Barra de progresso de upload de arquivo com jQuery

Estou tentando implementar um recurso de upload de arquivo AJAX no meu projeto. Eu estou usando jQuery para isso; meu código envia os dados usando AJAX. Também quero implementar uma barra de progresso de upload de arquivo. Como posso fazer isso? Existe alguma maneira de calcular quanto já foi enviado para que eu possa calcular a porcentagem de upload e criar uma barra de progresso?

Nota: Esta pergunta está relacionada ao plug-in de formulário jQuery . Se você estiver procurando por uma solução jQuery pura, comece aqui . Não existe uma solução jQuery geral para todos os navegadores. Então você tem que usar um plugin. Estou usando o dropzone.js , que tem um fallback fácil para navegadores mais antigos. Qual plugin você prefere depende de suas necessidades. Há muitas boas comparações postadas por aí.

Dos exemplos :

jQuery:

$(function() {

    var bar = $('.bar');
    var percent = $('.percent');
    var status = $('#status');

    $('form').ajaxForm({
        beforeSend: function() {
            status.empty();
            var percentVal = '0%';
            bar.width(percentVal);
            percent.html(percentVal);
        },
        uploadProgress: function(event, position, total, percentComplete) {
            var percentVal = percentComplete + '%';
            bar.width(percentVal);
            percent.html(percentVal);
        },
        complete: function(xhr) {
            status.html(xhr.responseText);
        }
    });
}); 

html:

<form action="file-echo2.php" method="post" enctype="multipart/form-data">
    <input type="file" name="myfile"><br>
    <input type="submit" value="Upload File to Server">
</form>

<div class="progress">
    <div class="bar"></div >
    <div class="percent">0%</div >
</div>

<div id="status"></div>

você tem que estilizar a barra de progresso com css ...

Eu fiz isso apenas com jQuery:

$.ajax({
  xhr: function() {
    var xhr = new window.XMLHttpRequest();

    xhr.upload.addEventListener("progress", function(evt) {
      if (evt.lengthComputable) {
        var percentComplete = evt.loaded / evt.total;
        percentComplete = parseInt(percentComplete * 100);
        console.log(percentComplete);

        if (percentComplete === 100) {

        }

      }
    }, false);

    return xhr;
  },
  url: posturlfile,
  type: "POST",
  data: JSON.stringify(fileuploaddata),
  contentType: "application/json",
  dataType: "json",
  success: function(result) {
    console.log(result);
  }
});

Eu usei o seguinte no meu projeto. você pode tentar também.

ajax = new XMLHttpRequest();
ajax.onreadystatechange = function () {

    if (ajax.status) {

        if (ajax.status == 200 && (ajax.readyState == 4)){
            //To do tasks if any, when upload is completed
        }
    }
}
ajax.upload.addEventListener("progress", function (event) {

    var percent = (event.loaded / event.total) * 100;
    //**percent** variable can be used for modifying the length of your progress bar.
    console.log(percent);

});

ajax.open("POST", 'your file upload link', true);
ajax.send(formData);
//ajax.send is for uploading form data.

verifique isto: http://hayageek.com/docs/jquery-upload-file.php Encontrei-o acidentalmente na rede.

Se você estiver usando jquery no seu projeto e não quiser implementar o mecanismo de upload do zero, poderá usar https://github.com/blueimp/jQuery-File-Upload .

Eles têm uma API muito boa com seleção múltipla de arquivos, suporte a arrastar e soltar, barra de progresso, validação e pré-visualização de imagens, suporte a vários domínios, uploads de arquivos em pedaços e recuperáveis. E eles têm scripts de amostra para vários idiomas do servidor (nó, php, python e pronto).

URL da demonstração: https://blueimp.github.io/jQuery-File-Upload/ .

Aqui está um uso mais completo do jquery 1.11.x $ .ajax ():

<script type="text/javascript">
    function uploadProgressHandler(event) {
        $("#loaded_n_total").html("Uploaded " + event.loaded + " bytes of " + event.total);
        var percent = (event.loaded / event.total) * 100;
        var progress = Math.round(percent);
        $("#uploadProgressBar").html(progress + " percent na ang progress");
        $("#uploadProgressBar").css("width", progress + "%");
        $("#status").html(progress + "% uploaded... please wait");
    }

    function loadHandler(event) {
        $("#status").html(event.target.responseText);
        $("#uploadProgressBar").css("width", "0%");
    }

    function errorHandler(event) {
        $("#status").html("Upload Failed");
    }

    function abortHandler(event) {
        $("#status").html("Upload Aborted");
    }

    $("#uploadFile").click(function (event) {
        event.preventDefault();
        var file = $("#fileUpload")[0].files[0];
        var formData = new FormData();
        formData.append("file1", file);

        $.ajax({
            url: 'http://testarea.local/UploadWithProgressBar1/file_upload_parser.php',
            method: 'POST',
            type: 'POST',
            data: formData,
            contentType: false,
            processData: false,
            xhr: function () {
                var xhr = new window.XMLHttpRequest();
                xhr.upload.addEventListener("progress",
                    uploadProgressHandler,
                    false
                );
                xhr.addEventListener("load", loadHandler, false);
                xhr.addEventListener("error", errorHandler, false);
                xhr.addEventListener("abort", abortHandler, false);

                return xhr;
            }
        });
    });
</script>

Isso resolveu meu problema

$.ajax({
  xhr: function() {
    var xhr = new window.XMLHttpRequest();

    xhr.upload.addEventListener("progress", function(evt) {
      if (evt.lengthComputable) {
        var percentComplete = evt.loaded / evt.total;
        percentComplete = parseInt(percentComplete * 100);
var $link = $('.'+ids);
          var $img = $link.find('i'); 
          $link.html('Uploading..('+percentComplete+'%)');
          $link.append($img);
      }
    }, false);

    return xhr;
  },
  url: posturlfile,
  type: "POST",
  data: JSON.stringify(fileuploaddata),
  contentType: "application/json",
  dataType: "json",
  success: function(result) {
    console.log(result);
  }
});

A resposta de Kathir é ótima, pois ele resolve esse problema com apenas o jQuery. Eu só queria fazer algumas adições à sua resposta para trabalhar seu código com uma bela barra de progresso HTML:

$.ajax({
xhr: function() {
var xhr = new window.XMLHttpRequest();

xhr.upload.addEventListener("progress", function(evt) {
  if (evt.lengthComputable) {
    var percentComplete = evt.loaded / evt.total;
    percentComplete = parseInt(percentComplete * 100);

    $('.progress-bar').width(percentComplete+'%');
    $('.progress-bar').html(percentComplete+'%');

  }
}, false);

return xhr;
},
url: posturlfile,
type: "POST",
data: JSON.stringify(fileuploaddata),
contentType: "application/json",
dataType: "json",
success: function(result) {
console.log(result);
}
});

Aqui está o código HTML da barra de progresso, usei o Bootstrap 3 para o elemento da barra de progresso:

<div class="progress" style="display:none;">
<div class="progress-bar progress-bar-success progress-bar-striped 
active" role="progressbar"
aria-valuemin="0" aria-valuemax="100" style="width:0%">
0%
</div>
</div>

JavaScript:

<script>
/* jquery.form.min.js */
(function(e){"use strict";if(typeof define==="function"&&define.amd){define(["jquery"],e)}else{e(typeof jQuery!="undefined"?jQuery:window.Zepto)}})(function(e){"use strict";function r(t){var n=t.data;if(!t.isDefaultPrevented()){t.preventDefault();e(t.target).ajaxSubmit(n)}}function i(t){var n=t.target;var r=e(n);if(!r.is("[type=submit],[type=image]")){var i=r.closest("[type=submit]");if(i.length===0){return}n=i[0]}var s=this;s.clk=n;if(n.type=="image"){if(t.offsetX!==undefined){s.clk_x=t.offsetX;s.clk_y=t.offsetY}else if(typeof e.fn.offset=="function"){var o=r.offset();s.clk_x=t.pageX-o.left;s.clk_y=t.pageY-o.top}else{s.clk_x=t.pageX-n.offsetLeft;s.clk_y=t.pageY-n.offsetTop}}setTimeout(function(){s.clk=s.clk_x=s.clk_y=null},100)}function s(){if(!e.fn.ajaxSubmit.debug){return}var t="[jquery.form] "+Array.prototype.join.call(arguments,"");if(window.console&&window.console.log){window.console.log(t)}else if(window.opera&&window.opera.postError){window.opera.postError(t)}}var t={};t.fileapi=e("<input type='file'/>").get(0).files!==undefined;t.formdata=window.FormData!==undefined;var n=!!e.fn.prop;e.fn.attr2=function(){if(!n){return this.attr.apply(this,arguments)}var e=this.prop.apply(this,arguments);if(e&&e.jquery||typeof e==="string"){return e}return this.attr.apply(this,arguments)};e.fn.ajaxSubmit=function(r){function k(t){var n=e.param(t,r.traditional).split("&");var i=n.length;var s=[];var o,u;for(o=0;o<i;o++){n[o]=n[o].replace(/\+/g," ");u=n[o].split("=");s.push([decodeURIComponent(u[0]),decodeURIComponent(u[1])])}return s}function L(t){var n=new FormData;for(var s=0;s<t.length;s++){n.append(t[s].name,t[s].value)}if(r.extraData){var o=k(r.extraData);for(s=0;s<o.length;s++){if(o[s]){n.append(o[s][0],o[s][1])}}}r.data=null;var u=e.extend(true,{},e.ajaxSettings,r,{contentType:false,processData:false,cache:false,type:i||"POST"});if(r.uploadProgress){u.xhr=function(){var t=e.ajaxSettings.xhr();if(t.upload){t.upload.addEventListener("progress",function(e){var t=0;var n=e.loaded||e.position;var i=e.total;if(e.lengthComputable){t=Math.ceil(n/i*100)}r.uploadProgress(e,n,i,t)},false)}return t}}u.data=null;var a=u.beforeSend;u.beforeSend=function(e,t){if(r.formData){t.data=r.formData}else{t.data=n}if(a){a.call(this,e,t)}};return e.ajax(u)}function A(t){function T(e){var t=null;try{if(e.contentWindow){t=e.contentWindow.document}}catch(n){s("cannot get iframe.contentWindow document: "+n)}if(t){return t}try{t=e.contentDocument?e.contentDocument:e.document}catch(n){s("cannot get iframe.contentDocument: "+n);t=e.document}return t}function k(){function f(){try{var e=T(v).readyState;s("state = "+e);if(e&&e.toLowerCase()=="uninitialized"){setTimeout(f,50)}}catch(t){s("Server abort: ",t," (",t.name,")");_(x);if(w){clearTimeout(w)}w=undefined}}var t=a.attr2("target"),n=a.attr2("action"),r="multipart/form-data",u=a.attr("enctype")||a.attr("encoding")||r;o.setAttribute("target",p);if(!i||/post/i.test(i)){o.setAttribute("method","POST")}if(n!=l.url){o.setAttribute("action",l.url)}if(!l.skipEncodingOverride&&(!i||/post/i.test(i))){a.attr({encoding:"multipart/form-data",enctype:"multipart/form-data"})}if(l.timeout){w=setTimeout(function(){b=true;_(S)},l.timeout)}var c=[];try{if(l.extraData){for(var h in l.extraData){if(l.extraData.hasOwnProperty(h)){if(e.isPlainObject(l.extraData[h])&&l.extraData[h].hasOwnProperty("name")&&l.extraData[h].hasOwnProperty("value")){c.push(e('<input type="hidden" name="'+l.extraData[h].name+'">').val(l.extraData[h].value).appendTo(o)[0])}else{c.push(e('<input type="hidden" name="'+h+'">').val(l.extraData[h]).appendTo(o)[0])}}}}if(!l.iframeTarget){d.appendTo("body")}if(v.attachEvent){v.attachEvent("onload",_)}else{v.addEventListener("load",_,false)}setTimeout(f,15);try{o.submit()}catch(m){var g=document.createElement("form").submit;g.apply(o)}}finally{o.setAttribute("action",n);o.setAttribute("enctype",u);if(t){o.setAttribute("target",t)}else{a.removeAttr("target")}e(c).remove()}}function _(t){if(m.aborted||M){return}A=T(v);if(!A){s("cannot access response document");t=x}if(t===S&&m){m.abort("timeout");E.reject(m,"timeout");return}else if(t==x&&m){m.abort("server abort");E.reject(m,"error","server abort");return}if(!A||A.location.href==l.iframeSrc){if(!b){return}}if(v.detachEvent){v.detachEvent("onload",_)}else{v.removeEventListener("load",_,false)}var n="success",r;try{if(b){throw"timeout"}var i=l.dataType=="xml"||A.XMLDocument||e.isXMLDoc(A);s("isXml="+i);if(!i&&window.opera&&(A.body===null||!A.body.innerHTML)){if(--O){s("requeing onLoad callback, DOM not available");setTimeout(_,250);return}}var o=A.body?A.body:A.documentElement;m.responseText=o?o.innerHTML:null;m.responseXML=A.XMLDocument?A.XMLDocument:A;if(i){l.dataType="xml"}m.getResponseHeader=function(e){var t={"content-type":l.dataType};return t[e.toLowerCase()]};if(o){m.status=Number(o.getAttribute("status"))||m.status;m.statusText=o.getAttribute("statusText")||m.statusText}var u=(l.dataType||"").toLowerCase();var a=/(json|script|text)/.test(u);if(a||l.textarea){var f=A.getElementsByTagName("textarea")[0];if(f){m.responseText=f.value;m.status=Number(f.getAttribute("status"))||m.status;m.statusText=f.getAttribute("statusText")||m.statusText}else if(a){var c=A.getElementsByTagName("pre")[0];var p=A.getElementsByTagName("body")[0];if(c){m.responseText=c.textContent?c.textContent:c.innerText}else if(p){m.responseText=p.textContent?p.textContent:p.innerText}}}else if(u=="xml"&&!m.responseXML&&m.responseText){m.responseXML=D(m.responseText)}try{L=H(m,u,l)}catch(g){n="parsererror";m.error=r=g||n}}catch(g){s("error caught: ",g);n="error";m.error=r=g||n}if(m.aborted){s("upload aborted");n=null}if(m.status){n=m.status>=200&&m.status<300||m.status===304?"success":"error"}if(n==="success"){if(l.success){l.success.call(l.context,L,"success",m)}E.resolve(m.responseText,"success",m);if(h){e.event.trigger("ajaxSuccess",[m,l])}}else if(n){if(r===undefined){r=m.statusText}if(l.error){l.error.call(l.context,m,n,r)}E.reject(m,"error",r);if(h){e.event.trigger("ajaxError",[m,l,r])}}if(h){e.event.trigger("ajaxComplete",[m,l])}if(h&&!--e.active){e.event.trigger("ajaxStop")}if(l.complete){l.complete.call(l.context,m,n)}M=true;if(l.timeout){clearTimeout(w)}setTimeout(function(){if(!l.iframeTarget){d.remove()}else{d.attr("src",l.iframeSrc)}m.responseXML=null},100)}var o=a[0],u,f,l,h,p,d,v,m,g,y,b,w;var E=e.Deferred();E.abort=function(e){m.abort(e)};if(t){for(f=0;f<c.length;f++){u=e(c[f]);if(n){u.prop("disabled",false)}else{u.removeAttr("disabled")}}}l=e.extend(true,{},e.ajaxSettings,r);l.context=l.context||l;p="jqFormIO"+(new Date).getTime();if(l.iframeTarget){d=e(l.iframeTarget);y=d.attr2("name");if(!y){d.attr2("name",p)}else{p=y}}else{d=e('<iframe name="'+p+'" src="'+l.iframeSrc+'" />');d.css({position:"absolute",top:"-1000px",left:"-1000px"})}v=d[0];m={aborted:0,responseText:null,responseXML:null,status:0,statusText:"n/a",getAllResponseHeaders:function(){},getResponseHeader:function(){},setRequestHeader:function(){},abort:function(t){var n=t==="timeout"?"timeout":"aborted";s("aborting upload... "+n);this.aborted=1;try{if(v.contentWindow.document.execCommand){v.contentWindow.document.execCommand("Stop")}}catch(r){}d.attr("src",l.iframeSrc);m.error=n;if(l.error){l.error.call(l.context,m,n,t)}if(h){e.event.trigger("ajaxError",[m,l,n])}if(l.complete){l.complete.call(l.context,m,n)}}};h=l.global;if(h&&0===e.active++){e.event.trigger("ajaxStart")}if(h){e.event.trigger("ajaxSend",[m,l])}if(l.beforeSend&&l.beforeSend.call(l.context,m,l)===false){if(l.global){e.active--}E.reject();return E}if(m.aborted){E.reject();return E}g=o.clk;if(g){y=g.name;if(y&&!g.disabled){l.extraData=l.extraData||{};l.extraData[y]=g.value;if(g.type=="image"){l.extraData[y+".x"]=o.clk_x;l.extraData[y+".y"]=o.clk_y}}}var S=1;var x=2;var N=e("meta[name=csrf-token]").attr("content");var C=e("meta[name=csrf-param]").attr("content");if(C&&N){l.extraData=l.extraData||{};l.extraData[C]=N}if(l.forceSync){k()}else{setTimeout(k,10)}var L,A,O=50,M;var D=e.parseXML||function(e,t){if(window.ActiveXObject){t=new ActiveXObject("Microsoft.XMLDOM");t.async="false";t.loadXML(e)}else{t=(new DOMParser).parseFromString(e,"text/xml")}return t&&t.documentElement&&t.documentElement.nodeName!="parsererror"?t:null};var P=e.parseJSON||function(e){return window["eval"]("("+e+")")};var H=function(t,n,r){var i=t.getResponseHeader("content-type")||"",s=n==="xml"||!n&&i.indexOf("xml")>=0,o=s?t.responseXML:t.responseText;if(s&&o.documentElement.nodeName==="parsererror"){if(e.error){e.error("parsererror")}}if(r&&r.dataFilter){o=r.dataFilter(o,n)}if(typeof o==="string"){if(n==="json"||!n&&i.indexOf("json")>=0){o=P(o)}else if(n==="script"||!n&&i.indexOf("javascript")>=0){e.globalEval(o)}}return o};return E}if(!this.length){s("ajaxSubmit: skipping submit process - no element selected");return this}var i,o,u,a=this;if(typeof r=="function"){r={success:r}}else if(r===undefined){r={}}i=r.type||this.attr2("method");o=r.url||this.attr2("action");u=typeof o==="string"?e.trim(o):"";u=u||window.location.href||"";if(u){u=(u.match(/^([^#]+)/)||[])[1]}r=e.extend(true,{url:u,success:e.ajaxSettings.success,type:i||e.ajaxSettings.type,iframeSrc:/^https/i.test(window.location.href||"")?"javascript:false":"about:blank"},r);var f={};this.trigger("form-pre-serialize",[this,r,f]);if(f.veto){s("ajaxSubmit: submit vetoed via form-pre-serialize trigger");return this}if(r.beforeSerialize&&r.beforeSerialize(this,r)===false){s("ajaxSubmit: submit aborted via beforeSerialize callback");return this}var l=r.traditional;if(l===undefined){l=e.ajaxSettings.traditional}var c=[];var h,p=this.formToArray(r.semantic,c);if(r.data){r.extraData=r.data;h=e.param(r.data,l)}if(r.beforeSubmit&&r.beforeSubmit(p,this,r)===false){s("ajaxSubmit: submit aborted via beforeSubmit callback");return this}this.trigger("form-submit-validate",[p,this,r,f]);if(f.veto){s("ajaxSubmit: submit vetoed via form-submit-validate trigger");return this}var d=e.param(p,l);if(h){d=d?d+"&"+h:h}if(r.type.toUpperCase()=="GET"){r.url+=(r.url.indexOf("?")>=0?"&":"?")+d;r.data=null}else{r.data=d}var v=[];if(r.resetForm){v.push(function(){a.resetForm()})}if(r.clearForm){v.push(function(){a.clearForm(r.includeHidden)})}if(!r.dataType&&r.target){var m=r.success||function(){};v.push(function(t){var n=r.replaceTarget?"replaceWith":"html";e(r.target)[n](t).each(m,arguments)})}else if(r.success){v.push(r.success)}r.success=function(e,t,n){var i=r.context||this;for(var s=0,o=v.length;s<o;s++){v[s].apply(i,[e,t,n||a,a])}};if(r.error){var g=r.error;r.error=function(e,t,n){var i=r.context||this;g.apply(i,[e,t,n,a])}}if(r.complete){var y=r.complete;r.complete=function(e,t){var n=r.context||this;y.apply(n,[e,t,a])}}var b=e("input[type=file]:enabled",this).filter(function(){return e(this).val()!==""});var w=b.length>0;var E="multipart/form-data";var S=a.attr("enctype")==E||a.attr("encoding")==E;var x=t.fileapi&&t.formdata;s("fileAPI :"+x);var T=(w||S)&&!x;var N;if(r.iframe!==false&&(r.iframe||T)){if(r.closeKeepAlive){e.get(r.closeKeepAlive,function(){N=A(p)})}else{N=A(p)}}else if((w||S)&&x){N=L(p)}else{N=e.ajax(r)}a.removeData("jqxhr").data("jqxhr",N);for(var C=0;C<c.length;C++){c[C]=null}this.trigger("form-submit-notify",[this,r]);return this};e.fn.ajaxForm=function(t){t=t||{};t.delegation=t.delegation&&e.isFunction(e.fn.on);if(!t.delegation&&this.length===0){var n={s:this.selector,c:this.context};if(!e.isReady&&n.s){s("DOM not ready, queuing ajaxForm");e(function(){e(n.s,n.c).ajaxForm(t)});return this}s("terminating; zero elements found by selector"+(e.isReady?"":" (DOM not ready)"));return this}if(t.delegation){e(document).off("submit.form-plugin",this.selector,r).off("click.form-plugin",this.selector,i).on("submit.form-plugin",this.selector,t,r).on("click.form-plugin",this.selector,t,i);return this}return this.ajaxFormUnbind().bind("submit.form-plugin",t,r).bind("click.form-plugin",t,i)};e.fn.ajaxFormUnbind=function(){return this.unbind("submit.form-plugin click.form-plugin")};e.fn.formToArray=function(n,r){var i=[];if(this.length===0){return i}var s=this[0];var o=this.attr("id");var u=n?s.getElementsByTagName("*"):s.elements;var a;if(u&&!/MSIE [678]/.test(navigator.userAgent)){u=e(u).get()}if(o){a=e(':input[form="'+o+'"]').get();if(a.length){u=(u||[]).concat(a)}}if(!u||!u.length){return i}var f,l,c,h,p,d,v;for(f=0,d=u.length;f<d;f++){p=u[f];c=p.name;if(!c||p.disabled){continue}if(n&&s.clk&&p.type=="image"){if(s.clk==p){i.push({name:c,value:e(p).val(),type:p.type});i.push({name:c+".x",value:s.clk_x},{name:c+".y",value:s.clk_y})}continue}h=e.fieldValue(p,true);if(h&&h.constructor==Array){if(r){r.push(p)}for(l=0,v=h.length;l<v;l++){i.push({name:c,value:h[l]})}}else if(t.fileapi&&p.type=="file"){if(r){r.push(p)}var m=p.files;if(m.length){for(l=0;l<m.length;l++){i.push({name:c,value:m[l],type:p.type})}}else{i.push({name:c,value:"",type:p.type})}}else if(h!==null&&typeof h!="undefined"){if(r){r.push(p)}i.push({name:c,value:h,type:p.type,required:p.required})}}if(!n&&s.clk){var g=e(s.clk),y=g[0];c=y.name;if(c&&!y.disabled&&y.type=="image"){i.push({name:c,value:g.val()});i.push({name:c+".x",value:s.clk_x},{name:c+".y",value:s.clk_y})}}return i};e.fn.formSerialize=function(t){return e.param(this.formToArray(t))};e.fn.fieldSerialize=function(t){var n=[];this.each(function(){var r=this.name;if(!r){return}var i=e.fieldValue(this,t);if(i&&i.constructor==Array){for(var s=0,o=i.length;s<o;s++){n.push({name:r,value:i[s]})}}else if(i!==null&&typeof i!="undefined"){n.push({name:this.name,value:i})}});return e.param(n)};e.fn.fieldValue=function(t){for(var n=[],r=0,i=this.length;r<i;r++){var s=this[r];var o=e.fieldValue(s,t);if(o===null||typeof o=="undefined"||o.constructor==Array&&!o.length){continue}if(o.constructor==Array){e.merge(n,o)}else{n.push(o)}}return n};e.fieldValue=function(t,n){var r=t.name,i=t.type,s=t.tagName.toLowerCase();if(n===undefined){n=true}if(n&&(!r||t.disabled||i=="reset"||i=="button"||(i=="checkbox"||i=="radio")&&!t.checked||(i=="submit"||i=="image")&&t.form&&t.form.clk!=t||s=="select"&&t.selectedIndex==-1)){return null}if(s=="select"){var o=t.selectedIndex;if(o<0){return null}var u=[],a=t.options;var f=i=="select-one";var l=f?o+1:a.length;for(var c=f?o:0;c<l;c++){var h=a[c];if(h.selected){var p=h.value;if(!p){p=h.attributes&&h.attributes.value&&!h.attributes.value.specified?h.text:h.value}if(f){return p}u.push(p)}}return u}return e(t).val()};e.fn.clearForm=function(t){return this.each(function(){e("input,select,textarea",this).clearFields(t)})};e.fn.clearFields=e.fn.clearInputs=function(t){var n=/^(?:color|date|datetime|email|month|number|password|range|search|tel|text|time|url|week)$/i;return this.each(function(){var r=this.type,i=this.tagName.toLowerCase();if(n.test(r)||i=="textarea"){this.value=""}else if(r=="checkbox"||r=="radio"){this.checked=false}else if(i=="select"){this.selectedIndex=-1}else if(r=="file"){if(/MSIE/.test(navigator.userAgent)){e(this).replaceWith(e(this).clone(true))}else{e(this).val("")}}else if(t){if(t===true&&/hidden/.test(r)||typeof t=="string"&&e(this).is(t)){this.value=""}}})};e.fn.resetForm=function(){return this.each(function(){if(typeof this.reset=="function"||typeof this.reset=="object"&&!this.reset.nodeType){this.reset()}})};e.fn.enable=function(e){if(e===undefined){e=true}return this.each(function(){this.disabled=!e})};e.fn.selected=function(t){if(t===undefined){t=true}return this.each(function(){var n=this.type;if(n=="checkbox"||n=="radio"){this.checked=t}else if(this.tagName.toLowerCase()=="option"){var r=e(this).parent("select");if(t&&r[0]&&r[0].type=="select-one"){r.find("option").selected(false)}this.selected=t}})};e.fn.ajaxSubmit.debug=false})
</script>
    <script type="text/javascript">
        $(document).ready(function () {
            $('#myform').on('change', '.wpcf7-file', function (e) {
                e.preventDefault();
                var myParent = $(this).parent();
                var filname= $('input[type=file]').val()

                if (filname) { 
                $(this).parent().find('#progress-div').show();          
                $('#myform').ajaxSubmit({
                    // target: '#progress-div123',/**********only for response************/
                    beforeSubmit: function () {
                        myParent.find('#progress-bar').width('0%');
                    },
                    uploadProgress: function (event, position, total, percentComplete) {
                        myParent.find('#progress-bar').width(percentComplete + '%');
                        myParent.find('#progress-bar').html('<div id="progress-status">' + percentComplete + ' %</div>')
                    },
                    success: function showResponse(responseText, statusText, xhr, $form) {

                        //myParent.find('#progress-div').hide(10000);
                    },
                    resetForm: false
                });

                }
                return false;
            });


           /***********Error msg if file not valid***************/
                $('input[type=file]').change(function () {
                var val = $(this).val().toLowerCase();
                var regex = new RegExp("(.*?)\.(pdf|txt|jpg|png|doc|docx|xlx|xls|xlsx|jpg|ppt|pptx|tif|tiff|\n\
                bmp|pcd|gif|bmp|zip|rar|odt|avi|ogg|m4a|mov|mp3|mp4|mpg|wav|wmv|stp|sldprt|sldasm|iges|igs|stl|x_t|step\n\
                |stp|prt|asm|idw|iam|ipt|dxf|dwg|pdf|slddrw|dwf)$");
                if (!(regex.test(val))) {
                    $(this).val('');
                    alert('Please select correct file format');
                }
                });
            /*********End*****************/

        });
</script>

Estilos:

<style>
    body{width:610px;}
    #uploadForm {border-top:#F0F0F0 2px solid;background:#FAF8F8;padding:10px;}
    #uploadForm label {margin:2px; font-size:1em; font-weight:bold;}
    .demoInputBox{padding:5px; border:#F0F0F0 1px solid; border-radius:4px; background-color:#FFF;}
    #progress-bar {background-color: #12CC1A;height:20px;color: #FFFFFF;width:0%;-webkit-transition: width .3s;-moz-transition: width .3s;transition: width .3s;}
    .btnSubmit{background-color:#09f;border:0;padding:10px 40px;color:#FFF;border:#F0F0F0 1px solid; border-radius:4px;}
    #progress-div
    {
        border: 1px solid #0fa015;
        border-radius: 4px;
        margin: -35px 2px 7px 295px;
        padding: 5px 0;
        text-align: center;
        width: 277px;
    }

    #targetLayer{width:100%;text-align:center;}
</style>