Change language link prefix into a URL template in vlo configuration

[Twan Goosen]

I retrieved the following request from Sander:

...can you change the VLO, where it produces URLs of the form ​http://infra.clarin.eu/service/language/info.php?code={language_code} to make it produce those of the form ​https://infra.clarin.eu/content/language_info/data/{language_code}.html? The old URLs still work, but I'm keen to take them down.

At the moment (VLO 3.1) this can NOT be done because this URL is defined as follows:

<languageLinkPrefix>http://infra.clarin.eu/service/language/info.php?code</languageLinkPrefix>

The web app just appends the language code, so it has to be the last part of the URL.

To make the desired reconfiguration possible, replace this with a new configuration parameter that defines a URL template, i.e. has a placeholder for the language code. This could look like this:

<languageLinkTemplate>https://infra.clarin.eu/content/language_info/data/{}.html</languageLinkTemplate>

(or whatever placeholder syntax makes sense)

[Twan Goosen]

Fixed in r6193