ConfigFile as API

The ConfigFile as API is a formal Treble interface describing schemas of
configuration files used across system and vendor partitions.
The Java APIs in the current.txt file are not Java APIs for apps. It's a proxy
for the schema of a xml file used between the system and vendor partition.
The xml files are only ever parsed by apps on the system partition.

Add Schema

Add the schema (attribute, element or new complexType …) you want to add to the
xsd file.

before

<xs:element name="class">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="student" type="xs:string"/>
    </xs:sequence>
    <xs:attribute name="name" type=”xs:string”/>
  </xs:complexType>
</xs:element>

after

<xs:element name="class">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="student" type="xs:string"/>
    </xs:sequence>
    <xs:attribute name="name" type=”xs:string”/>
    <xs:attribute name="number" type="xs:int"/>
  </xs:complexType>
</xs:element>

Then run "make {xsd_config module_name} .docs-update-current-api" or "make
update-api" to update all the xsd_config modules.

In the above example, two functions are added as below.
* method public int getNumber();
* method public void setNumber(int);

Remove Schema

To remove a tag, add an annotation tag with the name of "Deprecated" into the
tag to be deleted. Partners are not allowed to create new vendor images using
deprecated tags

before

<xs:element name="class">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="student" type="xs:string"/>
    </xs:sequence>
    <xs:attribute name="name" type=”xs:string”/>
  </xs:complexType>
</xs:element>

after

<xs:element name="class">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="student" type="xs:string">
        <annotation name=”Deprecated”/>
      </xs:element>
    </xs:sequence>
    <xs:attribute name="name" type=”xs:string”/>
  </xs:complexType>
</xs:element>

After adding “Deprecated” annotation, we need to update the api or schema just
like when adding a tag. In the above example, a @Deprecate annotation is added.
* method @Deprecated public java.util.List<java.lang.String> getStudent();
After 2 years we can delete the tag. When deleting, delete the tag in the xsd
file and the api in last_current.txt, and update it.

Release Schema

If there are any changes, we update last_current.txt and last_removed.txt before
release by copying current.txt and removed.txt to last_current.txt and
last_removed.txt.

Supported/Unsupported Tags

Only the follow tags and attributes are allowed:

Supported

"xsd:schema" [
]

"xsd:element" [
    "xsd:name" {
        values: any valid java name
    }
    "xsd:type" {
        values: built-in data type, simpleType or complexType
    },
    "xsd:ref" {
        values: another element
    },
    "xsd:minOccurs" {
        values: [ 0, maxOccurs ]
    },
    "xsd:maxOccurs" {
        values: [ 1, unbounded ]
    },
]

"xsd:attribute" [
    "xsd:name" {
        values: any valid java name
    }
    "xsd:type" {
        values: built-in data type, simpleType or complexType
    },
    "xsd:ref" {
        values: another element
    },
]

"xsd:complexType" [
    "xsd:name" {
        values: any valid java name
    }
]

"xsd:complexContent" [
]

"xsd:simpleContent" [
]

"xsd:restriction": [
    "xsd:base" {
        values: built-in data type
    }
]

"xsd:extension": [
    "xsd:base" {
        values: built-in data type, simpleType or complexType
    }
]

"xsd:simpleType": [
    "xsd:name" {
        values: any valid java name
    }
]

"xsd:list": [
    "xsd:itemType" {
        values: built-in data type, or simpleType
    }
]

"xsd:union": [
    "xsd:memberTypes" {
        values: built-in data type, or simpleType
    }
]

"xsd:sequence": [
]

"xsd:choice": [
]

"xsd:all": [
]

"xsd:enumeration": [
    "xsd:value" {
        values: built-in data type
    }
]