Error With "null" Field In Email Notification Script - google-app-maker

Question

I apologize. I am sure this is a rookie question, with a simple answer.
So I am using the following to send an email notification when a user creates an entry. Everything works fine, except two behaviors related to "null" (blank) entries.
function newSalesEmailMessage(sendButton) {
var pageWidgets = sendButton.root.descendants;
var fullName = app.datasources.CurrentUser.item.FullName;
var htmlbody = '<b><font size="3">' + fullName + '</font></b>' + ' has created a new sales entry for: ' +
'<h1><span style="color:#2196F3">' + pageWidgets.ShowName.value + '</h1>' +
'<p>Shoot Date: <b>' + pageWidgets.ProjectDate.value.toDateString() + '</b>' +
'<p>Contact: <b>' + pageWidgets.Contact.value + '</b>' +
'<p>Post AP: <b>' + pageWidgets.PostAP.value + '</b>' +
'<p>Sales Person: <b>' + pageWidgets.SalesPerson.value + '</b>' +
'<p>Notes: <b>' + pageWidgets.Notes.value + '</b>';
google.script.run
.withSuccessHandler(function() {
})
.withFailureHandler(function(err) {
console.error(JSON.stringify(err));
})
.sendEmailCreate(
'test#test.com',
'New Sales Entry for: ' + pageWidgets.ShowName.value,
htmlbody);
return sendButton === "" || sendButton === null || sendButton === undefined;
}
Issue 1: Whenever a user leaves a field blank the email puts "null" in the field, which makes sense, but people keep asking me "Who is null?" Ugh.
So if there is a way to output a blank space (ex:"") instead of "null" that would be great.
Issue 2: Whenever a user leaves the ProjectDate (which is a date field) blank I get the error: Cannot read property 'toDateString' of null.
This makes sense, but obviously this causes this script to not complete. I was hoping something like this would fix both issues, but it didn't:
function newSalesEmailMessage(sendButton) {
var pageWidgets = sendButton.root.descendants;
if (pageWidgets === null) {
pageWidgets = "";
}
var fullName = app.datasources.CurrentUser.item.FullName;
var htmlbody = '<b><font size="3">' + fullName + '</font></b>' + ' has created a new sales entry for: ' +
'<h1><span style="color:#2196F3">' + pageWidgets.ShowName.value + '</h1>' +
'<p>Shoot Date: <b>' + pageWidgets.ProjectDate.value.toDateString() + '</b>' +
'<p>Contact: <b>' + pageWidgets.Contact.value + '</b>' +
'<p>Post AP: <b>' + pageWidgets.PostAP.value + '</b>' +
'<p>Sales Person: <b>' + pageWidgets.SalesPerson.value + '</b>' +
'<p>Notes: <b>' + pageWidgets.Notes.value + '</b>';
google.script.run
.withSuccessHandler(function() {
})
.withFailureHandler(function(err) {
console.error(JSON.stringify(err));
})
.sendEmailCreate(
'test#test.com',
'New Sales Entry for: ' + pageWidgets.ShowName.value,
htmlbody);
}
Thank you for your help.

Answer 1

There are multiple ways to handle such situations, the easiest one will be introducing some helper functions:
// This function will return empty string in case widget's value is null
// You can return any default value or even pass it as function's parameter
function getSafeString(widget) {
return widget.value === null ?
'' :
widget.value;
}
function getSafeDate(widget) {
return widget.value === null ?
'' :
widget.value.toDateString();
}
function newSalesEmailMessage(sendButton) {
...
'...some HTML...' + getSafeString(widgets.SomeWidget) + '...some HTML...' +
'...some HTML...' + getSafeDate(widgets.DateWidget) + '...some HTML...'
...
}
By the way, I would also suggest using datasource.item (or datasource.modes.create.item, depending on your bindings), to get user inputs.