Add structural YAML-validation

[nuest]

This is especially useful when we allow arbitrary content, see https://codecheck.org.uk/spec/config/1.0/#additional-content

Steps

• after saving the CODECHECK metadata form (cf. Feature/codecheck metadata form #59) the YAML file should be internally created once and its contents should be retrieved
• it should then be structurally validated (parsing the file once with Symfony YAML), communicating errors back to the user
• the user only gets to download the file if there are no errors
• write unit tests

[dxL1nus]

Or https://symfony.com/doc/current/components/yaml.html#clear-error-messages ?

This YAML parser here is better for our use case than https://www.php.net/manual/en/function.yaml-parse.php as the Symfony one is a module that can be included and loaded with composer whereas the first one has to somewhat be installed manually. I already use the Symfony YAML parser to retrieve information from loading an existing codecheck.yml file from an exisitng repository. So we should definitely use that one.

It could be that just parsing the file once will already work as a validation.

Shouldn't we also validate if the YAML content has the correct format according to the latest CODECHECK YAML specification like e.g. it is done with the python notebook when creating a codecheck.pdf from the codecheck.yml? So e.g. that the report field actually has a link to some repository and so on?

[dxL1nus]

i am also ready to push this to the holiday iteration, if all other tasks should be done before then @nuest, because this seems to be not to big of a task and it seems to be relatively independent from other tasks

[nuest]

A validation of conformity with the specification is certainly desirable, but let's cover that in a separate issue and at a later stage.

Yes, please go ahead with the Symfony module.

[nuest]

i am also ready to push this to the holiday iteration, if all other tasks should be done before then @nuest, because this seems to be not to big of a task and it seems to be relatively independent from other tasks

Yes, please do.

[dxL1nus]

A validation of conformity with the specification is certainly desirable, but let's cover that in a separate issue and at a later stage.

Yes, please go ahead with the Symfony module.

ok that is of course a good idea to split this into separate issues

[dxL1nus]

When pressing the Save Button the Yaml contents are generated and then structurally validated. If the structure is wrong the save process is terminated and the user gets the corresponding error message as can be seen here:

along with a more detailed error message in the console:

If the validation is successful though, the save process continues as normal and the YAML file can then be downloaded as expected.

[nuest]

along with a more detailed error message in the console:

Do you men the browser console? That is not accessible to the regular user. Can you parse the error message and put it (possibly with a cut off after x characters) into the error message in the browser?

[dxL1nus]

along with a more detailed error message in the console:

Do you men the browser console? That is not accessible to the regular user. Can you parse the error message and put it (possibly with a cut off after x characters) into the error message in the browser?

yes I mean't the browser console but I can of course also show it directly in the UI yes

[dxL1nus]

The concrete validation error message now gets displayed directly below the save button after hitting save, if the YAML structure of the to be created file is invalid.

This is for the example of the following invalid YAML file:

this:
   >is:
       invalid: |
            yaml
            content.