The structure of XLIFF files and Strings files, used to localize iOS apps, is not the same. For this reason, setting up a translation project is a little different too when you're localizing Apple software with POEditor, using one file or the other.
Setting up the localization project
The first steps are the same for both .strings localization and .xliff localization: create a project in your account and add a language to it.
Then, click on the Import in the project page to add terms. Choose the file you want to translate and then select the option Also import translations to... and pick the language you've previously added.
At this point things get a little different.
Because .strings files consist of one or more key-value pairs, while XLIFF files can contain, beside the string IDs, both the strings from the source language and those from the translated language.
When working with XLIFF files, you will have to choose whether to import translations from the <source>
tag or from the <target>
tag.
Translating the software strings
After importing the terms and the translations to a language, go to the localization project's Settings and set that language as Default Referece Language. It will be displayed instead of the labels, across the whole project, for all the project members to see.
Then, in the project page, add the languages in which you want the software to be localized and add contributors to them, to translate the strings.
Exporting the localized strings
To download translations for a language, press the Export button in the Language page. While it is recommended to set a Default Reference Language for both .strings and XLIFF-based localization projects, for XLIFF you must have a Default Reference Language set on the project, so it can be placed in the <source>
tag.