Javascript Articles - Page 527 of 671

The DataTransfer object holds data about the drag and drop operation. This data can be retrieved and set in terms of various attributes associated with the DataTransfer object.The following are the attributes:Sr.No.DataTransfer attributes and their description1dataTransfer.dropEffect [ = value ]Returns the kind of operation that is currently selected.This attribute can be set, to change the selected operation.The possible values are none, copy, link, and move.2dataTransfer.effectAllowed [ = value ]Returns the kinds of operations that are to be allowed.This attribute can be set, to change the allowed operations.The possible values are none, copy, copyLink, copyMove, link, linkMove, move, all and uninitialized.3dataTransfer.typesReturns a DOMStringList ... Read More

To accept a drop, the drop target has to listen to at least three events. The dragenter event, which is used to determine whether the drop target is to accept the drop. If the drop is to be accepted, then this event has to be canceled. The dragover event, which is used to determine what feedback is to be shown to the user. If the event is canceled, then the feedback (typically the cursor) is updated based on the dropEffect attribute's value. Finally, the drop event, which allows the actual drop to be performed.

The event listener methods for all the drag and drop events accept Event object that has a readonly attribute called dataTransfer. The event.dataTransfer returns DataTransfer object associated with the event as follows:function EnterHandler(event) {    DataTransfer dt = event.dataTransfer;    … }You can try to run the following code to implement DataTransfer object:                    #boxA, #boxB { float:left;padding:10px;margin:10px; -moz-user-select:none; }          #boxA { background-color: #6633FF; width:75px; height:75px; }          #boxB { background-color: #FF6699; width:150px; height:150px; }             ... Read More

To make an image scale on mouse over, use Vanilla JavaScript library.On mouse move, set it like the following:function move(e) {    var pos = getMousePos(myCanvas, e);    context.drawImage(img, -pos.x, -pos.y, img.width, img.height); }For canvas://add event listener we need myCanvas.addEventListener('mouseout', display, false); myCanvas.addEventListener('mousemove', move, false);function display() {    context.drawImage(img, 0, 0, img.width>>1, img.height>>1); }

Maybe, you are using += with innerHTML. Try the following:var myNum = [1,2,3]; var myStr; myStr = ""; for( var a in myNum) myStr += "" + a + ""; myStr += ""; id("numberList").innerHTML = myStr;

To pass values, let us say our is the following, with page new.html,StructureThe JS will be:$( document ).on( "pageinit", "#new", function( event ) {    var myParam = $(this).data("url").split("?")[1];    myParam = parameters.replace("structure=","");    alert(myParam); });

No, you will not be able to prevent the prompt. It is a security feature because not every user would want to share its location.As stated by W3C:A conforming implementation of this specification must provide a mechanism that protects the user's privacy and this mechanism should ensure that no location information is made available through this API without the user's express permission.

The HTML5 file Blob.slice() method is useful for creating a Blob object containing the data. This data is in the specified range of bytes of the source Blob. It uses XMLHttpRequest as in the below example.Let us see an example to send and receive binary data using slice(). This example sends a text and uses the POST method to send the "file" to the server:var val = new XMLHttpRequest(); val.open("POST", url, true); val.onload = function (event) { }; var blob = new Blob(['demo'], {type: 'text/plain'}); val.send(blob);For video:req.onload = function () {    var blob_uri = URL.createObjectURL(this.response);    myElement.appendChild(document.createElement("source")).src = ... Read More

For this, you can use the SVG elements. Let us see an example:           DEMO          

Drag and Drop (DnD) is powerful User Interface concept that makes it easy to copy, reorder and deletion of items with the help of mouse clicks. This allows the user to click and hold the mouse button down over an element, drag it to another location, and release the mouse button to drop the element there.For drag and drop:                    #boxA, #boxB {float:left;padding:10px;margin:10px; -moz-user-select:none;}          #boxA { background-color: #6633FF; width:75px; height:75px; }          #boxB { background-color: #FF6699; width:150px; height:150px; }       ... Read More