ICU Message Format

All Tolgee SDKs are following ICU (International Components for Unicode) Message Format. Let's see, how to work with it.

Providing values

The easiest example is how to include external parameters in your message.

Hello, I am {name}.

If your parameter name is John, the output will be Hello, I am John.

Plurals

Sometimes you need to specify the form of some part of the message depending on provided number value.

{dogsCount, plural, one {One dog is} other {# dogs are}} here.

In English this is relatively easy. We need just 2 forms of the word dog and be verb. If we would like to be even cooler, we could provide special form for 0 dogs.

{dogsCount, plural, =0 {No dogs} one {One dog is} other {# dogs are}} here.

If we are translating into other languages, this could be much more complicated. Fortunately, it's simple to cover all the cases. For example in Czech language we will need to cover these cases:

{dogsCount, plural,
  =0 {Žádní psi tu nejsou}
  one {Je tu jeden pes}
  few {Jsou tu # psi}
  other {Je tu # psů}}.

Notice, that you can also use tags like few or many.

All supported tags are:

• =# – used for matching on an exact number (=0, =1, etc.)
• zero
• one – singular
• two – dual
• few – paucal
• many – also used for fractions if they have a separate class
• other – required, general plural form (also used if the language only has a single form)

This will cover all the cases we need. For more information about plural rules, read Unicode's Plural rules documentation.

Selecting value

Sometimes we need to change the form of some part of translation depending on exact value match. One of these cases is selecting proper form by gender. Again, this is something you will need in Czech language.

{gender, select, male {Uživatel uložil} female {Uživatelka uložila} other {Uživatel uložil}} soubor.

Combining the rules

Sometimes, you would like to combine the rules. This is no problem, you can provide messages like this:

{gender_of_host, select,
  female {
    {num_guests, plural, offset:1
      =0 {{host} does not give a party.}
      =1 {{host} invites {guest} to her party.}
      =2 {{host} invites {guest} and one other person to her party.}
      other {{host} invites {guest} and # other people to her party.}}}
  male {
    {num_guests, plural, offset:1
      =0 {{host} does not give a party.}
      =1 {{host} invites {guest} to his party.}
      =2 {{host} invites {guest} and one other person to his party.}
      other {{host} invites {guest} and # other people to his party.}}}
  other {
    {num_guests, plural, offset:1
      =0 {{host} does not give a party.}
      =1 {{host} invites {guest} to their party.}
      =2 {{host} invites {guest} and one other person to their party.}
      other {{host} invites {guest} and # other people to their party.}}}}

To read more about ICU format, you can follow the ICU User Guide.

Source: userguide.icu-project.org.