[英]Image Drag Drop and Upload in Node.js
我正在使用node.js,express,mongoose。
我有一個允許用戶使用的表單1.單擊“上傳圖像”並上傳圖像2.將圖像從計算機拖到保管箱中以上傳圖像
我知道dropzone.js,但決定不使用它只是為了學習如何自己做。
基本上,當用戶點擊上傳或將圖像拖放到保管箱中時,它會顯示在預覽中。 這有效。
以下是我的代碼的相關部分:
new.ejs
<input name="image" type="file" id="image" accept="image/*" style="display:none" onchange="handleFiles(this.files)">
<div id="imageBorder" >
<div id="imageContainer">
<div id="dropbox">
<i class="fa fa-picture-o" aria-hidden="true"></i>
<p> Drop image here or click to upload</p>
</div>
<div id="preview" class="hidden">
</div>
<button id="fileSelect" class="btn btn-primary btn-block">Upload Image</button>
<button id="fileRemove" class="btn btn-primary btn-block">Remove Image</button>
</div>
eventform.js
function eventImageSetup() {
var dropbox = document.getElementById("dropbox"),
fileElem = document.getElementById("image"),
fileSelect = document.getElementById("fileSelect"),
fileRemove = document.getElementById("fileRemove");
$(dropbox).height($('#imageBorder').height());
fileSelect.addEventListener("click", function(e) {
if (fileElem) {
fileElem.click();
e.preventDefault(); // to prevent submit
}
}, false);
fileRemove.addEventListener("click", function(e) {
e.preventDefault(); // prevent submit
if(!$('#preview').hasClass('hidden')) { // If there is an image uploaded
$('#preview').empty();
$('#dropbox').removeClass('hidden');
$('#preview').addClass('hidden');
$('#fileSelect').text('Upload Image');
resetFileInputField();
}
removeError($('#imageError'), $('#image'));
});
dropbox.addEventListener("dragenter", dragenter, false);
dropbox.addEventListener("dragover", dragover, false);
dropbox.addEventListener("drop", drop, false);
} // end of eventImageSetup
function dragenter(e) {
e.stopPropagation();
e.preventDefault();
}
function dragover(e) {
e.stopPropagation();
e.preventDefault();
}
function drop(e) {
e.stopPropagation();
e.preventDefault();
var dt = e.dataTransfer;
var files = dt.files;
handleFiles(files);
}
function handleFiles(files) {
var file = files[0];
console.log("This is the file: ", file);
var imageType = /^image\//;
if (!imageType.test(file.type)) {
// a bunch of code to deal with this...
return;
} else if (file.size > MAX_FILE_SIZE) {
// a bunch of code to deal with this..
return;
} else {
var img = document.createElement("img");
img.onload = function() {
adjustImageSize(img);
};
$('#dropbox').addClass('hidden');
$('#preview').removeClass('hidden');
$('#preview').empty();
$('#preview').append(img);
$('#fileSelect').text('Replace Image');
var reader = new FileReader();
reader.readAsDataURL(file);
reader.onload = function(event) {
img.src = event.target.result;
}
}
}
正如您所看到的,問題是在拖放時, 我實際上從未將文件附加到表單元素 。 我嘗試將文件附加到$('#image')。文件,但顯然你無法解決安全問題。 基本上我繼續閱讀我無法以編程方式添加文件。
任何指導將不勝感激...
var reader = new FileReader();
reader.onload = function(event) {
img.src = event.target.result;
}
reader.readAsDataURL(file);
例
var MAX_FILE_SIZE = Infinity; // ignore this function eventImageSetup() { $(dropbox).height($('#imageBorder').height()); fileSelect.addEventListener("click", function() { image.click(); }, false); fileRemove.addEventListener("click", function() { if (!$('#preview').hasClass('hidden')) { // If there is an image uploaded $('#preview').empty(); $('#dropbox').removeClass('hidden'); $('#preview').addClass('hidden'); $('#fileSelect').text('Upload Image'); resetFileInputField(); } removeError($('#imageError'), $('#image')); }, false); dropbox.addEventListener("dragenter", dragenter, false); dropbox.addEventListener("dragover", dragover, false); dropbox.addEventListener("drop", drop, false); } // end of eventImageSetup function dragenter(e) { e.stopPropagation(); e.preventDefault(); } function dragover(e) { e.stopPropagation(); e.preventDefault(); } function drop(e) { e.stopPropagation(); e.preventDefault(); var dt = e.dataTransfer; var files = dt.files; handleFiles(files); } function handleFiles(files) { var file = files[0]; //console.log("This is the file: ", file); var imageType = /^image\\//; if (!imageType.test(file.type)) { // a bunch of code to deal with this... return; } if (file.size > MAX_FILE_SIZE) { // a bunch of code to deal with this.. return; } var img = document.createElement("img"); img.onload = function() { //adjustImageSize(img); }; $('#dropbox').addClass('hidden'); $('#preview').removeClass('hidden'); $('#preview').empty(); $('#preview').append(img); $('#fileSelect').text('Replace Image'); var reader = new FileReader(); reader.onload = function(e) { img.src = e.target.result; } reader.readAsDataURL(file); } eventImageSetup();
#dropbox { border: 2px dashed; height: 100px; width: 230px; }
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <input name="image" type="file" id="image" accept="image/*" style="display:none" onchange="handleFiles(this.files)"> <div id="imageBorder"> <div id="imageContainer"> <div id="dropbox"> <i class="fa fa-picture-o" aria-hidden="true"></i> <p> Drop image here or click to upload</p> </div> <div id="preview" class="hidden"> </div> <button id="fileSelect" type="button" class="btn btn-primary btn-block">Upload Image</button> <button id="fileRemove" type="button" class="btn btn-primary btn-block">Remove Image</button> </div>
側面的言論
fileSelect
而不是document.getElementById('fileSelect')
訪問<input id="fileSelect">
。 type="button"
按鈕元素不會在點擊時提交表單。
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