scalikejdbc.SQLInterpolationMacro.scala Maven / Gradle / Ivy
/*
* Copyright 2013 Kazuhiro Sera
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
package scalikejdbc
import scala.language.experimental.macros
import scala.reflect.macros._
import scalikejdbc.interpolation.SQLSyntax
/**
* Macros for dynamic fields validation
*/
object SQLInterpolationMacro {
def selectDynamic[E: c.WeakTypeTag](c: Context)(name: c.Expr[String]): c.Expr[SQLSyntax] = {
import c.universe._
val nameOpt: Option[String] = try {
Some(c.eval(c.Expr[String](c.resetAllAttrs(name.tree.duplicate))))
} catch {
case t: Throwable => None
}
// primary constructor args of type E
val expectedNames = c.weakTypeOf[E].declarations.collectFirst {
case m: MethodSymbol if m.isPrimaryConstructor => m
}.map { const =>
const.paramss.map { symbols: List[Symbol] => symbols.map(s => s.name.encoded.trim) }.flatten
}.getOrElse(Nil)
nameOpt.map { _name =>
if (!expectedNames.isEmpty && !expectedNames.contains(_name)) {
c.error(c.enclosingPosition, s"${c.weakTypeOf[E]}#${_name} not found. Expected fields are ${expectedNames.mkString("#", ", #", "")}.")
}
}
c.Expr[SQLSyntax](Apply(Select(c.prefix.tree, newTermName("field")), List(name.tree)))
}
}