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05 Nov 2013
Ajax File Upload

ajax file upload


前言

这个是来自一个非常旧的 ajaxfileupload 库。但是非常久不更新了,使用原版的会有很多问题。

http://www.phpletter.com/our-projects/ajaxfileupload/

因此根据需求和 google 到的各种问题,把 google 到的对这个库的各种补丁更新搞在一起,读了下代码,略微整理了下。

另外对于上传文件有这样的库的:http://www.uploadify.com/demos/。对比而言 ajaxfileupload 会更简单轻量很多,只提供基本的 upload 和 ajax 操作,并不会和 uploadify 那样涉及 UI。

使用

html:

<input id='file-upload-btn' type='button' value='提交上传' />
<input id='file-upload-field' type="file" name="content" />

javascript:

/* 为 `提交上传` 按钮绑定异步上传动作 */
$('#file-upload-btn').bind('click', function() {

    /* ajax 请求提交的参数 */
    var post_data = {
        'param1' : 'p1',
        'param2' : 'p2'
    };
    /* post file 的 input id */
    var file_element_id = 'file-upload-field';
    /* post file url */
    var upload_url = '/url/to/upload/file';
    /* post file request */
    $.ajaxFileUpload({
        url: upload_url,
        data: post_data,
        secureuri: false,
        fileElementId: file_element_id,
        dataType: 'json',
        success: function(data, status) {
            /* data 即为 ajax 请求返回的 json */
            if(data.rtn != 0) {
                alert(data.msg);
            } else  {
                /* do something */
            }
        },
        error: function (data, status, e) {
            alert(e);
        }
    });

    return false;
});

库代码

直接贴代码了。懒得研究 farbox 怎么传文件了。有空把博客迁走了。

;jQuery.extend({
    handleError: function( s, xhr, status, e ) {
        /* for jQuery compatibility */
        if ( s.error ) {
            s.error.call( s.context || s, xhr, status, e );
        }
        if ( s.global ) {
            (s.context ? jQuery(s.context) : jQuery.event).trigger( "ajaxError", [xhr, s, e] );
        }
    },

    createUploadIframe: function(id, uri) {
        /* create frame */
        var frameId = 'jUploadFrame' + id;
        var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"';
        if (window.ActiveXObject) {
            if(typeof uri== 'boolean') {
                iframeHtml += ' src="' + 'javascript:false' + '"';
            }
            else if(typeof uri== 'string') {
                iframeHtml += ' src="' + uri + '"';
            }
        }
        iframeHtml += ' />';
        jQuery(iframeHtml).appendTo(document.body);

        return jQuery('#' + frameId).get(0);
    },
    createUploadForm: function(id, fileElementId, data) {
        /* create form */
        var formId = 'jUploadForm' + id;
        var fileId = 'jUploadFile' + id;
        var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');
        if(data) {
            for(var i in data) {
                jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);
            }
        }
        var oldElement = jQuery('#' + fileElementId);
        var newElement = jQuery(oldElement).clone();
        jQuery(oldElement).attr('id', fileId);
        jQuery(oldElement).before(newElement);
        jQuery(oldElement).appendTo(form);

        /* set attributes */
        jQuery(form).css('position', 'absolute');
        jQuery(form).css('top', '-1200px');
        jQuery(form).css('left', '-1200px');
        jQuery(form).appendTo('body');
        return form;
    },

    ajaxFileUpload: function(s) {
        /* TODO introduce global settings, allowing the client to modify them for all requests, not only timeout */
        s = jQuery.extend({}, jQuery.ajaxSettings, s);
        var id = new Date().getTime()
        var form = jQuery.createUploadForm(id, s.fileElementId, (typeof(s.data)=='undefined'?false:s.data));
        var io = jQuery.createUploadIframe(id, s.secureuri);
        var frameId = 'jUploadFrame' + id;
        var formId = 'jUploadForm' + id;
        /* Watch for a new set of requests */
        if ( s.global && ! jQuery.active++ ) {
            jQuery.event.trigger( "ajaxStart" );
        }
        var requestDone = false;
        /* Create the request object */
        var xml = {}
        if ( s.global )
            jQuery.event.trigger("ajaxSend", [xml, s]);
        /* Wait for a response to come back */
        var uploadCallback = function(isTimeout) {
            var io = document.getElementById(frameId);
            try {
                if(io.contentWindow) {
                     xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
                     xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;

                } else if(io.contentDocument) {
                     xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
                    xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
                }
            } catch(e) {
                jQuery.handleError(s, xml, null, e);
            }
            if ( xml || isTimeout == "timeout") {
                requestDone = true;
                var status;
                try {
                    status = isTimeout != "timeout" ? "success" : "error";
                    /* Make sure that the request was successful or notmodified */
                    if ( status != "error" ) {
                        /* process the data (runs the xml through httpData regardless of callback) */
                        var data = jQuery.uploadHttpData( xml, s.dataType );
                        /* If a local callback was specified, fire it and pass it the data */
                        if ( s.success )
                            s.success( data, status );

                        /* Fire the global callback */
                        if( s.global )
                            jQuery.event.trigger( "ajaxSuccess", [xml, s] );
                    } else {
                        jQuery.handleError(s, xml, status);
                    }
                } catch(e) {
                    status = "error";
                    jQuery.handleError(s, xml, status, e);
                }

                /* The request was completed */
                if( s.global )
                    jQuery.event.trigger( "ajaxComplete", [xml, s] );

                /* Handle the global AJAX counter */
                if ( s.global && ! --jQuery.active )
                    jQuery.event.trigger( "ajaxStop" );

                /* Process result */
                if ( s.complete )
                    s.complete(xml, status);

                jQuery(io).unbind()

                setTimeout(function() {
                    try {
                        jQuery(io).remove();
                        jQuery(form).remove();
                    } catch(e) {
                        jQuery.handleError(s, xml, null, e);
                    }
                }, 100)

                xml = null
            }
        }
        /* Timeout checker */
        if ( s.timeout > 0 ) {
            setTimeout(function() {
                /* Check to see if the request is still happening */
                if( !requestDone ) uploadCallback( "timeout" );
            }, s.timeout);
        }
        try {
            var form = jQuery('#' + formId);
            jQuery(form).attr('action', s.url);
            jQuery(form).attr('method', 'POST');
            jQuery(form).attr('target', frameId);
            if(form.encoding) {
                jQuery(form).attr('encoding', 'multipart/form-data');
            }
            else {
                jQuery(form).attr('enctype', 'multipart/form-data');
            }
            jQuery(form).submit();

        } catch(e) {
            jQuery.handleError(s, xml, null, e);
        }

        jQuery('#' + frameId).load(uploadCallback   );
        return {abort: function () {}};
    },

    uploadHttpData: function( r, type ) {
        var data = !type;
        data = type == "xml" || data ? r.responseXML : r.responseText;
        /* If the type is "script", eval it in global context */
        if ( type == "script" )
            jQuery.globalEval( data );
        /* Get the JavaScript object, if JSON is used. */
        if ( type == "json" )
            data = r.responseText;
        var start = data.indexOf(">");
        if (start != -1) {
            var end = data.indexOf("<", start + 1);
            if (end != -1) {
                data = data.substring(start + 1, end);
            }
        }
        eval( "data = " + data );
        /* evaluate scripts within html */
        if ( type == "html" )
            jQuery("<div>").html(data).evalScripts();

        return data;
    }
})

结语

这个没啥好说的。就是贴代码。

【完】

ottocho 2013.11.05


Til next time,
at 08:22

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