Bug in MetaWizard widget

[pgerundt]

Steps to reproduce:

1. Add a new language
2. Enter data
3. Save

When deleting the recently added language, a JS error is thrown.

Cause: The metaDelete() method in core.js tries to re-enable the language in the select field:

contao/core-bundle/src/Resources/public/core.js

Line 2329 in 6742d9e

opt.getElement('option[value=' + li.getProperty('data-language') + ']').removeProperty('disabled');

But the select field does not contain (disabled) language options of currently used languages.

Maybe the language should not be removed from the select field:

contao/core-bundle/src/Resources/contao/widgets/MetaWizard.php

Line 166 in 6742d9e

unset($languages[$lang]);

But instead the active languages should be added with the "disabled" attribute to the select:

contao/core-bundle/src/Resources/contao/widgets/MetaWizard.php

Line 179 in 6742d9e

$options[] = '<option value="' . $k . '">' . $v . '</option>';

Maybe something like this:
$options[] = '<option value="' . $k . '"' . ($this->varValue[$k] ? ' disabled="disabled"' : '') . '>' . $v . '</option>';
and removing the unset() in L166

[leofeyer]

I cannot reproduce this. Which browser and OS did you test?

[pgerundt]

Really? The issue is totally independent from OS or browser. (I'm using Firefox, Chrome and Safari on MacOS.)
When deleting a language, the core.js tries to remove the "disabled" property from that language select option.
But currently used languages are not added to the select box AFTER SAVING.

Did you really click "save" after adding a new language?

[leofeyer]

Yes, I did. See https://www.dropbox.com/s/symjuc9yoy6v7j0/626.mov?dl=0

[pgerundt]

Clean install of v4.7.7 and the bug still occurs.
We should track it down to either PHP or JS.

Question: After adding a language and saving, does "your" select element contain the recently added language as a disabled option item?

"Mine" doesn't, so the JS error is thrown.

[fritzmg]

Please improve your reproduction steps:

• What Accept-Language is used in your requests?
• How many website roots do you have in which languages?
• Which language was pre-selected in the meta wizard?
• Which language did you add and subsequently delete?

[pgerundt]

I'm sorry, I didn't provide these informations before, because they don't seem to have impact on the bug:

• The Accept-Language is de,en;q=0.7,en-US;q=0.3
• I tested with a single website root in de then switched it to en and finally setup two roots with de and en
• After uploading a file, the languages of the website roots are pre-selected (so de, then en and finally de and en)
• Any language added cannot be deleted after saving

So to sum it up:

• The error occurs in several C4.7.7 installations - even in a clean install. So it's not caused by any extension.
• It doesn't matter how many website roots are present; event their language doesn't have an impact (except for the pre-selection).
• The JS is correct, it tries to re-enable a language in the select field after deletion, but the PHP unset()s currently used languages. So the JS error occurs.
• The error occurs in Firefox, Chrome and Safari on MacOS.

[fritzmg]

@leofeyer I can reproduce the error in Contao 4.7.7 using @pgerundt 's reproduction.

[fritzmg]

Hm, in fact, I cannot delete any language at any point... am I encountering a different error? The JavaScript error is

TypeError: n.getElement(...) is null
mootools.min.js,mooRainbow.min.js,chosen.min.js,simplemodal.min....-c2b8a5e1.js:7:35094

[pgerundt]

Thank you!
Yep, that's the error.
If you take a look at the core.js L2329 and the MetaWizard.php L166 from my first posting, it's pretty clear why you cannot delete any languages:

MetaWizard.php doesn't add active languages to the select and core.js tries to re-enable this non-existing item.

Still wondering why it works @leofeyer ...

[leofeyer]

@fritzmg Can you also reproduce it in the latest 4.8 branch?

[fritzmg]

Yeah, same error still happens in 4.8.x-dev (dac2ccc).

[pgerundt]

Guess, it's been there since
5402a0c#diff-ad0d5d4cc8531e1b48a7c869d477982f

[leofeyer]

Fixed in ecbe36f. @pgerundt Thank you for debugging this one so thoroughly. 👍