iframe和DataForm

 一、iframe使用

iframe在一个页面中，相当于整个window窗口的子窗口，可通过页面的元素结构查看。

<div>
    <p>学习iframe</p>
    <form id='form' action="ajax1" method="post" target="ifra">
        <input type="text">
        <input type="button" value="提交" class="btn" onclick="ajaxSubmit5()">
    </form>
    <iframe id="iframe" name="ifra" style="height: 100px;width: 250px;" ></iframe>
</div>
……
function ajaxSubmit5() {
    document.getElementById('iframe').onload = reloadIframe;
    $('#form').submit();
}

function reloadIframe() {
    //ret = this.contentWindow.document.body.innerText
    ret = $(this).contents().find('body').text()
    data = JSON.parse(ret)
    if (data.status == 'success')
        alert('welcome')
}

def ajax1(request):
    print(request.GET)
    print(request.POST)
    print(request.body)
    ret = {'status':'success','data':[1,'hello']}
    return HttpResponse(json.dumps(ret))

执行过程：

①在输入框输入内容并点击提交，执行ajaxSubmit5()，并通过submit()向后台提交数据；

②由于在form表单中设置了target="ifra"，即target为iframe的name值，因此后台HttpResponse的返回值传递给iframe

③后台向iframe传递返回值时，即onload触发reloadIframe()

④在reloadIframe()中，通过this.contentWindow.document.body.innerText获取iframe的显示内容，即HttpResponse的返回值，再进行判断。

      

二、利用iframe+form上传文件

<form id='form1' action="ajax1" method="post" target="ifra1" enctype="multipart/form-data">
    <input type="text" name="k1">
    <input type="text" name="k2">
    <input type="file" name="k3">
    <input type="button" value="提交" class="btn" onclick="ajaxSubmit8()">
</form>
<iframe id="iframe1" name="ifra1" style="display: none;"></iframe>

function ajaxSubmit8() {
    $('#form1').submit();
    document.getElementById('iframe1').onload = reloadIframe1;
}
        
function reloadIframe1() {
    ret = this.contentWindow.document.body.innerHTML
    data = JSON.parse(ret)
    if (data.status == 'success')
        alert('welcome')
}

def ajax1(request):
    print(request.POST)
    print(request.FILES)
    obj = request.FILES.get('k3')
    file_path = os.path.join('static', obj.name)
    with open(file_path, 'wb') as f:
        for line in obj.chunks():
            f.write(line)
    ret = {'status':'success','data':[1,'hello']}
    return HttpResponse(json.dumps(ret))

三、利用ajax+FormData上传文件

<input type="file" id="img">
<input type="button" class="btn" value="提交" onclick="ajaxSubmit6()">
<input type="button" class="btn" value="提交" onclick="ajaxSubmit7()">
……

function ajaxSubmit6() {
    var data = new FormData()  //使用FormData时,需要在ajax中添加processData和contentType两个参数
    data.append('k1','v1')
    data.append('k2','v2')
    f = $('#img')[0].files[0]
    data.append('k3',f)
    $.ajax({
        url:'ajax1',
        type:'POST',
        data:data,
        processData:false,
        contentType:false,
        success:function (arg) {
            console.log(arg)
        }
    })
}

function ajaxSubmit7() {
    var data = new FormData()
    //使用FormData来传递数据时，无论是使用jQuery还是原生的XMLHttpRequest，都不能在后台使用request.body，数据在request.POST和request.FILES中
    data.append('k1','v1')
    data.append('k2','v2')
    f = $('#img')[0].files[0]
    data.append('k3',f)
    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function(){
        if(xhr.readyState == 4)
            console.log(xhr.responseText);
    }
    xhr.open('POST','ajax1');
    xhr.send(data);
}

def ajax1(request):
    print(request.POST)
    print(request.FILES)
    obj = request.FILES.get('k3')
    file_path = os.path.join('static', obj.name)
    with open(file_path, 'wb') as f:
        for line in obj.chunks():
            f.write(line)
    ret = {'status':'success','data':[1,'hello']}
    return HttpResponse(json.dumps(ret))

 四、利用iframe+form上传并生成图片预览

<form id='form1' action="upload_file" method="post" target="ifra1" enctype="multipart/form-data">
    <input type="file" name="k3" onchange="uploadFile()">
</form>
<iframe id="iframe1" name="ifra1" style="display: none;"></iframe>
<div>预览</div>
<div id="preview"></div>

def upload_file(req):
    if req.method == 'GET':
        return render(req,'upload.html')
    else:
        ret = {'status': True, 'data': None, 'message': None}
        obj = req.FILES.get('k3')
        nid = str(uuid.uuid4())
        file_path = os.path.join('static', nid + obj.name)
        with open(file_path, 'wb') as f:
            for line in obj.chunks():
                f.write(line)
        ret['data'] = file_path
        return HttpResponse(json.dumps(ret))

<script src="/static/jquery-3.3.1.min.js"></script>
<script>
    function uploadFile() {
        document.getElementById('iframe1').onload = reloadIframe1;
            $('#form1').submit();
    }
        
function reloadIframe1() {
    ret = this.contentWindow.document.body.innerHTML
    obj = JSON.parse(ret)
    console.log(obj)
    var tag = document.createElement('img')  //创建img标签
    tag.src = obj.data   //设置img标签的src为本地已上传图片的路径
    $('#preview').empty().append(tag)  //清空预览图片并上传新的图片
}
</script>