí celou, protože většina prohlížečů si s
tím poradí a doplní chybějící uzavírací tagy BODY a HTML.


// < TAGNAME remove space after < !!!!!
< BODY onload="myFunction">
< sript>
function myFunction() {
var x = document.getElementsByTagName ("footer");
  if(x.length === 0)
    alert("Page not loaded correctly ... not find tag footer x" + x);
  else 
    alert("Heureka! :) FOOTER is loaded!");
} 
< /script>

Editace: 21.5.2020 - 20:58
Počet článků v kategorii: 77
Url:function-exist-javascript

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