Question

我使用fetch Web API从几个网址中检索文件内容并将其发送到表单。但是，当从表单POST ajax请求发送到后端时，我没有在那里使用实际的文件对象，而是检索Promise对象（无法在后端处理）。

下面的代码在发送到$ .ajax以获取File对象时阻止了infile和mapfile变量有什么问题？

    let formData = new FormData();

    let exampleb2pPromise = fetch( fileHash["infile"].fileURL).then(function(response) {
        fileHash["infile"].blob = response.blob();
        return fileHash;
    }).then(function(fileHash) {
        let infile = new File( [ fileHash["infile"].blob ], fileHash["infile"].filename, { type: fileHash["infile"].filetype } );
        return infile;
    });

    let exampleCSVPromise = fetch(fileHash["mapfile"].fileURL).then(function(response) { ...


    Promise.all([exampleb2pPromise, exampleCSVPromise]).then(function(values) {

            let infile = values[0];
            let mapfile = values[1];

            if ( infile && mapfile ) ) {

                console.log( infile );
                formData.append( "infile", infile, "input.tsv" );

                if ( mapfile ) {
                    console.log( mapfile );
                    formData.append( "mapfile", mapfile, "mapfile.txt" );
                }

            }

            return formData;

    }).then( function( formData ) {

        let exec = "/submit";

        console.log( formData );
        $.ajax({
            url : exec,
            type: "POST",
            data : formData,
            processData: false,
            contentType: false,
                success:function(data, textStatus, jqXHR){

                    if ( data && data.session ) {
                        ...

                    }

                },
                error: function(jqXHR, textStatus, errorThrown){
                    //if fails

                    // TODO: To be handled
                }
        });
    });

Answer 1

response.blob()返回Promise - 您需要重写代码

let exampleb2pPromise = fetch( fileHash["infile"].fileURL).then(function(response) {
    return response.blob();
}).then(function(blob) {
    fileHash["infile"].blob = blob;
    return fileHash;
}).then(function(fileHash) {
    let infile = new File( [ fileHash["infile"].blob ], fileHash["infile"].filename, { type: fileHash["infile"].filetype } );
    return infile;
});

虽然，编写它更容易：

let exampleb2pPromise = fetch( fileHash.infile.fileURL)
.then(response => response.blob())
.then(blob => new File(fileHash.infile.blob = blob, fileHash.infile.filename, { type: fileHash.infile.filetype } ));

POST表单请求后未解析与File对象的promise

1 个答案: