databinding-lint

The Data Binding Library allows you to bind UI components in your layouts to data sources in your app using a declarative format rather than programmatically. Data Binding is a very powerful library and if you are not careful with it, you will end up writing lots of business logic in your XML files. databinding-lint library provides set of lint checks to detect binding expressions with such logic.

Download

Download the latest artifact from Maven central at following coordinates:

implementation 'com.github.annypatel.databinding:lint-checks:1.0.0-alpha2'

Lint Checks

• CastOperator - Detects cast operation in binding expression.

   res/layout/example.xml:5: Error: Cast operator in binding expression [CastOperator]
      android:text="@{(String) count}" />
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• UnaryOperator - Detects usage of unary operators +, -, ! and ~.

   res/layout/example.xml:5: Error: Unary operator in binding expression [UnaryOperator]
      android:text="@{+count}" />
      ~~~~~~~~~~~~~~~~~~~~~~~~
  

• MathOperator - Detects usage of mathematical operators +, -, *, / and %.

   res/layout/example.xml:5: Error: Mathematical operator in binding expression [MathOperator]
       android:text="@{width * height}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• BitShiftOperator - Detects usage of bit-shift operators <<, >> and >>>.

   res/layout/example.xml:5: Error: Bit-shift operator in binding expression [BitShiftOperator]
       android:text="@{x >> 2}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~
  

• CompareOperator - Detects usage of comparison operators <, <=, >, >=, == and !=.

   res/layout/example.xml:5: Error: Comparison operator in binding expression [CompareOperator]
       android:text="@{length > 0}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• InstanceOfOperator - Detects usage of instanceof operator in binding expression.

   res/layout/example.xml:5: Error: InstanceOf operator in binding expression [InstanceOfOperator]
       android:text="@{data instanceof String}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• BinaryOperator - Detects usage of binary operators &, | and ^.

   res/layout/example.xml:5: Error: Binary operator in binding expression [BinaryOperator]
       android:text="@{a | b}" />
       ~~~~~~~~~~~~~~~~~~~~~~~
  

• AndOrOperator - Detects usage of And-Or operators && and ||.

   res/layout/example.xml:5: Error: AndOr operator in binding expression [AndOrOperator]
       android:text="@{a || b}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~
  

• TernaryOperator - Detects usage of ternary operator in binding expression.

   res/layout/example.xml:5: Error: Ternary operator in binding expression [TernaryOperator]
       android:text="@{a > b ? x : y}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• NullCoalescingOperator - Detects usage of null coalescing ?? operator.

   res/layout/example.xml:5: Error: Null Coalescing operator in binding expression [NullCoalescingOperator]
       android:text="@{data ?? fallback}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• GroupOperator - Detects usage of grouping () in binding expression.

   res/layout/example.xml:5: Error: Group operator in binding expression [GroupOperator]
       android:text="@{(width + height) / 2}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• BracketOperator - Detects usage of bracket operator [] for accessing collections such as list[index] or map[key].

   res/layout/example.xml:5: Error: Bracket operator in binding expression [BracketOperator]
       android:text="@{list[1]}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~
  

• ClassExtractionExpression - Detects .class access in binding expression.

   res/layout/example.xml:5: Error: Class extraction in binding expression [ClassExtractionExpression]
       android:text="@{String.class}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• LiteralExpression - Detects hardcoded java literals in binding expression.

   res/layout/example.xml:5: Error: Literal in binding expression [LiteralExpression]
       android:text="@{\"Data\"}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• MethodCallExpression - Detects method calls in binding expressions.

   res/layout/example.xml:5: Error: Method call in binding expression [MethodCallExpression]
       android:text="@{String.valueOf(count)}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

• GlobalMethodCallExpression - Detects global method calls in binding expressions.

   res/layout/example.xml:5: Error: Global method call in binding expression [GlobalMethodCallExpression]
       android:text="@{valueOf(count)}" />
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~