I have 4 fields that takes a price (BigDecimal) but only one of them should contain a price. If price2 contains 255.95 and someone want's to enter a price in price1 Then this should be rejected with a message which says that you have to clean the other (price2 in this case)
I tried to do that in the domain but it didn't work for me.
An example:
class Author {
def String name
def String email
def BigDecimal price1
def BigDecimal price2
def BigDecimal price3
// static hasMany = [books: Book]
static constraints = {
name nullable:true
email nullable:true
price1(nullable:true,
validator: { val, obj ->
(obj.price2==null) and (obj.price3 == null) })
price2(nullable:true,
validator: { val, obj ->
(obj.price1==null) and (obj.price3 == null) })
price3(nullable:true,
validator: { val, obj ->
(obj.price1==null) and (obj.price2 == null) })
}
static mapping = {
name column: "AuthorName", sqltype:"char", length:25
}
String toString() {
return name
}
def beforeValidate() {
}
}
I get this error:
groovy.lang.MissingMethodException: No signature of method: masterdetail.Author.and() is applicable for argument types: (java.lang.Boolean) values: [true]
Possible solutions: any(), any(groovy.lang.Closure), find(), find(groovy.lang.Closure), find(java.lang.String), find(masterdetail.Author)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:58)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:81)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:52)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:154)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:166)
at masterdetail.Author$__clinit__closure1$_closure3.doCall(Author.groovy:16)
So, what to do?
Finally I solved the problem with some help fro doelleri.
I edited the question so it contains the final solution.
Related
I'm trying to work with the reddit JSON API. There are post data objects that contain a field called edited which may contain a boolean false if the post hasn't been edited, or a timestamp int if the post was edited.
Sometimes a boolean:
{
"edited": false,
"title": "Title 1"
}
Sometimes an int:
{
"edited": 1234567890,
"title": "Title 2"
}
When trying to parse the JSON where the POJO has the field set to int, I get an error: JsonDataException: Expected an int but was BOOLEAN...
How can I deal with this using Moshi?
I also ran into a similar problem where I had fields that were sometimes booleans, and sometimes ints. I wanted them to always be ints. Here's how I solved it with Moshi and kotlin:
Make a new annotation that you will use on fields to should convert from boolean to int
#JsonQualifier
#Retention(AnnotationRetention.RUNTIME)
#Target(AnnotationTarget.FIELD, AnnotationTarget.VALUE_PARAMETER, AnnotationTarget.FUNCTION)
annotation class ForceToInt
internal class ForceToIntJsonAdapter {
#ToJson
fun toJson(#ForceToInt i: Int): Int {
return i
}
#FromJson
#ForceToInt
fun fromJson(reader: JsonReader): Int {
return when (reader.peek()) {
JsonReader.Token.NUMBER -> reader.nextInt()
JsonReader.Token.BOOLEAN -> if (reader.nextBoolean()) 1 else 0
else -> {
reader.skipValue() // or throw
0
}
}
}
}
Use this annotation on the fields that you want to force to int:
#JsonClass(generateAdapter = true)
data class Discovery(
#Json(name = "id") val id: String = -1,
#ForceToInt #Json(name = "thanked") val thanked: Int = 0
)
The easy way might be to make your Java edited field an Object type.
The better way for performance, error catching, and appliaction usage is to use a custom JsonAdapter.
Example (edit as needed):
public final class Foo {
public final boolean edited;
public final int editedNumber;
public final String title;
public static final Object JSON_ADAPTER = new Object() {
final JsonReader.Options options = JsonReader.Options.of("edited", "title");
#FromJson Foo fromJson(JsonReader reader) throws IOException {
reader.beginObject();
boolean edited = true;
int editedNumber = -1;
String title = "";
while (reader.hasNext()) {
switch (reader.selectName(options)) {
case 0:
if (reader.peek() == JsonReader.Token.BOOLEAN) {
edited = reader.nextBoolean();
} else {
editedNumber = reader.nextInt();
}
break;
case 1:
title = reader.nextString();
break;
case -1:
reader.nextName();
reader.skipValue();
default:
throw new AssertionError();
}
}
reader.endObject();
return new Foo(edited, editedNumber, title);
}
#ToJson void toJson(JsonWriter writer, Foo value) throws IOException {
writer.beginObject();
writer.name("edited");
if (value.edited) {
writer.value(value.editedNumber);
} else {
writer.value(false);
}
writer.name("title");
writer.value(value.title);
writer.endObject();
}
};
Foo(boolean edited, int editedNumber, String title) {
this.edited = edited;
this.editedNumber = editedNumber;
this.title = title;
}
}
Don't forget to register the adapter on your Moshi instance.
Moshi moshi = new Moshi.Builder().add(Foo.JSON_ADAPTER).build();
JsonAdapter<Foo> fooAdapter = moshi.adapter(Foo.class);
I began learn Groovy, and faced the challenge.
I have this code, that stores meta-data to object:
class Meta {
final MetaItem name
final MetaItem description
// ...
// And more fields with type MetaItem
// ...
Meta() {
name = new MetaItem("name")
description = new MetaItem("description")
}
void setName(String name) {
this.name.value = name
}
String getName() {
return this.name.value
}
void setDescription(String description) {
this.description.value = description
}
String getDescription() {
return this.description.value
}
// ...
// And more methods. Two for each field
// ...
}
class MetaItem {
private final def id
def value
MetaItem(String id) {
this.id = id
}
}
// Validating
def meta = new Meta()
assert meta.name == null
assert meta.description == null
meta.with {
name = "Name"
description = "Desc"
}
assert meta.name == "Name"
assert meta.description == "Desc"
print "Success!"
As you can see from the code, it increases quicly in volumes when new fields are added, because for each field you need to add two methods. Can this somehow be optimized? Redirect the assignment operation from object to his member. I've looked on Delegate, but this is not what I need.
P.S. I can't use access by .value because this class is used in Gradle extension and I need to configure it like this:
myExtension {
meta {
name = "Name"
description = "Desc"
// And many others
}
}
P.P.S. Sorry for my bad english, it's not my first language
What is the problem with the code below?
var newContextElementCollection = new List<NewContextElements>();
var res = from eleCollection in newContextElementCollection
where eleCollection.Property.Except(new List<string> { "Password", "Some Other Value" })
select eleCollection;
The NewContextElementCollection class:
public class NewContextElements
{
public string Property { get; set; }
public string Value { get; set; }
}
I am getting this error:
Instance argument: cannot convert from 'string' to
'System.Linq.IQueryable'
Error 2 'string' does not contain a definition for 'Except' and the best extension
method overload 'System.Linq.Queryable.Except(System.Linq.IQueryable,
System.Collections.Generic.IEnumerable)' has some invalid arguments
Property is a string, not an IEnumerable<string>, which is what your Except clause can work on.
var res= from eleCollection in newContextElementCollection
where eleCollection.Property != "Password"
select eleCollection;
var excluded = new List<string> { "Password","Some Other Value" };
var res = newContextElementCollection.Where(m => !excluded.Contains(m.Property));
I want to retrieve a specific record using IQueryable. But i get error 'No generic method 'Where' on type 'System.Linq.Queryable' is compatible with the supplied type arguments and arguments. No type arguments should be provided if the method is non-generic.'. I got the selected row id, but I cannot display it out. Here is my code.
internal static IQueryable GetRecordsFromPrimaryKeys(this IQueryable datasource, List<FilterDescriptor> primaryKeys)
{
IQueryable data = datasource;
ParameterExpression paramExp = null;
bool firstLoop = false;
System.Linq.Expressions.Expression predicate = null;
var RecordType = datasource.GetObjectType();
paramExp = RecordType.Parameter();
foreach (FilterDescriptor primaryKey in primaryKeys)
{
if (!(firstLoop))
{
predicate = data.Predicate(paramExp, primaryKey.ColumnName, primaryKey.Value, FilterType.Equals, false, RecordType);
firstLoop = true;
}
else
{
predicate = predicate.AndPredicate(data.Predicate(paramExp, primaryKey.ColumnName, primaryKey.Value, FilterType.Equals, false, RecordType));
}
}
if (paramExp != null && predicate != null)
{
var lambda = Expression.Lambda(predicate, paramExp);
data = data.Provider.CreateQuery(
Expression.Call(
typeof(Queryable),
"Where",
new Type[] { data.ElementType },
data.Expression,
lambda
)
);
}
return data;
}
My Code works well for IEnumerable/IQueryable/ICollection . But it throws the exception when i specify the class with the keyword virtual and type as ICollection. My code is
public class RoomType
{
public int ID { get; set; }
[MaxLength(10, ErrorMessage = "Room code cannot be longer than 10 characters.")]
public string Code { get; set; }
[MaxLength(50, ErrorMessage = "Room name cannot be longer than 50 characters.")]
public string Name { get; set; }
public virtual ICollection<RoomCategory> RoomCategories { get; set; }
}
Some random values gets appended to 'RecordType' while using the keyword 'virtual'. I think this leads to the exception. Still searching for the solution.
I don't know what is going wrong . Any suggestions welcome.
Thanks.
I just ran into a similar situation. The problem stems from the fact that in some cases you're dealing with the "proxy" not the actual entity. So, you want to make sure that RecordType matches data.ElementType.
try:
var recordType = datasource.GetObjectType();
// make sure we have the correct type (not the proxy)
if (recordType.BaseType.Name != "Object")
recordType = recordType.BaseType;
Or better yet, try:
var recordType = data.ElementType
Try to use typeof(Enumerable) instead of typeof(Queryable)
Operator overloading is working perfect in C# code, since I am trying in the following way.
**
public class HostCode
{
public string Code { get; set; }
public string Name { get; set; }
public static bool operator ==(HostCode hc1, HostCode hc2)
{
return hc1.Code == hc2.Code;
}
public static bool operator !=(HostCode hc1, HostCode hc2)
{
return true;
}
}**
I have a clas called HostCode and it contains 2 overloading methods (one for '==' and another for '!=')
And I created a collection of Host Codes below.
**var hostCodes = new List<HostCode>()
{
new HostCode(){ Code = "1", Name = "sreekanth" },
new HostCode(){ Code = "2", Name = "sajan" },
new HostCode(){ Code = "3", Name = "mathew" },
new HostCode(){ Code = "4", Name = "sachin" }
};**
***var hc = new HostCode() { Code = "1", Name = "sreekanth" };***
***var isEq = hostCodes[1] == hc;***
when I am trying like above, the respective operator method fired in HostCode class (in this case it is '=='). So that I can write my custom logic there.
But if Iam trying with a Linq query as below, it is not firing. But in this case also Iam comparing 2 objects having same type.
**var isEqual = from obj in hostCodes where (HostCode)obj == (HostCode)hc select obj;**
Can anyone please help me to find out a way which I can compare 2 objects by Linq queries?
You can use IEqualityComparer or override equals for this purpose.
public class HostCode
{
....
public override bool Equals(object obj)
{
if (ReferenceEquals(null, obj)) return false;
if (ReferenceEquals(this, obj)) return true;
return obj as HostCode == null ? false : (obj as HostCode).Code == Code;
}
}
And IEqualityComparer usage is when you have some equality on object and in some functions like Contain, ... you want use some specific equality:
public class EqualityComparer : IEqualityComparer<HostCode >
{
public bool Equals(HostCode x, HostCode y)
{
return y.ID == x.ID;
}
public int GetHashCode(string obj)
{
return obj.GetHashCode();
}
}
Since your question is "how should I compare them for this to work" I would answer "you should overload and use .Equals() instead of =="
And what's with your overload definition of !=?