node webkit: export data to csv and prompt the user to save the file

问题

I could implement the export data to csv on node webkit with node fs modules. But now I want to prompt the user to save the file in his/her desired location. Like the download pop-up in case of html. I tried doing on the lines of this code and even this file dialog. Could someone help me find a way out of this. Here's my code.

fs.writeFile("export.csv", data, function(err) {
    if(err) {
       console.log(err);
    } else {
        $('#export_file').show();
        $('#export_file input').on('change', function (event) {
            console.log($(this).val());
            console.log("The file was saved!");
        });
    }
});

<div id="export_file" style="display:none">
    <input type="file" nwsaveas nwworkingdir="/data/input/" />
</div>

回答1:

I found a solution here http://9ijy.net/blog/view/6

Step 1 In your html file, add a Input tag block like below:

<input id="export_file" type="file" nwsaveas style="display:none" nwworkingdir=""/>

Step 2 Add a new function in your javascript file like below:

function saveFile(name,data) {
    var chooser = document.querySelector(name);
    chooser.addEventListener("change", function(evt) {
      console.log(this.value); // get your file name
     var fs = require('fs');// save it now
fs.writeFile(this.value, data, function(err) {
    if(err) {
       alert("error"+err);
    }
});
    }, false);

    chooser.click();  
  }

Step 3 Save your file where ever you like by using saveFile(name,data) function like below:

...

_exportCSV="you data to save";

saveFile('#export_file',_exportCSV);

回答2:

You are writing the file dialog code as a callback to fs.writeFile. A callback means it will be called AFTER the file is saved. This is what might be happening right now. 1) File is written in the current directory where node-webkit app is running from. 2) When the file is saved without any errors, the dialog shows up. But this dialog is of no help.
Instead, show the dialog earlier and get the file-path from it(https://github.com/rogerwang/node-webkit/wiki/File-dialogs). Pass this path as the first arg in fs.writeFile(). Done.

来源：https://stackoverflow.com/questions/20609605/node-webkit-export-data-to-csv-and-prompt-the-user-to-save-the-file

标签

javascript

node.js

node-webkit