def inject_condition_expressions()

in boto3/dynamodb/transform.py [0:0]


    def inject_condition_expressions(self, params, model, **kwargs):
        """Injects the condition expression transformation into the parameters

        This injection includes transformations for ConditionExpression shapes
        and KeyExpression shapes. It also handles any placeholder names and
        values that are generated when transforming the condition expressions.
        """
        self._condition_builder.reset()
        generated_names = {}
        generated_values = {}

        # Create and apply the Condition Expression transformation.
        transformation = ConditionExpressionTransformation(
            self._condition_builder,
            placeholder_names=generated_names,
            placeholder_values=generated_values,
            is_key_condition=False
        )
        self._transformer.transform(
            params, model.input_shape, transformation,
            'ConditionExpression')

        # Create and apply the Key Condition Expression transformation.
        transformation = ConditionExpressionTransformation(
            self._condition_builder,
            placeholder_names=generated_names,
            placeholder_values=generated_values,
            is_key_condition=True
        )
        self._transformer.transform(
            params, model.input_shape, transformation,
            'KeyExpression')

        expr_attr_names_input = 'ExpressionAttributeNames'
        expr_attr_values_input = 'ExpressionAttributeValues'

        # Now that all of the condition expression transformation are done,
        # update the placeholder dictionaries in the request.
        if expr_attr_names_input in params:
            params[expr_attr_names_input].update(generated_names)
        else:
            if generated_names:
                params[expr_attr_names_input] = generated_names

        if expr_attr_values_input in params:
            params[expr_attr_values_input].update(generated_values)
        else:
            if generated_values:
                params[expr_attr_values_input] = generated_values