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form sending undefined

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  form sending undefined Andrew Poulos <ap_prog@hotmail.com> - 2017-01-17 16:21 +1100
    Re: form sending undefined JJ <jj4public@vfemail.net> - 2017-01-17 15:15 +0700
    Re: form sending undefined "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-01-17 15:29 +0100
    Re: form sending undefined Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-01-17 16:16 +0100
      Re: form sending undefined Andrew Poulos <ap_prog@hotmail.com> - 2017-01-19 12:13 +1100
        Re: form sending undefined Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-01-19 18:19 +0100
          Re: form sending undefined Andrew Poulos <ap_prog@hotmail.com> - 2017-01-20 07:28 +1100

#32188 — form sending undefined

I have a simple form with two input fields (one of type email and the 
other a text area) and when users select Submit I do a simple check to 
make sure that both fields have been filled in. For the email field:

val = h.elements['email'].value.replace(/\s/g,"");

if (val == "") {
   err = "You need to include your email.";
}

And on modern browsers the email field is self validates.

In all the testing I've done on multiple browsers in multiple 
environments it works as expected but about 5% of the emails it 
generates have the value
   undefined
for both inputs.

How do the values become undefined?

Andrew Poulos

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#32189

On Tue, 17 Jan 2017 16:21:46 +1100, Andrew Poulos wrote:
> I have a simple form with two input fields (one of type email and the 
> other a text area) and when users select Submit I do a simple check to 
> make sure that both fields have been filled in. For the email field:
> 
> val = h.elements['email'].value.replace(/\s/g,"");
> 
> if (val == "") {
>    err = "You need to include your email.";
> }
> 
> And on modern browsers the email field is self validates.
> 
> In all the testing I've done on multiple browsers in multiple 
> environments it works as expected but about 5% of the emails it 
> generates have the value
>    undefined
> for both inputs.
> 
> How do the values become undefined?
> 
> Andrew Poulos

Are you sure those are the only relevant code? Cause I'm guessing that other
code is causing it.

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#32190

Andrew Poulos <ap_prog@hotmail.com> wrote on 17 Jan 2017 in 
comp.lang.javascript:

> I have a simple form with two input fields (one of type email and the 
> other a text area) and when users select Submit I do a simple check to 
> make sure that both fields have been filled in. For the email field:
> 
> val = h.elements['email'].value.replace(/\s/g,"");
> 
> if (val == "") {
>    err = "You need to include your email.";
>}
> 
> And on modern browsers the email field is self validates.
> 
> In all the testing I've done on multiple browsers in multiple 
> environments it works as expected but about 5% of the emails it 
> generates have the value
>    undefined
> for both inputs.
> 
> How do the values become undefined?

They could be empty, but not undefined, 
unless you made some mistake in the code not shown.

regex replace() and then compare to ""?
Why not use regex test()?

try [tested]:

<form onsubmit = 'return testForm(this)'>
	<input type='email' name='myEmail'>
	<input type='text' name='myText'>
	<input type='submit'>
</form>

<script type='text/javascript'> 'use strict'
function testForm(t) {
    	var okE = /[^\s]/.test(t.elements['myEmail'].value);
    	var okT = /[^\s]/.test(t.elements['myText'].value);
    	if (!okE) alert("You need to include your email-ADDRESS");
    	if (!okT) alert("You need to give some text");
    	return okE && okT;
};
</script>

-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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#32191

Andrew Poulos wrote:

> I have a simple form with two input fields (one of type email and the
> other a text area) and when users select Submit I do a simple check to
> make sure that both fields have been filled in. For the email field:
> 
> val = h.elements['email'].value.replace(/\s/g,"");

\s+ is more efficient.

> 
> if (val == "") {
>    err = "You need to include your email.";
> }

  if (!/\S/.test(val))

without the assignment before, is more efficient.

If your purpose is to trim leading and trailing whitespace as well, you 
should use

  var err;

  var email = h.elements['email'].value;
  email = (typeof email.trim == "function"
    ? email.trim()
    : email.replace(/^\s+|\s+$/g, ""));

  if (!/\S/.test(email)) {
    err = "You need to include your e-mail address.";
  }

    [The variable identifier should be indicative of the variable value.  
     Also, “e(-)mail” is the name of the technology and the message, not
     of the address.]

See the FAQ.  Or polyfill String.prototype.trim() if necessary and just call 
.trim().

> And on modern browsers the email field is self validates.

Do you mean the “pattern” attribute in HTML5?
 
> In all the testing I've done on multiple browsers in multiple
> environments it works as expected but about 5% of the emails it
> generates have the value
>    undefined
> for both inputs.
> 
> How do the values become undefined?

There is no way that this code can cause the “undefined” value.
The problem must be in the code that you have not posted.

A possibility for an “undefined” value as the result is if you forgot the 
second argument to String.prototype.replace().  It happened to me recently.

-- 
PointedEars
FAQ: <http://PointedEars.de/faq> | <http://PointedEars.de/es-matrix>
<https://github.com/PointedEars> | <http://PointedEars.de/wsvn/>
Twitter: @PointedEars2 | Please do not cc me./Bitte keine Kopien per E-Mail.

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#32192

On 18/01/2017 2:16 AM, Thomas 'PointedEars' Lahn wrote:
> Andrew Poulos wrote:

>> How do the values become undefined?
>
> There is no way that this code can cause the “undefined” value.
> The problem must be in the code that you have not posted.

Looking through everything again one of the fields had an id and name of 
"name" and at a guess that is probably an unsafe name.

Still I found your and Evertjan's code for testing the values very useful.

Andrew Poulos

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#32197

Andrew Poulos wrote:

> On 18/01/2017 2:16 AM, Thomas 'PointedEars' Lahn wrote:
>> Andrew Poulos wrote:
>>> How do the values become undefined?
>> There is no way that this code can cause the “undefined” value.
>> The problem must be in the code that you have not posted.
> 
> Looking through everything again one of the fields had an id and name of
> "name" and at a guess that is probably an unsafe name.

Yes, if you attempt to access the “name” property of the “form” element 
object.  Because legacy DOM support will make that property inaccessible in 
favor to shorthand access to a form control with name or ID “name” in that 
form:

| > $0.name
| <input name=​"name">​

(when will they finally remove support for the ambiguous shorthand and fix 
this?).  The same as naming a form control “submit” will make the “form” 
element object’s submit() method inaccessible:

| > $0.submit
| <input name=​"submit">​
| 
| > $0.submit()
| Uncaught TypeError: $0.submit is not a function(…)

[$0 is an expression referring to to the element object representing the 
node selected in the Element’s panel of several browser developer tools, 
including Chrome DevTools where this was tested.]

However, I do not see an intrinsic relationship between your “undefined” 
result and unsafe naming.

-- 
PointedEars
FAQ: <http://PointedEars.de/faq> | <http://PointedEars.de/es-matrix>
<https://github.com/PointedEars> | <http://PointedEars.de/wsvn/>
Twitter: @PointedEars2 | Please do not cc me./Bitte keine Kopien per E-Mail.

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#32200

On 20/01/2017 4:19 AM, Thomas 'PointedEars' Lahn wrote:
> Andrew Poulos wrote:
>
>> On 18/01/2017 2:16 AM, Thomas 'PointedEars' Lahn wrote:
>>> Andrew Poulos wrote:
>>>> How do the values become undefined?
>>> There is no way that this code can cause the “undefined” value.
>>> The problem must be in the code that you have not posted.
>>
>> Looking through everything again one of the fields had an id and name of
>> "name" and at a guess that is probably an unsafe name.
>
> Yes, if you attempt to access the “name” property of the “form” element
> object.  Because legacy DOM support will make that property inaccessible in
> favor to shorthand access to a form control with name or ID “name” in that
> form:
>
> | > $0.name
> | <input name=​"name">​
>
> (when will they finally remove support for the ambiguous shorthand and fix
> this?).  The same as naming a form control “submit” will make the “form”
> element object’s submit() method inaccessible:
>
> | > $0.submit
> | <input name=​"submit">​
> |
> | > $0.submit()
> | Uncaught TypeError: $0.submit is not a function(…)
>
> [$0 is an expression referring to to the element object representing the
> node selected in the Element’s panel of several browser developer tools,
> including Chrome DevTools where this was tested.]
>
> However, I do not see an intrinsic relationship between your “undefined”
> result and unsafe naming.

In fact last night the client just got another email with undefined so 
it is something else. Dang, I'll keep looking.

Andrew Poulos

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