Fix html tag support, and update tinymce to v4.40

[bright-pan]

No description provided.

[nfletton]

Just looking at a problem relating to language codes and I think it might be best not to set a default language code here at all but instead leave TinyMCE to provide the default value. With the current code, if you have Django's LANGUAGE_CODE setting is set to a value that does not have a corresponding TinyMCE translation file (https://www.tinymce.com/docs/configure/localization/#language), then the editor will fail to display. For example if the LANGUAGE_CODE is 'en-us' a 404 will occur when TinyMCE tries to load wagtailtinymce/js/vendor/tinymce/langs/en_US.js.

By deferring to TinyMCE's default language at least everyone gets the editor displayed out of the box.

[bright-pan]

Hi, @nfletton

the django localization is not Compatible to the tinymce localization,
for example in django shell,

from django.utils import translation
translation.check_for_language('en')
True
translation.check_for_language('en_US')
False

so, there are two solutions for it`s problem,
the first one, fix it in initialization in TinyMCERichTextArea.
the second one, fix filename for js file name, but it ugly.

i will fix it soon.

[riceyrice]

Thanks for this both, I will take a look this week!

[vintage]

Can't wait for the tinymce 4.4 as it seems to solve the issue with initializing it under FF - tinymce/tinymce#2671

[dperetti]

Please...

[maxpeterson]

The recommended method for updating the whitelisted is to use a construct-whitelister-element-rules hook - this would remove the need for the DbWhitelister subclass

@hooks.register('construct_whitelister_element_rules')
def whitelister_element_rules():
    common = {
        'style': True,
        'width': True,
        'margin-left': True,
        'margin-right': True,
        'height': True,
        'border-color': True,
        'text-align': True,
        'background-color': True,
        'vertical-align': True,
        'font-family': True,
        'valign': True,
    }
    table_rule = attribute_rule(dict(common, **{
        'border': True,
        'cellpadding': True,
        'cellspacing': True,
    }))
    row_rule = attribute_rule(common)
    cell_rule = attribute_rule(dict(common, **{
        'colspan': True,
        'scope': True,
        'rowspan': True,
    }))

    return {
        'blockquote': allow_without_attributes,
        'pre': allow_without_attributes,
        'span': allow_without_attributes,
        'code': allow_without_attributes,

        'table': table_rule,
        'thead': allow_without_attributes,
        'tfoot': allow_without_attributes,
        'tbody': allow_without_attributes,
        'colgroup': allow_without_attributes,
        'col': allow_without_attributes,
        'caption': allow_without_attributes,
        'tr': row_rule,
        'th': cell_rule,
        'td': cell_rule,
    }

[maxpeterson]

Added #15

[bright-pan]

ok，i closed the PR.