NsIFilePicker

Using nsIFilePicker

const nsIFilePicker = Components.interfaces.nsIFilePicker;

var fp = Components.classes["@mozilla.org/filepicker;1"]
	.createInstance(nsIFilePicker);
fp.init(window, "Dialog Title", nsIFilePicker.modeOpen);
fp.appendFilters(nsIFilePicker.filterAll | nsIFilePicker.filterText);

var rv = fp.show();
if (rv == nsIFilePicker.returnOK)
{
  var file = fp.file;
  // work with returned nsILocalFile...
}

Notes

• If you pass empty string as dialog title, the dialog will have default title
• When checking return value for Save dialog, be sure to check for nsIFilePicker.returnReplace too.
• Available modes: modeOpen, modeSave, modeGetFolder, modeOpenMultiple.
• Available filters: filterAll, filterHTML, filterText, filterImages, filterXML, filterXUL, filterApps.

References

• nsIFilePicker interface.