Dropupload"

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*JavaScript API: <javadoc directory="jsdoc">zkmax.wgt.Dropupload</javadoc>
 
*JavaScript API: <javadoc directory="jsdoc">zkmax.wgt.Dropupload</javadoc>
 
*Style Guide: N/A
 
*Style Guide: N/A
*[http://www.zkoss.org/product/edition.dsp Available in ZK EE only]
+
{{ZK EE}}
  
 
= Employment/Purpose =
 
= Employment/Purpose =
<tt>Dropupload</tt> leverages HTML 5 technology to handle file uploading where users can simply drag and drop the file(s) they want to upload into <tt>Dropupload</tt> and the uploading process will start automatically. The behaviour and operation of this <tt>Dropupload</tt> component is similar to ZK's [http://books.zkoss.org/wiki/ZK_Component_Reference/Essential_Components/Button#File_Upload '''file upload button'''] but with better user experience and performance.
+
<code>Dropupload</code> leverages HTML 5 technology to handle file uploading where users can simply drag and drop the file(s) they want to upload into <code>Dropupload</code> and the uploading process will start automatically. The behaviour and operation of this <code>Dropupload</code> component is similar to ZK's [http://books.zkoss.org/wiki/ZK_Component_Reference/Essential_Components/Button#File_Upload '''file upload button'''] but with better user experience and performance.
  
 
= Example =
 
= Example =
 
+
Following is a typical example of its implementation, it will always show component and limit the upload file size.
Following is a typical example of its implementation
 
 
 
 
<source lang="xml">
 
<source lang="xml">
 
<dropupload maxsize="5120" detection="none" onUpload="doSomething(event)">
 
<dropupload maxsize="5120" detection="none" onUpload="doSomething(event)">
Line 23: Line 21:
 
</dropupload>
 
</dropupload>
 
</source>
 
</source>
 +
 +
Another example, it will detect the drag action:
 +
<source lang="xml">
 +
<zk>
 +
    <vlayout>
 +
        <image id="img" />
 +
        Upload your hot shot:
 +
        <dropupload maxsize="-1" content="content" detection="browser" onUpload="img.setContent(event.media)" />
 +
    </vlayout>
 +
</zk>
 +
</source>
 +
 +
'''Drop area'''
 +
[[File:initial-run.png]]
 +
 +
'''File dragged over area'''
 +
[[File:dragged-over.png]]
 +
 +
'''Image uploaded and displayed'''
 +
[[File:uploaded-image.png]]
  
 
= Maxsize =
 
= Maxsize =
  
The <tt>maxsize</tt> attribute is used for limiting the file size of a single file in which users are allowed to upload. Users are allowed to drag in two or more files at once but each of them has to be smaller than the size set by <tt>Maxsize</tt>. If one of the files is larger than the size set by <tt>Maxsize</tt>, an error message will occur and nothing will be uploaded.  
+
The <code>maxsize</code> attribute is used for limiting the file size of a single file in which users are allowed to upload. Users are allowed to drag in two or more files at once but each of them has to be smaller than the size set by <code>Maxsize</code>. If one of the files is larger than the size set by <code>Maxsize</code>, an error message will occur and nothing will be uploaded.  
  
 
For example, in the case of the previous sample code, you can upload multiple files, say, four files that are smaller than 5120KB at once but if one of them exceeds 5120KB, then an exception will occur and none of the four files will be uploaded to the server.  
 
For example, in the case of the previous sample code, you can upload multiple files, say, four files that are smaller than 5120KB at once but if one of them exceeds 5120KB, then an exception will occur and none of the four files will be uploaded to the server.  
  
The unit of <tt>MaxsizeM</tt> attribute is in KB. If it is not assigned a value, it will use the value of '''Configuration.getMaxUploadSize()''' automatically while a negative value would mean that the file size is set as unlimited.
+
The unit of <code>MaxsizeM</code> attribute is in KB. If it is not assigned a value, it will use the value of '''Configuration.getMaxUploadSize()''' automatically while a negative value would mean that the file size is set as unlimited.
  
 
= Detection =
 
= Detection =
  
This attribute will define what users see when they drag and drop files into the application i.e. how the <tt>Dropupload</tt> component and its content will appear according to their action.
+
This attribute will define what users see when they drag and drop files into the application i.e. how the <code>Dropupload</code> component and its content will appear according to their action.
  
 
There are four valid values of <code>detection</code> :
 
There are four valid values of <code>detection</code> :
* <code>none</code> : Ignore users' drag action, always show <tt>Dropupload</tt> and its content.
+
* <code>none</code> : Ignore users' drag action, always show <code>Dropupload</code> and its content.
* <code>browser</code> (default setting) : <tt>Dropupload</tt> is not visible in the application initially but shows up along with the content when users drag files into the browser.  
+
* <code>browser</code> (default setting) : <code>Dropupload</code> is not visible in the application initially but shows up along with the content when users drag files into the browser.  
* <code>self</code> : <tt>Dropupload</tt> is visible in the application initially but the content only appears when users drag files into the component.  
+
* <code>self</code> : <code>Dropupload</code> is visible in the application initially but the content only appears when users drag files into the component.  
 
* id of another component : Behaviour of this value is almost identical to <code>self</code>, except that the trigger area is inside the component of the appointed id.  
 
* id of another component : Behaviour of this value is almost identical to <code>self</code>, except that the trigger area is inside the component of the appointed id.  
  
 
The <code>content</code> value can be any HTML string and remember to surround the content value by <code>CDATA</code> block .
 
The <code>content</code> value can be any HTML string and remember to surround the content value by <code>CDATA</code> block .
  
'''Note''' : A <tt>Dropupload</tt> with <code>detection="browser"</code> cannot be used with another <tt>Dropupload</tt> component that has a different <tt>detection</tt> setting; users won't be able to drag a file into the component successfully.
+
'''Note''' : A <code>Dropupload</code> with <code>detection="browser"</code> cannot be used with another <code>Dropupload</code> component that has a different <code>detection</code> value; users won't be able to drag a file into the component successfully.
 +
 
 +
= Anchor =
 +
{{versionSince| 7.0.2}}
 +
This attribute allows the dropupload component to anchor to another component and overlay that component when the user drag & drops files to the browser. Much like how Gmail works when dropping attachments to emails.
 +
 
 +
== Example ==
 +
[[File:Dropupload_Anchor.png]]
 +
[[File:Dropupload_Anchor_1.png]]
 +
 
 +
<source lang="xml" highlight="13">
 +
<zk>
 +
<div height="100px"></div>
 +
<tabbox height="100px">
 +
<tabs>
 +
<tab id="A" label="Tab A" />
 +
<tab id="B" label="Tab B" />
 +
</tabs>
 +
<tabpanels id="tps">
 +
<tabpanel>This is panel A</tabpanel>
 +
<tabpanel>This is panel B</tabpanel>
 +
</tabpanels>
 +
</tabbox>
 +
<dropupload anchor="${tps}"></dropupload>
 +
</zk>
 +
</source>
 +
 
 +
= Accept =
 +
{{versionSince| 10.0.0}}
 +
This attribute specifies [https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types the MIME types] that the server accepts. Similar to [[#Maxsize|the maxsize attribute]], if one of the files does not match the acceptable file types, nothing will be uploaded. For example, the following example only accepts audio and .png files:
 +
<source lang="xml">
 +
<dropupload accept="audio/*, .png"/>
 +
</source>
 +
 
 +
= MaxFileCount =
 +
 
 +
Default: <code>-1</code>
 +
 
 +
Set the maximum number of files a user can upload at once, -1 means no limit. When the number of upload files exceeds the max file count, nothing will be uploaded and <code>onMaxFileCountExceed</code> event will be fired, developers can listen to that event and get the number of uploaded files by calling <code>event.getData()</code>.
 +
 
 +
 
 +
 
 +
For example (MVVM pattern):
 +
 
 +
<source lang="xml">
 +
  <dropupload onMaxFileCountExceed="@command('maxFileCountExceed', filesCount=event.data)" />
 +
</source>
 +
 
 +
<source lang="java">
 +
  @Command
 +
  public void maxFileCountExceed(@BindingParam("filesCount") Integer filesCount) {
 +
    Messagebox.show(filesCount + " files exceed the number of upload files limitation.");
 +
  }
 +
</source>
 +
 
 +
= Do not Convert File =
 +
By default, ZK will convert upload file to image, audio and text file if possible. Developer can use <code>native="true"</code> to demand ZK don't convert file.
  
 
= Customized File Viewer =
 
= Customized File Viewer =
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#'''destroy()''': After the file has been uploaded or if the uploading has been canceled or if the uploading has caused an error, this function will be invoked.
 
#'''destroy()''': After the file has been uploaded or if the uploading has been canceled or if the uploading has caused an error, this function will be invoked.
  
After customizing your JavaScript class which in this case is <code>foo.MyFileViewer</code>, assign it to <tt>Dropupload</tt> using the <code>viewerClass</code> attribute as demonstrated below:  
+
After customizing your JavaScript class which in this case is <code>foo.MyFileViewer</code>, assign it to <code>Dropupload</code> using the <code>viewerClass</code> attribute as demonstrated below:  
  
 
<source lang="xml"><dropupload viewClass="foo.MyFileViewer" content="custom viewer" detection="none" /></source>
 
<source lang="xml"><dropupload viewClass="foo.MyFileViewer" content="custom viewer" detection="none" /></source>
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=== Uploader ===
 
=== Uploader ===
 
Below is a summarised description table of the ''Uploader'' when passed a selected file from the user.  
 
Below is a summarised description table of the ''Uploader'' when passed a selected file from the user.  
{| border="1"
+
{| class='wikitable' | width="100%"
 
|-
 
|-
 
!Method  || Usage
 
!Method  || Usage
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== Transforming the original File Viewer ==
 
== Transforming the original File Viewer ==
  
Customized File Viewers written in the past can also be applied to <tt>Dropupload</tt> with only some slight changes :  
+
Customized File Viewers written in the past can also be applied to <code>Dropupload</code> with only some slight changes :  
* Originally,  the second parameter of <code>$init()</code> is <code>filenm</code> (type: String). To apply it to the new <tt>Dropupload</tt> component, change the second parameter to <code>file</code> (type: File) object and add another line of <code>filenm = file.name</code> to solve the issue.
+
* Originally,  the second parameter of <code>$init()</code> is <code>filenm</code> (type: String). To apply it to the new <code>Dropupload</code> component, change the second parameter to <code>file</code> (type: File) object and add another line of <code>filenm = file.name</code> to solve the issue.
  
 
<source lang="javascript">  
 
<source lang="javascript">  
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* The first parameter of <code>update()</code>, <code>send</code> would originally pass an integer value ranging from 0 to 100, representing the percentage of the uploading process whereas now it will pass the value of the already uploaded size of data in Bytes.
 
* The first parameter of <code>update()</code>, <code>send</code> would originally pass an integer value ranging from 0 to 100, representing the percentage of the uploading process whereas now it will pass the value of the already uploaded size of data in Bytes.
  
= After Uploading as been Completed =
+
= Customize Upload Size Exceeding Message =
 +
Please refer to [[ZK_Component_Reference/Essential_Components/Button#Customize_Upload_Size_Exceeding_Message]]
 +
 
 +
= Event For Completed Uploads =
  
After the uploading has been done, the uploaded files can be retrieved from the companion event, which is an instance of <javadoc>org.zkoss.zk.ui.event.UploadEvent</javadoc>. For example,
+
After the upload is finished, the uploaded files can be retrieved from the companion event, which is an instance of <javadoc>org.zkoss.zk.ui.event.UploadEvent</javadoc>. For example,
  
 
<source lang="xml">
 
<source lang="xml">
Line 156: Line 233:
  
 
= Browser Support =
 
= Browser Support =
As Dropupload uses HTML5 technology, there are several browsers that does not support it. Currently it operates normally on Firefox (v.13), Chrome (v.19) and Safari (v.5.1.x), but IE9, Opera v.11.x cannot use this function.
+
 
 +
As <code>Dropupload</code> leverages HTML5 technology, some browsers don't support it. Currently, it works normally on Firefox (v.13), Chrome (v.19) and Safari (v.5.1.x), but doesn't function in IE 9, Opera v.11.x, and Microsoft Edge.
  
 
Moreover, the <code>detection</code> setting cannot be displayed on some older machines.
 
Moreover, the <code>detection</code> setting cannot be displayed on some older machines.
  
 
= Supported Events =
 
= Supported Events =
{| border="1" | width="100%"
+
{| class='wikitable' | width="100%"
 
! <center>Name</center>
 
! <center>Name</center>
 
! <center>Event Type</center>
 
! <center>Event Type</center>
 
|-
 
|-
| <center><tt>onUpload</tt></center>
+
| <center><code>onUpload</code></center>
 
| '''Event:''' <javadoc>org.zkoss.zk.ui.event.UploadEvent</javadoc>
 
| '''Event:''' <javadoc>org.zkoss.zk.ui.event.UploadEvent</javadoc>
Denotes user has uploaded a file to the component
+
This event will be triggered once a user has uploaded a file.
 +
|-
 +
| <center><code>onMaxFileCountExceed</code></center>
 +
| '''Event:''' <javadoc>org.zkoss.zk.ui.event.Event</javadoc>
 +
This event will be triggered when number of upload files exceed the maxFileCount.
 
|}
 
|}
 
*Inherited Supported Events: [[ZK_Component_Reference/Base_Components/LabelImageElement#Supported_Events | LabelImageElement]]
 
*Inherited Supported Events: [[ZK_Component_Reference/Base_Components/LabelImageElement#Supported_Events | LabelImageElement]]
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= Use Cases =
 
= Use Cases =
{| border='1px' | width="100%"
+
{| class='wikitable' | width="100%"
 
! Version !! Description !! Example Location
 
! Version !! Description !! Example Location
 
|-
 
|-
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{{LastUpdated}}
 
{{LastUpdated}}
  
{| border='1px' | width="100%"
+
{| class='wikitable' | width="100%"
 
! Version !! Date !! Content
 
! Version !! Date !! Content
 
|-
 
|-
| 6.1.0
+
| 6.5.0
 
| June, 2012
 
| June, 2012
 
| <javadoc>org.zkoss.zkmax.zul.Dropupload</javadoc> was introduced.
 
| <javadoc>org.zkoss.zkmax.zul.Dropupload</javadoc> was introduced.
 +
|-
 +
| 7.0.2
 +
| March, 2014
 +
| [http://tracker.zkoss.org/browse/ZK-2207 ZK-2207]: Dropupload supports anchor
 +
|-
 +
| 10.0.0
 +
| September, 2023
 +
| [http://tracker.zkoss.org/browse/ZK-4969 ZK-4969]: Dropupload supports accept
 
|}
 
|}
  
 
{{ZKComponentReferencePageFooter}}
 
{{ZKComponentReferencePageFooter}}

Latest revision as of 08:28, 23 February 2024

Dropupload

  • Available for ZK:
  • http://www.zkoss.org/product/zkhttp://www.zkoss.org/whyzk/zkeeVersion ee.png

Employment/Purpose

Dropupload leverages HTML 5 technology to handle file uploading where users can simply drag and drop the file(s) they want to upload into Dropupload and the uploading process will start automatically. The behaviour and operation of this Dropupload component is similar to ZK's file upload button but with better user experience and performance.

Example

Following is a typical example of its implementation, it will always show component and limit the upload file size.

	<dropupload maxsize="5120" detection="none" onUpload="doSomething(event)">
		<attribute name="content"><![CDATA[
			<b>Drop Here</b><br/>
			size < 5MB
		]]></attribute>
	</dropupload>

Another example, it will detect the drag action:

<zk>
    <vlayout>
        <image id="img" />
        Upload your hot shot:
        <dropupload maxsize="-1" content="content" detection="browser" onUpload="img.setContent(event.media)" />
    </vlayout>
</zk>

Drop area Initial-run.png

File dragged over area Dragged-over.png

Image uploaded and displayed Uploaded-image.png

Maxsize

The maxsize attribute is used for limiting the file size of a single file in which users are allowed to upload. Users are allowed to drag in two or more files at once but each of them has to be smaller than the size set by Maxsize. If one of the files is larger than the size set by Maxsize, an error message will occur and nothing will be uploaded.

For example, in the case of the previous sample code, you can upload multiple files, say, four files that are smaller than 5120KB at once but if one of them exceeds 5120KB, then an exception will occur and none of the four files will be uploaded to the server.

The unit of MaxsizeM attribute is in KB. If it is not assigned a value, it will use the value of Configuration.getMaxUploadSize() automatically while a negative value would mean that the file size is set as unlimited.

Detection

This attribute will define what users see when they drag and drop files into the application i.e. how the Dropupload component and its content will appear according to their action.

There are four valid values of detection :

  • none : Ignore users' drag action, always show Dropupload and its content.
  • browser (default setting) : Dropupload is not visible in the application initially but shows up along with the content when users drag files into the browser.
  • self : Dropupload is visible in the application initially but the content only appears when users drag files into the component.
  • id of another component : Behaviour of this value is almost identical to self, except that the trigger area is inside the component of the appointed id.

The content value can be any HTML string and remember to surround the content value by CDATA block .

Note : A Dropupload with detection="browser" cannot be used with another Dropupload component that has a different detection value; users won't be able to drag a file into the component successfully.

Anchor

Since 7.0.2 This attribute allows the dropupload component to anchor to another component and overlay that component when the user drag & drops files to the browser. Much like how Gmail works when dropping attachments to emails.

Example

Dropupload Anchor.png Dropupload Anchor 1.png

<zk>
	<div height="100px"></div>
	<tabbox height="100px">
		<tabs>
			<tab id="A" label="Tab A" />
			<tab id="B" label="Tab B" />
		</tabs>
		<tabpanels id="tps">
			<tabpanel>This is panel A</tabpanel>
			<tabpanel>This is panel B</tabpanel>
		</tabpanels>
	</tabbox>
	<dropupload anchor="${tps}"></dropupload>
</zk>

Accept

Since 10.0.0 This attribute specifies the MIME types that the server accepts. Similar to the maxsize attribute, if one of the files does not match the acceptable file types, nothing will be uploaded. For example, the following example only accepts audio and .png files:

	<dropupload accept="audio/*, .png"/>

MaxFileCount

Default: -1

Set the maximum number of files a user can upload at once, -1 means no limit. When the number of upload files exceeds the max file count, nothing will be uploaded and onMaxFileCountExceed event will be fired, developers can listen to that event and get the number of uploaded files by calling event.getData().


For example (MVVM pattern):

  <dropupload onMaxFileCountExceed="@command('maxFileCountExceed', filesCount=event.data)" />
  @Command
  public void maxFileCountExceed(@BindingParam("filesCount") Integer filesCount) {
    Messagebox.show(filesCount + " files exceed the number of upload files limitation.");
  }

Do not Convert File

By default, ZK will convert upload file to image, audio and text file if possible. Developer can use native="true" to demand ZK don't convert file.

Customized File Viewer

Similar to file upload button, the default file viewer will show the uploading progress via a pop-up bar as illustrated below.

DefaultFileUploadVeiwer.JPG

Alternatively, developers can also design customized File Viewer by implementing a JavaScript class to handle the display screen when uploading files. Below is an example of a customized file viewer where the progress bar is shown at the bottom of the browser.

CustomizedFileUploadVeiwer.JPG


foo.MyFileViewer = zk.$extends(zk.Object, {
	updated: null,
	$init: function (uplder,  file) {
		this._uplder = uplder;
		var id = uplder.id,
			uri = zk.ajaxURI('/web/zk/img/progress2.gif', {au:true}),
			html = '<div id="' + id + '" class="viewer"><image class="float-left" src="' + uri + '"/>'
			+ '<div class="float-left">FileName: ' + file.name
			+ ' <a id="' + id + '-cancel">Cancel</a></div><div class="float-right">'
			+ msgzk.FILE_SIZE + ': <span id="' + id + '-sent">0</span> of '
			+ '<span id="' + id + '-total">0</span></div><div class="clear"></div></div>';
				
		jq(uplder.getWidget().getPage()).append(html);
			
		this.viewer = jq('#'+ id)[0];
		jq('#' + id + '-cancel').click(function() {
			uplder.cancel();
		});
	},
	update: function (sent, total) {
		jq('#'+ this._uplder.id + '-sent').html(Math.round(sent/1000) + msgzk.KBYTES);
		if (!this.updated) {
			this.updated = true;
			jq('#'+ this._uplder.id + '-total').html(Math.round(total/1024)+msgzk.KBYTES);
		}
	},
	destroy: function () {
		jq(this.viewer).remove();
	}
});

In the code snippet above, you can see that there are three functions - $init, update, and destroy.

  1. $init(uplder, file): When the user selects a file from the file chooser, this function will be invoked.
  2. update(send, total): After the uploading engine receives the size that has already been uploaded, this function will be invoked.
    • sent: An integer of the uploaded size.
    • total: An integer of the total uploaded size.
  3. destroy(): After the file has been uploaded or if the uploading has been canceled or if the uploading has caused an error, this function will be invoked.

After customizing your JavaScript class which in this case is foo.MyFileViewer, assign it to Dropupload using the viewerClass attribute as demonstrated below:

<dropupload viewClass="foo.MyFileViewer" content="custom viewer" detection="none" />

Uploader

Below is a summarised description table of the Uploader when passed a selected file from the user.

Method Usage
getWidget Indicate which component the widget belongs to
cancel Stops the uploading process.

Transforming the original File Viewer

Customized File Viewers written in the past can also be applied to Dropupload with only some slight changes :

  • Originally, the second parameter of $init() is filenm (type: String). To apply it to the new Dropupload component, change the second parameter to file (type: File) object and add another line of filenm = file.name to solve the issue.
 
//before 
$init: function (uplder,  filenm) {
	//routine
}

//after
$init: function (uplder, file) {
	var filenm = file.name;
	//routine
}


  • The first parameter of update(), send would originally pass an integer value ranging from 0 to 100, representing the percentage of the uploading process whereas now it will pass the value of the already uploaded size of data in Bytes.

Customize Upload Size Exceeding Message

Please refer to ZK_Component_Reference/Essential_Components/Button#Customize_Upload_Size_Exceeding_Message

Event For Completed Uploads

After the upload is finished, the uploaded files can be retrieved from the companion event, which is an instance of UploadEvent. For example,

<zscript><![CDATA[
public void showFileName(org.zkoss.zk.ui.event.UploadEvent event){
	org.zkoss.util.media.Media[] medias = event.getMedias();
	StringBuffer sb = new StringBuffer();
	for (org.zkoss.util.media.Media m : medias) {
		sb.append(m.getName()+"\n");
	}
	Messagebox.show(sb.toString());
}
]]></zscript>
<dropupload detection="none" onUpload="showFileName(event)" />

Browser Support

As Dropupload leverages HTML5 technology, some browsers don't support it. Currently, it works normally on Firefox (v.13), Chrome (v.19) and Safari (v.5.1.x), but doesn't function in IE 9, Opera v.11.x, and Microsoft Edge.

Moreover, the detection setting cannot be displayed on some older machines.

Supported Events

Name
Event Type
onUpload
Event: UploadEvent

This event will be triggered once a user has uploaded a file.

onMaxFileCountExceed
Event: Event

This event will be triggered when number of upload files exceed the maxFileCount.

Supported Children

*NONE

Use Cases

Version Description Example Location
     

Version History

Last Update : 2024/02/23


Version Date Content
6.5.0 June, 2012 Dropupload was introduced.
7.0.2 March, 2014 ZK-2207: Dropupload supports anchor
10.0.0 September, 2023 ZK-4969: Dropupload supports accept



Last Update : 2024/02/23

Copyright © Potix Corporation. This article is licensed under GNU Free Documentation License.