Provide an API to interact with a table schema descriptor - fieldNames, primaryKey etc properties?

[georgeslabreche]

No description provided.

[georgeslabreche]

@pwalsh:

1. Implemented getter for field names.
2. Implemented getter and setter for primary key.
3. Implemented primary key parser when loading schema from file or JSON object.

Test cases here:

tableschema-java/src/test/java/io/frictionlessdata/tableschema/SchemaTest.java

Lines 88 to 118 in 9b9b4ae

	@Test
	public void testCreateSchemaFromFileWithValidPrimaryKey() throws Exception{
	String sourceFileAbsPath = TableTest.class.getResource("/fixtures/simple_schema_with_valid_pk.json").getPath();
	Schema schemaWithValidPK = new Schema(sourceFileAbsPath);
	Assert.assertEquals("id", schemaWithValidPK.getPrimaryKey());
	}
	@Test
	public void testCreateSchemaFromFileWithInvalidPrimaryKey() throws Exception{
	String sourceFileAbsPath = TableTest.class.getResource("/fixtures/simple_schema_with_invalid_pk.json").getPath();
	exception.expect(PrimaryKeyException.class);
	Schema schemaWithInvalidPK = new Schema(sourceFileAbsPath);
	}
	@Test
	public void testCreateSchemaFromFileWithValidCompositeKey() throws Exception{
	String sourceFileAbsPath = TableTest.class.getResource("/fixtures/simple_schema_with_valid_ck.json").getPath();
	Schema schemaWithValidCK = new Schema(sourceFileAbsPath);
	Assert.assertArrayEquals(new String[]{"name", "surname"}, schemaWithValidCK.getPrimaryKey());
	}
	@Test
	public void testCreateSchemaFromFileWithInvalidCompositeKey() throws Exception{
	String sourceFileAbsPath = TableTest.class.getResource("/fixtures/simple_schema_with_invalid_ck.json").getPath();
	exception.expect(PrimaryKeyException.class);
	Schema schemaWithInvalidCK = new Schema(sourceFileAbsPath);
	}

And here:

tableschema-java/src/test/java/io/frictionlessdata/tableschema/SchemaTest.java

Lines 316 to 375 in 9b9b4ae

	@Test
	public void testSinglePrimaryKey() throws PrimaryKeyException{
	Schema schema = new Schema();
	Field idField = new Field("id", Field.FIELD_TYPE_INTEGER);
	schema.addField(idField);
	schema.setPrimaryKey("id");
	String key = schema.getPrimaryKey();
	Assert.assertEquals("id", key);
	}
	@Test
	public void testInvalidSinglePrimaryKey() throws PrimaryKeyException{
	Schema schema = new Schema();
	Field idField = new Field("id", Field.FIELD_TYPE_INTEGER);
	schema.addField(idField);
	exception.expect(PrimaryKeyException.class);
	schema.setPrimaryKey("invalid");
	}
	@Test
	public void testCompositePrimaryKey() throws PrimaryKeyException{
	Schema schema = new Schema();
	Field idField = new Field("id", Field.FIELD_TYPE_INTEGER);
	schema.addField(idField);
	Field nameField = new Field("name", Field.FIELD_TYPE_STRING);
	schema.addField(nameField);
	Field surnameField = new Field("surname", Field.FIELD_TYPE_STRING);
	schema.addField(surnameField);
	schema.setPrimaryKey(new String[]{"name", "surname"});
	String[] compositeKey = schema.getPrimaryKey();
	Assert.assertEquals("name", compositeKey[0]);
	Assert.assertEquals("surname", compositeKey[1]);
	}
	@Test
	public void testInvalidCompositePrimaryKey() throws PrimaryKeyException{
	Schema schema = new Schema();
	Field idField = new Field("id", Field.FIELD_TYPE_INTEGER);
	schema.addField(idField);
	Field nameField = new Field("name", Field.FIELD_TYPE_STRING);
	schema.addField(nameField);
	Field surnameField = new Field("surname", Field.FIELD_TYPE_STRING);
	schema.addField(surnameField);
	exception.expect(PrimaryKeyException.class);
	schema.setPrimaryKey(new String[]{"name", "invalid"});
	}

Foreign Key parsing, getting, and setting has not been implemented. Created Issue #12 for this.