Save A Field Value To A File On Desktop

I am developing a custom application in 'ServiceNow' which requires Javascript and HTML coding. So, I have a field say, 'description' on my form. How may I save this field's value

Solution 1:

While JavaScript cannot create a file for you to download by itself, ServiceNow does have a way for you to create one. Creating a Word document is impossible without the use of a MID server and some custom Java code, but if any file type will do you can create an Excel file using an export URL. To test this out, I made a UI Action in a developer instance running Helsinki on the Problem table. I made a list view that contains only the field that I wanted to save, and then used the following code in the UI action:

functionstartDownload() {
    window.open("https://dev13274.service-now.com/problem_list.do?EXCEL&sysparm_query=sys_id%3D" + 
        g_form.getUniqueValue() + "&sysparm_first_row=1&sysparm_view=download");
}

When the UI action is used, it opens a new tab that will close almost immediately and prompt the user to save or open an Excel file that contains the contents of that single field.

If you want to know more about the different ways you can export data from ServiceNow, check their wiki-page on the subject.

Solution 2:

You can use the HTML5 FileSystem API to achieve that

window.requestFileSystem(window.PERSISTENT, 1024*1024, function (fs) {
  fs.root.getFile('file.txt', {create: true}, function(fileEntry) {
    fileEntry.createWriter(function(fileWriter) {
      var blob = newBlob([description.value], {type: 'text/plain'});
      fileWriter.write(blob);
    });
  });
});

FYI, chrome supports webkitRequestFileSystem.

Alternatively, use a Blob and generate download link

var text = document.getElementById("description").value;
var blob = newBlob([text], {type:'text/plain'});
var fileName = "test.txt";

var downloadLink = document.createElement("a");
downloadLink.download = fileName;
downloadLink.href = window.webkitURL.createObjectURL(textFile);
downloadLink.click();

Solution 3:

Javascript protects clients against malicious servers who would want to read files on their computer. For that reason, you cannot read or write a file to the client's computer with javascript UNLESS you use some kind of file upload control that implicitely asks for the user's permission.