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<title>图片跨域上传示例 - Editor.md examples</title>
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<div id="layout" style="height: 2000px;background: #f6f6f6;">
<header>
<h1>图片跨域上传示例</h1>
<p>Image cross-domain upload example.</p>
</header>
<div id="test-editormd">
<textarea style="display:none;">#### Settings
```javascript
{
imageUpload : true,
imageFormats : ["jpg", "jpeg", "gif", "png", "bmp", "webp"],
imageUploadURL : "http://xxxxxxx/editor.md/examples/php/cross-domain-upload.php?test=dfdf",
crossDomainUpload : true,
uploadCallbackURL : "http://xxxxxx/upload_callback.html?test=dfdf"
}
```
#### 跨域上传原理
利用 iframe 来实现，A 站 POST 到 B 站，B 站处理上传后再跳转回到 A 站的 callback 页面，callback 页面此时在 iframe 内（即同域下），再通过 window.parent 就可以操作父页面的任意元素了。
#### 跨域上传示例 PHP 版
当前域名：blog.xxx.com/post.php
```html
<form method="post" target="upload-iframe" enctype="multipart/form-data" action="http://static.xxx.com/uploader.php?callback=http://blog.xxx.com/upload-callback.html">
<input type="file" name="file" accept="image/*" />
<input type="submit" id="submit" value="开始上传" />
</form>
<iframe name="upload-iframe" style="display:none;" frameborder="0"></iframe>
```
图片服务器：static.xxx.com/uploader.php
```php
<?php
header("Access-Control-Allow-Origin: *"); // Setting allow domian name
$file = 'uploads/' . $_FILES['file']['name'];
// 详细过程略
move_uploaded_file($_FILES['file']['tmp_name'], $file);
$location = $_GET['callback'].'?success=1&message=xxxxxxx&url=http://static.xxx.com/2015/02/15'.$file.'&temp='.date('ymdhis');
header('location:' . $location);
exit;
?>
```
当前域名：blog.xxx.com/upload-callback.html
```html
<script type="text/javascript">
var query = {};
var urlParams = window.location.search.split('?')[1];
urlParams = urlParams.split("&");
for (var i = 0; i< urlParams.length; i++) {
var param = urlParams[i].split("=");
query[param[0]] = param[1];
}
var imageDialog = window.parent.document.getElementById(query['dialog_id']);
//console.log(imageDialog, window.parent.document, window.parent, query);
</script>
```</textarea>
</div>
</div>
<script src="js/jquery.min.js"></script>
<script src="../editormd.js"></script>
<script type="text/javascript">
$(function() {
var testEditor = editormd("test-editormd", {
width : "90%",
height : 640,
markdown : "",
path : '../lib/',
imageUpload : true,
imageFormats : ["jpg", "jpeg", "gif", "png", "bmp", "webp"],
imageUploadURL : "http://www.ipandao.com/editor.md/examples/php/cross-domain-upload.php?test=dfdf",
crossDomainUpload : true,
uploadCallbackURL : "http://localhost/editor.md/examples/php/upload_callback.html?test=dfdf"
/*
跨域时，上传的图片服务器后台只需要返回一个跳转 URL 并跳转到原页面同域下的 callback 页面，结构如下：
{
success : 0 | 1, // 0 表示上传失败，1 表示上传成功
message : "提示的信息，上传成功或上传失败及错误信息等。",
dialog_id : $_GET['dialog_id'],
url : "远程图片地址" // 上传成功时才返回
}
*/
});
});
</script>
</body>
</html>