Difference between permissions in app manifest

Question

What are the distinct consequences of setting readwrite or readcreate as values of access property for permissions entry in the manifest of a Firefox OS app?

Answer 1

Those permission access values in the manifest are used currently by two APIs, Contacts and Device Storage. For example if your app needs to only read the phone contacts, you have to set "readonly" access. If you set "readwrite" for no good reason (your app doesn't need this higher level of access), your app might fail the review for being added in a marketplace. Another example is if your app just needs to export a contact and save it to the phone contact list. In this case you need to set "createonly". With this setting in your manifest, trying to read or modify an existing phone contact will fail. "readwrite" will allow you to both read, modify and create contacts. "readcreate" will allow you to just read and create contacts.

With those permissions set, the user will be prompted if he wants to allow the corresponding operation. The access levels methods are fine-gained so that the user has more control over what the application can do with his contacts/files.