Linki

• github przydatne składnie
• javascript tutorial (w3schools)
• JavaScript reference (w3schools)

Snippety

1. Ajax (w3schools)
   

   var req = new XMLHttpRequest();
   // the request must be in the same domain as the containing webpage
   req.open("GET", "/cgi-bin/test.cgi", false);
   req.send();
   document.write(req.responseText);

2. download file (workaround for "save to a local file")

   var s = "text";
   var blob = new Blob([s]);
   var o = URL.createObjectURL(blob);
   var e = document.createElement("a");
   e.href = o;
   e.innerHTML = "link";
   e.download = "save_as_filename.txt";
   document.body.appendChild(e);
   // creates a new link at the bottom of the page, that can be saved locally
   

3. enumerate NodeList

   var aElem = document.getElementsByTagName("input");
   Array.prototype.forEach.call(aElem, function(e) {
     console.log(e.name);
   });

4. events

   var inp = document.body.getElementsByTagName("input").item(3);
   inp.onkeydown = null
   inp.onkeypress = null;
   document.onkeypress = function (e) {
     console.log(String.fromCharCode(e.charCode) + '=' + e.charCode);
     // getting int from str, i.g. parseInt("a0", 16)
     // to get char code: str.charCodeAt()
     return false;
   };
   
   elem.addEventListener("click", function(){
     alert("event");
   });
   aa
   

5. logging

   console.log('something');

6. modifying document
   

     span = document.getElementById('dataMod');
     if (span != null) {
       data = dataMod.textContent.substring(8, 18);
       span.textContent = data.substring(8, 10) + '.' + data.substring(5, 7)
                          + '.' + data.substring(0, 4);
     }

7. style, toggleVisibility

   <button onclick='toggleVisibility()'>Rozwiązanie</button>
   <div id="sol">
   <script>
   var bVisible = true;
   function toggleVisibility()
   {
     bVisible = !bVisible;
     sVisible = bVisible ? "initial" : "hidden"; // "visible"
     document.getElementById('sol').style.visibility = sVisible;
   }
   toggleVisibility();
   </script>
   b</div>
   

8. timeout
   

     window.setTimeout(fun, 1000); /* possible args after timeout in ms */
   
     // cancel all timeouts http://stackoverflow.com/a/8860203/772981
     var id = window.setTimeout(function() {}, 0);
     while (id--) {
       window.clearTimeout(id); // will do nothing if no timeout with id is present
     }