TYPO3 Core

I can confirm this issue too...

My TYPO3 9.5.1, PHP 7.2

page {
    meta {
        author = {$page.meta.author}
        author {
             override.field = author
        }
        keywords = {$page.meta.keywords}
        keywords {
             override.field = keywords
        }
    }
}

...and it is not working

page {
    meta {
        author.data = author
        keywords.data = keywords
    }
}
page {
    meta {
        author.data = levelfield:-1, author, slide
        keywords.data = levelfield:-1, keywords, slide
    }
}

...very strange but it is working

page {
    meta {
        description = {$page.meta.description}
        description {
             override.field = description
        }
    }
}

...and it is working

page {
    meta {
        keywords.data = page:keywords
        author.data = page:author
    }
}

Tested on the TYPO3 v. 9.5.1 with Bootstrap Package 10.0.4 - working

page {
    meta {
        keywords = {$page.meta.keywords}
        keywords {
            stdWrap {
                override {
                    data = page:keywords
                }
            }
        }
        author = {$page.meta.author}
        author {
            stdWrap {
                override {
                    data = page:author
                }
            }
        }
    }
}

These are my findings with TYPO3 9.5.2 (latest master)
- I created three constants
- on one page, I set the values of the fields author, keyword, description

These three lines are always present on each test¶

page.meta.author = {$page.meta.author} >>> constant is shown
page.meta.keywords = {$page.meta.keywords} >>> constant is shown
page.meta.description = {$page.meta.description} >>> Note: in this situation the description field of the page properties will be taken; if not empty!

For each test, I added the following three lines (each time a different set of lines)

Test 1 - added:¶

page.meta.author.override.field = author >>> Does not work; the constant is shown
page.meta.keywords.override.field = keywords >>> Does not work; the constant is shown
page.meta.description.override.field = description >>>Works the field value is taken; but see the previous Note!

Test 2 - added:¶

@page.meta.author.data = author >>> Does not work; the tag is missing
@page.meta.keywords.data = keywords >>> Does not work; the tag is missing
@page.meta.description.data = description >>> Works, but see the previous Note!

Test 4 - added:¶

page.meta.author.data = page:author >>> Works the field value is taken; the tag is missing if empty
page.meta.keywords.data = page:keywords >>> Works the field value is taken; the tag is missing if empty
page.meta.description.data = page:description >>> Works the field value is taken; the tag is missing if empty

Test 5 - added:¶

page.meta.author.data = levelfield:-1, author, slide >>> Works the field value is taken; also the slide works
page.meta.keywords.data = levelfield:-1, keywords, slide >>> Works the field value is taken; also the slide works
page.meta.description.data = levelfield:-1, description, slide >>> Works the field value is taken; also the slide works

NOTE 2: in Install Tool, set ['FE']['addRootLineFields'] => 'author,description,keywords'

Test 6 - added:¶

page.meta.author.override.data = page:author >>> Works the field value is taken; constant is shown if empty
page.meta.keywords.override.data = page:keywords >>> Works the field value is taken; constant is shown if empty
page.meta.description.override.data = page:description >>> Works the field value is taken; constant is shown if empty

Test 7 - added:¶

page.meta.author.stdWrap.override.data = page:author >>> Works the field value is taken; constant is shown if empty
page.meta.keywords.stdWrap.override.data = page:keywords >>> Works the field value is taken; constant is shown if empty
page.meta.description.stdWrap.override.data = page:description >>> Works the field value is taken; constant is shown if empty

@Richard Haeser I repeated the same tests with 9.5.4 and had slightly different results:

Test 1 -> same results
Test 2 -> one different result:
page.meta.description.data = description >>> Value from field is taken if not empty; Tag is missing if empty
Test 4 -> same results
Test 5 -> all different results:
page.meta.author.data = levelfield:-1, author, slide >>> Does not work; the tag is missing; also the slide works
page.meta.keywords.data = levelfield:-1, keywords, slide >>> Does not work; the tag is missing; also the slide works
page.meta.description.data = levelfield:-1, description, slide >>> Value from field is taken if not empty; Tag is missing if empty; also the slide works
Test 6 -> same results
Test 7 -> same results

I cleared the frontend cache before each test.

This issue still seems active in 9.5.5

As a workaround we solved it like this:

1. Deactivate rendering of the seo tags:
$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['TYPO3\CMS\Frontend\Page\PageGenerator']['generateMetaTags'] = NULL;

2. Set the fields to slide=true:
$GLOBALS['TYPO3_CONF_VARS']['FE']['addRootLineFields'] = 'og_title,og_description,og_image,twitter_title,twitter_description,twitter_image,author,author_email';

3. Manually manage seo tags using TS:

70 = COA
        70 {
    # OG:TITLE ###########################################
            10 = TEXT
            10 {
                data = levelfield:-1, og_title, slide
                noTrimWrap = |<meta property="og:title" content="|" />|
            }
    # OG:TYPE ###########################################
            20 = TEXT
            20 {
                value = website
                noTrimWrap = |<meta property="og:type" content="|" />|
            }
    # OG:URL #############################################
            30 = TEXT
            30 {
                typolink {
                    parameter.data = tsfe:id
                    parameter.insertData = 1
                    useCacheHash = 1
                    addQueryString = 1
                    addQueryString.method = get
                    addQueryString.exclude = id
                    forceAbsoluteUrl = 1
                    returnLast = url
                }
                wrap = <meta property="og:url" content="|">
            }
    # OG:DESCRIPTION ######################################
            40 = TEXT
            40 {
                data = levelfield:-1, og_description, slide
                stdWrap.wrap = <meta property="og:description" content="|" />
            }
    # OG:IMAGE ############################################
    # Adaption for news see below
            50 = FILES
            50 {
                references {
                    data = levelfield:-1, og_image, slide
                }
                renderObj = IMG_RESOURCE
                renderObj {
                    file.import.data = file:current:publicUrl
                }
                stdWrap.dataWrap =  <meta property="og:image" content="{site:base}|" />
                required = 1
            }
        }

TBD: Check, if these tags are set correctly for news detail pages.

Don't know if there is a better solution?

I repeated my tests (see comment 4) on 9.5.8 with a more rich scenario:

- I created three constants:

page.meta.author = AUTORE DA COSTANTE
page.meta.keywords = KEYWORD DA COSTANTE
page.meta.description = DESCRIPTION DA COSTANTE

- I created four pages

Page A
Author field: filled with AUTORE DA PAGINA
Keyword field: filled with KEYWORD DA PAGINA
Description field: filled with DESCRIPTION DA PAGINA

Page B
Author field: empty
Keyword field: empty
Description field: filled with DESCRIPTION DA PAGINA

Page C
Author field: filled with AUTORE DA PAGINA
Keyword field: filled with KEYWORD DA PAGINA
Description field: empty

Page D
Author field: empty
Keyword field: empty
Description field: empty

So to sum up

Note: for test 5 that involves the "slide" I created a subpage for each page; the fields on all the subpages are always empty;

on Install Tool I set ['FE']['addRootLineFields'] => 'author,description,keywords'

- for each test, the lines:

page.meta.author = {$page.meta.author} 
page.meta.keywords = {$page.meta.keywords} 
page.meta.description = {$page.meta.description}

are always present

- before each test, I cleared the cache

I sum up in the following table the results of all the tests;

legend:

for each cell of the table, I report the values taken for Author, Keywords and Description in this order;

"C" means that the value from the constants is taken; "P" means that the value from the page field is taken; "/" means that the tag is absent

page.meta.author = {$page.meta.author} 
page.meta.keywords = {$page.meta.keywords} 
page.meta.description = {$page.meta.description}

page.meta.author.override.field = author 
page.meta.keywords.override.field = keywords
page.meta.description.override.field = description

page.meta.author.data = author
page.meta.keywords.data = keywords
page.meta.description.data = description

page.meta.author.data = page:author 
page.meta.keywords.data = page:keywords 
page.meta.description.data = page:description

page.meta.author.data = levelfield:-1, author, slide 
page.meta.keywords.data = levelfield:-1, keywords, slide
page.meta.description.data = levelfield:-1, description, slide 

page.meta.author.override.data = page:author 
page.meta.keywords.override.data = page:keywords
page.meta.description.override.data = page:description 

page.meta.author.stdWrap.override.data = page:author 
page.meta.keywords.stdWrap.override.data = page:keywords 
page.meta.description.stdWrap.override.data = page:description 

From a first glance, the test with

page.meta.author.data = author
page.meta.keywords.data = keywords
page.meta.description.data = description

seems to present the most faulty behavior;

Hello Benni, I report here again the results for each test for clarity, discarding the one with incorrect syntax:

1) This one still looks faulty , the value of description from the page is always taken even if I have just defined the constants.
Why only description behaves like that? Is it correct?

page.meta.author = {$page.meta.author} 
page.meta.keywords = {$page.meta.keywords} 
page.meta.description = {$page.meta.description}

2) These ones look correct: the override with the values from page is always done when present - and they're totally equivalent

page.meta.author.override.field = author 
page.meta.keywords.override.field = keywords
page.meta.description.override.field = description

page.meta.author.override.data = page:author 
page.meta.keywords.override.data = page:keywords
page.meta.description.override.data = page:description 

page.meta.author.stdWrap.override.data = page:author 
page.meta.keywords.stdWrap.override.data = page:keywords 
page.meta.description.stdWrap.override.data = page:description 

page.meta.author.data = page:author 
page.meta.keywords.data = page:keywords 
page.meta.description.data = page:description

4) Last but not the least, this looks good, too, it is the same as the previous one, plus the "slide" is correctly considered

page.meta.author.data = levelfield:-1, author, slide 
page.meta.keywords.data = levelfield:-1, keywords, slide
page.meta.description.data = levelfield:-1, description, slide 

Perfect, Riccardo!

With your information I spotted the issue, which resides in the EXT:seo MetaTagGenerator where the "description" field is always taken from the page.

page.meta.description.replace = 1

worked for me

For the description field it is right you need the .replace parameter. So this is expected behaviour. If you want to override the settings with TypoScript you have to use that parameter.

If I'm right we can close this issue.

@Thomas Stranz, @Richard Haeser

I am trying unluckily without success to find where in the documentation it is stated that page.description is a special case that needs the replace function; (looking at https://docs.typo3.org/m/typo3/reference-typoscript/master/en-us/Setup/Page/Index.html?highlight=meta#meta. Is there some other place where to search?)

Riccardo, on the link you have given, in the description of meta you find:

replace If set to 1, the tag will replace the one set earlier by a plugin. If set to 0 (default), the meta tag generated by the plugin will be used. If there is none yet, the one from TypoScript is set.

If that is not sufficient, maybe we have to update the documentation a little bit

@Richard Haeser

Aw... it is embarrassing I haven't seen it :O

If that is not sufficient, maybe we have to update the documentation a little bit

I would suggest to add at least an example to make it more evident, and thanks again for finding it.