net.liftweb.record.Field.scala Maven / Gradle / Ivy
/*
* Copyright 2007-2011 WorldWide Conferencing, LLC
*
* 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 net.liftweb
package record
import net.liftweb.common._
import net.liftweb.http.js.{JsExp}
import net.liftweb.json.JsonAST.{JNothing, JNull, JString, JValue}
import net.liftweb.util._
import scala.reflect.Manifest
import scala.xml._
/** Base trait of record fields, with functionality common to any type of field owned by any type of record */
trait BaseField extends FieldIdentifier with util.BaseField {
private[record] var fieldName: String = _
private[record] var dirty = false
protected def dirty_?(b: Boolean) = dirty = b
def resetDirty {
if (safe_?) dirty_?(false)
}
def dirty_? : Boolean = dirty
/**
* Should the field be ignored by the OR Mapper?
*/
def ignoreField_? = false
/**
* Is the value of this field optional (e.g. NULLable)?
*/
def optional_? = false
/**
* The text name of this field
*/
def name: String = fieldName
/**
* Can the value of this field be read without obscuring the result?
*/
def canRead_? : Boolean = safe_? || checkCanRead_?
/**
* If the owner is not in "safe" mode, check the current environment to see if
* the field can be read
*/
def checkCanRead_? = true
/**
* Can the value of this field be written?
*/
def canWrite_? : Boolean = safe_? || checkCanWrite_?
/**
* If the owner is not in "safe" mode, check the current environment to see if
* the field can be written
*/
def checkCanWrite_? = true
/**
* Convert the field value to an XHTML representation
*/
def toXHtml: NodeSeq = Text(toString)
/**
* Generate a form control for the field
*/
def toForm: Box[NodeSeq]
/**
* Returns the field's value as a valid JavaScript expression
*/
def asJs: JsExp
/** Encode the field value into a JValue */
def asJValue: JValue
/**
* Set the name of this field
*/
private[record] final def setName_!(newName : String) : String = {
if (safe_?) fieldName = newName
fieldName
}
/**
* The error message used when the field value could not be set
*/
def noValueErrorMessage : String = "Value cannot be changed"
/**
* The error message used when the field value must be set
*/
def notOptionalErrorMessage : String = "Value required"
def tabIndex: Int = 1
override def uniqueFieldId: Box[String] = Full(name+"_id")
def label: NodeSeq = uniqueFieldId match {
case Full(id) =>
case _ => NodeSeq.Empty
}
def asString: String
def safe_? : Boolean = true // let owned fields make it unsafe some times
}
/** Refined trait for fields owned by a particular record type */
trait OwnedField[OwnerType <: Record[OwnerType]] extends BaseField {
/**
* Return the owner of this field
*/
def owner: OwnerType
/**
* Are we in "safe" mode (i.e., the value of the field can be read or written without any security checks.)
*/
override final def safe_? : Boolean = owner.safe_?
}
/** Refined trait for fields holding a particular value type */
trait TypedField[ThisType] extends BaseField {
type MyType = ThisType // For backwards compatability
type ValidationFunction = ValueType => List[FieldError]
private[record] var data: Box[MyType] = Empty
private[record] var needsDefault: Boolean = true
/**
* Helper for implementing asJValue for a conversion to an encoded JString
*
* @param encode function to transform the field value into a String
*/
protected def asJString(encode: MyType => String): JValue =
valueBox.map(v => JString(encode(v))) openOr (JNothing: JValue)
/** Decode the JValue and set the field to the decoded value. Returns Empty or Failure if the value could not be set */
def setFromJValue(jvalue: JValue): Box[MyType]
/**
* Helper for implementing setFromJValue for a conversion from an encoded JString
*
* @param decode function to try and transform a String into a field value
*/
protected def setFromJString(jvalue: JValue)(decode: String => Box[MyType]): Box[MyType] = jvalue match {
case JNothing|JNull if optional_? => setBox(Empty)
case JString(s) => setBox(decode(s))
case other => setBox(FieldHelpers.expectedA("JString", other))
}
def validations: List[ValidationFunction] = Nil
/** Validate this field's setting, returning any errors found */
def validate: List[FieldError] = runValidation(valueBox)
/** Helper function that does validation of a value by using the validators specified for the field */
protected def runValidation(in: Box[MyType]): List[FieldError] = in match {
case Full(_) => validations.flatMap(_(toValueType(in))).distinct
case Empty => Nil
case Failure(msg, _, _) => Text(msg)
}
protected implicit def boxNodeToFieldError(in: Box[Node]): List[FieldError] =
in match {
case Full(node) => List(FieldError(this, node))
case _ => Nil
}
protected implicit def nodeToFieldError(node: Node): List[FieldError] =
List(FieldError(this, node))
protected implicit def boxNodeFuncToFieldError(in: Box[MyType] => Box[Node]):
Box[MyType] => List[FieldError] =
param => boxNodeToFieldError(in(param))
/** The default value of the field when no value is set. Must return a Full Box unless optional_? is true */
def defaultValueBox: Box[MyType]
/**
* Convert the field to a String... usually of the form "displayName=value"
*/
def asString = displayName + "=" + data
def obscure(in: MyType): Box[MyType] = Failure("value obscured")
def setBox(in: Box[MyType]): Box[MyType] = synchronized {
needsDefault = false
data = in match {
case _ if !checkCanWrite_? => Failure(noValueErrorMessage)
case Full(_) => set_!(in)
case _ if optional_? => set_!(in)
case (f: Failure) => set_!(f) // preserve failures set in
case _ => Failure(notOptionalErrorMessage)
}
dirty_?(true)
data
}
// Helper methods for things to easily use mixins and so on that use ValueType instead of Box[MyType], regardless of the optional-ness of the field
protected def toValueType(in: Box[MyType]): ValueType
protected def toBoxMyType(in: ValueType): Box[MyType]
protected def set_!(in: Box[MyType]): Box[MyType] = runFilters(in, setFilterBox)
def setFilter: List[ValueType => ValueType] = Nil
/** OptionalTypedField and MandatoryTypedField implement this to do the appropriate lifting of Box[MyType] to ValueType */
protected def liftSetFilterToBox(in: Box[MyType]): Box[MyType]
/**
* A list of functions that transform the value before it is set. The transformations
* are also applied before the value is used in a query. Typical applications
* of this are trimming and/or toLowerCase-ing strings
*/
protected def setFilterBox: List[Box[MyType] => Box[MyType]] = liftSetFilterToBox _ :: Nil
def runFilters(in: Box[MyType], filter: List[Box[MyType] => Box[MyType]]): Box[MyType] = filter match {
case Nil => in
case x :: xs => runFilters(x(in), xs)
}
/**
* Set the value of the field from anything.
* Implementations of this method should accept at least the following (pattern => valueBox)
* - value: MyType => setBox(Full(value))
* - Some(value: MyType) => setBox(Full(value))
* - Full(value: MyType) => setBox(Full(value))
* - (value: MyType)::_ => setBox(Full(value))
* - s: String => setFromString(s)
* - Some(s: String) => setFromString(s)
* - Full(s: String) => setFromString(s)
* - null|None|Empty => setBox(defaultValueBox)
* - f: Failure => setBox(f)
* And usually convert the input to a string and uses setFromString as a last resort.
*
* Note that setFromAny should _always_ call setBox, even if the conversion fails. This is so that validation
* properly notes the error.
*
* The method genericSetFromAny implements this guideline.
*/
def setFromAny(in: Any): Box[MyType]
/** Generic implementation of setFromAny that implements exactly what the doc for setFromAny specifies, using a Manifest to check types */
protected final def genericSetFromAny(in: Any)(implicit m: Manifest[MyType]): Box[MyType] = in match {
case value if m.erasure.isInstance(value) => setBox(Full(value.asInstanceOf[MyType]))
case Some(value) if m.erasure.isInstance(value) => setBox(Full(value.asInstanceOf[MyType]))
case Full(value) if m.erasure.isInstance(value) => setBox(Full(value.asInstanceOf[MyType]))
case (value)::_ if m.erasure.isInstance(value) => setBox(Full(value.asInstanceOf[MyType]))
case (value: String) => setFromString(value)
case Some(value: String) => setFromString(value)
case Full(value: String) => setFromString(value)
case (value: String)::_ => setFromString(value)
case null|None|Empty => setBox(defaultValueBox)
case (failure: Failure) => setBox(failure)
case Some(other) => setFromString(String.valueOf(other))
case Full(other) => setFromString(String.valueOf(other))
case other => setFromString(String.valueOf(other))
}
/**
* Set the value of the field using some kind of type-specific conversion from a String.
* By convention, if the field is optional_?, then the empty string should be treated as no-value (Empty).
* Note that setFromString should _always_ call setBox, even if the conversion fails. This is so that validation
* properly notes the error.
*
* @return Full(convertedValue) if the conversion succeeds (the field value will be set by side-effect)
* Empty or Failure if the conversion does not succeed
*/
def setFromString(s: String): Box[MyType]
def valueBox: Box[MyType] = synchronized {
if (needsDefault) {
needsDefault = false
data = defaultValueBox
}
if (canRead_?) data
else data.flatMap(obscure)
}
/** Clear the value of this field */
def clear: Unit = optional_? match {
case true => setBox(Empty)
case false => setBox(defaultValueBox)
}
}
trait MandatoryTypedField[ThisType] extends TypedField[ThisType] with Product1[ThisType] {
type ValueType = ThisType // For util.BaseField
//TODO: fullfil the contract of Product1[ThisType]
def canEqual(a:Any) = false
def _1 = value
override def optional_? = false
/**
* Set the value of the field to the given value.
* Note: Because setting a field can fail (return non-Full), this method will
* return defaultValue if the field could not be set.
*/
def set(in: MyType): MyType = setBox(Full(in)) openOr defaultValue
def toValueType(in: Box[MyType]) = in openOr defaultValue
def toBoxMyType(in: ValueType) = Full(in)
def value: MyType = valueBox openOr defaultValue
def get: MyType = value
def is: MyType = value
protected def liftSetFilterToBox(in: Box[MyType]): Box[MyType] = in.map(v => setFilter.foldLeft(v)((prev, f) => f(prev)))
/**
* The default value of the field when a field has no value set and is optional, or a method that must return a value (e.g. value) is used
*/
def defaultValue: MyType
def defaultValueBox: Box[MyType] = if (optional_?) Empty else Full(defaultValue)
override def toString = valueBox match {
case Full(null)|null => "null"
case Full(v) => v.toString
case _ => defaultValueBox.map(v => if (v != null) v.toString else "null") openOr ""
}
}
trait OptionalTypedField[ThisType] extends TypedField[ThisType] with Product1[Box[ThisType]] {
type ValueType = Option[ThisType] // For util.BaseField
//TODO: fullfil the contract of Product1[ThisType]
def canEqual(a:Any) = false
def _1 = value
final override def optional_? = true
/**
* Set the value of the field to the given value.
* Note: Because setting a field can fail (return non-Full), this method will
* return defaultValueBox if the field could not be set.
*/
def set(in: Option[MyType]): Option[MyType] = setBox(in) or defaultValueBox
def toValueType(in: Box[MyType]) = in
def toBoxMyType(in: ValueType) = in
def value: Option[MyType] = valueBox
def get: Option[MyType] = value
def is: Option[MyType] = value
protected def liftSetFilterToBox(in: Box[MyType]): Box[MyType] = setFilter.foldLeft(in)((prev, f) => f(prev))
def defaultValueBox: Box[MyType] = Empty
override def toString = valueBox match {
case Full(null)|null => "null"
case Full(v) => v.toString
case _ => defaultValueBox.map(v => if (v != null) v.toString else "null") openOr ""
}
}
/**
* A simple field that can store and retreive a value of a given type
*/
trait Field[ThisType, OwnerType <: Record[OwnerType]] extends OwnedField[OwnerType] with TypedField[ThisType] {
def apply(in: MyType): OwnerType = apply(Full(in))
def apply(in: Box[MyType]): OwnerType = if (owner.meta.mutable_?) {
this.setBox(in)
owner
} else {
owner.meta.createWithMutableField(owner, this, in)
}
}
/**
* Mix in to a field to change its form display to be formatted with the label aside.
*
* E.g.
*
*
* { control }
*
*/
trait DisplayWithLabel[OwnerType <: Record[OwnerType]] extends OwnedField[OwnerType] {
override abstract def toForm: Box[NodeSeq] =
for (id <- uniqueFieldId; control <- super.toForm)
yield
{ control }
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