我目前有一个 webapp，其视图是使用 ExtJS 6 编写的：我们目前使用 Java 小程序，其目的是允许用户将文件从文件系统拖放到 Web 服务器。 我的目标是删除该小程序，并使用 ExtJS6 处理拖放：这可能吗？
我试图在文档中搜索它，但我发现的唯一主题 (https://docs.sencha.com/extjs/6.0/core_concepts/drag_drop.html) 是关于拖放框架元素的。
【问题讨论】：
标签： java extjs drag-and-drop applet extjs6
fiddle 中包含的窗口允许用户将文件从文件系统拖放到 Web 服务器。
源代码：
Ext.application({
name: 'Fiddle',
launch: function() {
var store = Ext.create('Ext.data.Store', {
fields: ['name', 'size', 'file', 'status']
});
var postDocument = this.postDocument;
Ext.widget('container', {
renderTo: Ext.getBody(),
items: [{
multiSelect: true,
xtype: 'grid',
id: 'UploadGrid',
columns: [{
header: 'Name',
dataIndex: 'name',
flex: 2
}, {
header: 'Size',
dataIndex: 'size',
flex: 1,
renderer: Ext.util.Format.fileSize
}, {
header: 'Status',
dataIndex: 'status',
flex: 1,
renderer: this.rendererStatus
}],
viewConfig: {
emptyText: 'Drop Files Here',
deferEmptyText: false
},
store: store,
listeners: {
drop: {
element: 'el',
fn: 'drop'
},
dragstart: {
element: 'el',
fn: 'addDropZone'
},
dragenter: {
element: 'el',
fn: 'addDropZone'
},
dragover: {
element: 'el',
fn: 'addDropZone'
},
dragleave: {
element: 'el',
fn: 'removeDropZone'
},
dragexit: {
element: 'el',
fn: 'removeDropZone'
},
},
noop: function(e) {
e.stopEvent();
},
addDropZone: function(e) {
if (!e.browserEvent.dataTransfer || Ext.Array.from(e.browserEvent.dataTransfer.types).indexOf('Files') === -1) {
return;
}
e.stopEvent();
this.addCls('drag-over');
},
removeDropZone: function(e) {
var el = e.getTarget(),
thisEl = this.getEl();
e.stopEvent();
if (el === thisEl.dom) {
this.removeCls('drag-over');
return;
}
while (el !== thisEl.dom && el && el.parentNode) {
el = el.parentNode;
}
if (el !== thisEl.dom) {
this.removeCls('drag-over');
}
},
drop: function(e) {
e.stopEvent();
Ext.Array.forEach(Ext.Array.from(e.browserEvent.dataTransfer.files), function(file) {
store.add({
file: file,
name: file.name,
size: file.size,
status: 'Ready'
});
});
this.removeCls('drag-over');
},
tbar: [{
text: "Upload",
handler: function() {
for (var i = 0; i < store.data.items.length; i++) {
if (!(store.getData().getAt(i).data.status === "Uploaded")) {
store.getData().getAt(i).data.status = "Uploading";
store.getData().getAt(i).commit();
//replace "insert your upload url here" with the real url
postDocument("insert your upload url here", store, i);
}
}
}
}, {
text: "Erase EVERYTHING",
handler: function() {
store.reload();
}
}, {
text: "Erase uploaded files",
handler: function() {
for (var i = 0; i < store.data.items.length; i++) {
var record = store.getData().getAt(i);
if ((record.data.status === "Uploaded")) {
store.remove(record);
i--;
}
}
}
}, {
text: "Erase selected files",
handler: function() {
store.remove(Ext.getCmp('UploadGrid').getSelection());
}
}]
}],
padding: 20
});
},
rendererStatus: function(value, metaData, record, rowIndex, colIndex, store) {
var color = "grey";
if (value === "Ready") {
color = "blue";
} else if (value === "Uploading") {
color = "orange";
} else if (value === "Uploaded") {
color = "green";
} else if (value === "Error") {
color = "red";
}
metaData.tdStyle = 'color:' + color + ";";
return value;
},
postDocument: function(url, store, i) {
var xhr = new XMLHttpRequest();
var fd = new FormData();
fd.append("serverTimeDiff", 0);
xhr.open("POST", url, true);
fd.append('index', i);
fd.append('file', store.getData().getAt(i).data.file);
//xhr.setRequestHeader("Content-Type","multipart/form-data");
xhr.setRequestHeader("serverTimeDiff", 0);
xhr.onreadystatechange = function() {
if (xhr.readyState == 4 && xhr.status == 200) {
//handle the answer, in order to detect any server side error
if (Ext.decode(xhr.responseText).success) {
store.getData().getAt(i).data.status = "Uploaded";
} else {
store.getData().getAt(i).data.status = "Error";
}
store.getData().getAt(i).commit();
} else if (xhr.readyState == 4 && xhr.status == 404) {
store.getData().getAt(i).data.status = "Error";
store.getData().getAt(i).commit();
}
};
// Initiate a multipart/form-data upload
xhr.send(fd);
}
});
【讨论】：
为了支持文件的拖放，您可以使用以下events：drop、dragstart、dragenter、dragover、dragleave、dragexit。
一个工作示例：https://fiddle.sencha.com/#fiddle/10v9
Ext.application({
name: 'Fiddle',
launch: function() {
var store = Ext.create('Ext.data.Store', {
fields: ['name', 'size', 'file']
});
Ext.widget('container', {
renderTo: Ext.getBody(),
items: [{
xtype: 'grid',
columns: [{
header: 'Name',
dataIndex: 'name',
flex: 2
}, {
header: 'Size',
dataIndex: 'size',
flex: 1,
renderer: Ext.util.Format.fileSize
}],
viewConfig: {
emptyText: 'Drop Files Here',
deferEmptyText: false
},
store: store,
listeners: {
drop: {
element: 'el',
fn: 'drop'
},
dragstart: {
element: 'el',
fn: 'addDropZone'
},
dragenter: {
element: 'el',
fn: 'addDropZone'
},
dragover: {
element: 'el',
fn: 'addDropZone'
},
dragleave: {
element: 'el',
fn: 'removeDropZone'
},
dragexit: {
element: 'el',
fn: 'removeDropZone'
},
},
noop: function(e) {
e.stopEvent();
},
addDropZone: function(e) {
if (!e.browserEvent.dataTransfer || Ext.Array.from(e.browserEvent.dataTransfer.types).indexOf('Files') === -1) {
return;
}
e.stopEvent();
this.addCls('drag-over');
},
removeDropZone: function(e) {
var el = e.getTarget(),
thisEl = this.getEl();
e.stopEvent();
if (el === thisEl.dom) {
this.removeCls('drag-over');
return;
}
while (el !== thisEl.dom && el && el.parentNode) {
el = el.parentNode;
}
if (el !== thisEl.dom) {
this.removeCls('drag-over');
}
},
drop: function(e) {
e.stopEvent();
Ext.Array.forEach(Ext.Array.from(e.browserEvent.dataTransfer.files), function(file) {
store.add({
file: file,
name: file.name,
size: file.size
});
console.log(file);
});
this.removeCls('drag-over');
}
}],
padding: 20
});
}
});
【讨论】：
FileReader，你可以使用FormData。
我正在使用我在 sencha 论坛中找到的解决方案：
Ext.define('FileDropper', {
extend: 'Ext.plugin.Abstract',
alias: 'plugin.filedropper',
overCls: '',
init: function(c) {
this.target = c;
c.on({
element: 'el',
scope: this,
dragover: this.onDragOver,
dragenter: this.onDragEnter,
dragLeave: this.onDragLeave,
drop: this.onDrop
});
},
onDragOver: function(e) {
e.stopEvent();
},
onDragEnter: function(e) {
this.target.addCls(this.overCls);
e.stopEvent();
},
onDragLeave: function() {
this.target.removeCls(this.overCls);
},
onDrop: function(e) {
var callback = this.callback,
scope = this.scope || this;
e.stopEvent();
this.target.removeCls(this.overCls);
if (callback) {
callback.call(scope, e.browserEvent.dataTransfer.files);
}
}
});
像这样将插件添加到您的视图中：
Ext.define('MyPanel', {
extend: 'Ext.Panel',
// ... your content
plugins: [{
ptype: 'filedroppper'
overCls: 'foo'
callback: function(files) {
// handle your upload
}
}]
});
您只需在回调中处理删除的文件：
callback: function (files) {
var url = 'example.org'
var xhr = new XMLHttpRequest();
var fd = new FormData();
xhr.open("POST", url, true);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
// Handle response.
alert(xhr.responseText); // handle response.
}
};
for (var i = 0; i < files.length; i++) {
fd.append('files', files.item(i));
}
// Initiate a multipart/form-data upload
xhr.send(fd);
}
但如果您使用FormData()，请确保您不必支持旧浏览器。
【讨论】：