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
Related
I needed to add enum description for schema of a request in swagger, so I defined this filter :
public class EnumSchemaFilter : ISchemaFilter
{
public void Apply(OpenApiSchema model, SchemaFilterContext context)
{
if (context.Type.IsEnum)
{
model.Enum.Clear();
var names = Enum.GetNames(context.Type);
names
.ToList()
.ForEach(n => model.Enum.Add(new OpenApiString($"{n} : {(int)Enum.Parse(context.Type, n)}")));
model.Example = new OpenApiInteger((int)Enum.Parse(context.Type, names[0]));
}
}
}
However the issue here is that when I want to try that enum in a get request, I see the following option :
Is there a way to change this to only show enum integer values when user want to select ?
I could solve the issue by defining a custom ParametersFilter :
public class SchemaParametersFilter : IParameterFilter
{
public void Apply(OpenApiParameter parameter, ParameterFilterContext context)
{
var type = context.ParameterInfo?.ParameterType;
if (type == null)
return;
if (type.IsEnum && parameter.In == ParameterLocation.Query)
{
var names = Enum.GetNames(type);
parameter.Schema.Enum = names.OfType<string>().Select(p => new OpenApiInteger((int)Enum.Parse(type, p))).ToList<IOpenApiAny>();
}
}
}
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);
Trying to save selections from a CheckBoxList as a comma-separated list (string) in DB (one or more choices selected). I am using a proxy in order to save as a string because otherwise I'd have to create separate tables in the DB for a relation - the work is not worth it for this simple scenario and I was hoping that I could just convert it to a string and avoid that.
The CheckBoxList uses an enum for it's choices:
public enum Selection
{
Selection1,
Selection2,
Selection3
}
Not to be convoluted, but I use [Display(Name="Choice 1")] and an extension class to display something friendly on the UI. Not sure if I can save that string instead of just the enum, although I think if I save as enum it's not a big deal for me to "display" the friendly string on UI on some confirmation page.
This is the "Record" class that saves a string in the DB:
public virtual string MyCheckBox { get; set; }
This is the "Proxy", which is some sample I found but not directly dealing with enum, and which uses IEnumerable<string> (or should it be IEnumerable<Selection>?):
public IEnumerable<string> MyCheckBox
{
get
{
if (String.IsNullOrWhiteSpace(Record.MyCheckBox)) return new string[] { };
return Record
.MyCheckBox
.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
.Select(r => r.Trim())
.Where(r => !String.IsNullOrEmpty(r));
}
set
{
Record.MyCheckBox = value == null ? null : String.Join(",", value);
}
}
To save in the DB, I am trying to do this in a create class:
proxy.MyCheckBox = record.MyCheckBox; //getting error here
but am getting the error:
Cannot implicitly convert 'string' to System.Collections.Generic.IEnumerable'
I don't know, if it's possible or better, to use Parse or ToString from the API for enum values.
I know that doing something like this will store whatever I put in the ("") into the DB, so it's just a matter of figuring out how to overcome the error (or, if there is an alternative):
proxy.MyCheckBox = new[] {"foo", "bar"};
I am not good with this stuff and have just been digging and digging to come up with a solution. Any help is much appreciated.
You can accomplish this using a custom user type. The example below uses an ISet<string> on the class and stores the values as a delimited string.
[Serializable]
public class CommaDelimitedSet : IUserType
{
const string delimiter = ",";
#region IUserType Members
public new bool Equals(object x, object y)
{
if (ReferenceEquals(x, y))
{
return true;
}
var xSet = x as ISet<string>;
var ySet = y as ISet<string>;
if (xSet == null || ySet == null)
{
return false;
}
// compare set contents
return xSet.Except(ySet).Count() == 0 && ySet.Except(xSet).Count() == 0;
}
public int GetHashCode(object x)
{
return x.GetHashCode();
}
public object NullSafeGet(IDataReader rs, string[] names, object owner)
{
var outValue = NHibernateUtil.String.NullSafeGet(rs, names[0]) as string;
if (string.IsNullOrEmpty(outValue))
{
return new HashSet<string>();
}
else
{
var splitArray = outValue.Split(new[] {Delimiter}, StringSplitOptions.RemoveEmptyEntries);
return new HashSet<string>(splitArray);
}
}
public void NullSafeSet(IDbCommand cmd, object value, int index)
{
var inValue = value as ISet<string>;
object setValue = inValue == null ? null : string.Join(Delimiter, inValue);
NHibernateUtil.String.NullSafeSet(cmd, setValue, index);
}
public object DeepCopy(object value)
{
// return new ISet so that Equals can work
// see http://www.mail-archive.com/nhusers#googlegroups.com/msg11054.html
var set = value as ISet<string>;
if (set == null)
{
return null;
}
return new HashSet<string>(set);
}
public object Replace(object original, object target, object owner)
{
return original;
}
public object Assemble(object cached, object owner)
{
return DeepCopy(cached);
}
public object Disassemble(object value)
{
return DeepCopy(value);
}
public SqlType[] SqlTypes
{
get { return new[] {new SqlType(DbType.String)}; }
}
public Type ReturnedType
{
get { return typeof(ISet<string>); }
}
public bool IsMutable
{
get { return false; }
}
#endregion
}
Usage in mapping file:
Map(x => x.CheckboxValues.CustomType<CommaDelimitedSet>();
I want to replicate what StackOverflow does with its URLs.
For example:
Hidden Features of C#? - (Hidden Features of C#?)
or
Hidden Features of C#? - (Hidden Features of C#?)
Will Take you to the same page but when they return to the browser the first one is always returned.
How do you implement the change so the larger URL is returned?
The way that I've handled this before is to have two routes, registered in this order
routes.MapRoute(
null,
"questions/{id}/{title}",
new { controller = "Questions", action = "Index" },
new { id = #"\d+", title = #"[\w\-]*" });
routes.MapRoute(
null,
"questions/{id}",
new { controller = "Questions", action = "Index" },
new { id = #"\d+" });
now in the controller action,
public class QuestionsController
{
private readonly IQuestionRepository _questionRepo;
public QuestionsController(IQuestionRepository questionRepo)
{
_questionRepo = questionRepo;
}
public ActionResult Index(int id, string title)
{
var question = _questionRepo.Get(id);
if (string.IsNullOrWhiteSpace(title) || title != question.Title.ToSlug())
{
return RedirectToAction("Index", new { id, title = question.Title.ToSlug() }).AsMovedPermanently();
}
return View(question);
}
}
We'll permanently redirect to the URL that contains the title slug (lowercase title with hyphens as separators) if we only have the id. We also make sure that the title passed is the correct one by checking it against the slugged version of the question title, thereby creating a canonical URL for the question that contains both the id and the correct title slug.
A couple of the helpers used
public static class PermanentRedirectionExtensions
{
public static PermanentRedirectToRouteResult AsMovedPermanently
(this RedirectToRouteResult redirection)
{
return new PermanentRedirectToRouteResult(redirection);
}
}
public class PermanentRedirectToRouteResult : ActionResult
{
public RedirectToRouteResult Redirection { get; private set; }
public PermanentRedirectToRouteResult(RedirectToRouteResult redirection)
{
this.Redirection = redirection;
}
public override void ExecuteResult(ControllerContext context)
{
// After setting up a normal redirection, switch it to a 301
Redirection.ExecuteResult(context);
context.HttpContext.Response.StatusCode = 301;
context.HttpContext.Response.Status = "301 Moved Permanently";
}
}
public static class StringExtensions
{
private static readonly Encoding Encoding = Encoding.GetEncoding("Cyrillic");
public static string RemoveAccent(this string value)
{
byte[] bytes = Encoding.GetBytes(value);
return Encoding.ASCII.GetString(bytes);
}
public static string ToSlug(this string value)
{
if (string.IsNullOrWhiteSpace(value))
{
return string.Empty;
}
var str = value.RemoveAccent().ToLowerInvariant();
str = Regex.Replace(str, #"[^a-z0-9\s-]", "");
str = Regex.Replace(str, #"\s+", " ").Trim();
str = str.Substring(0, str.Length <= 200 ? str.Length : 200).Trim();
str = Regex.Replace(str, #"\s", "-");
str = Regex.Replace(str, #"-+", "-");
return str;
}
}
I've got the following classes:
public class SupplierCategory : IEquatable<SupplierCategory>
{
public string Name { get; set; }
public string Parent { get; set; }
#region IEquatable<SupplierCategory> Members
public bool Equals(SupplierCategory other)
{
return this.Name == other.Name && this.Parent == other.Parent;
}
#endregion
}
public class CategoryPathComparer : IEqualityComparer<List<SupplierCategory>>
{
#region IEqualityComparer<List<SupplierCategory>> Members
public bool Equals(List<SupplierCategory> x, List<SupplierCategory> y)
{
return x.SequenceEqual(y);
}
public int GetHashCode(List<SupplierCategory> obj)
{
return obj.GetHashCode();
}
#endregion
}
And i'm using the following linq query:
CategoryPathComparer comparer = new CategoryPathComparer();
List<List<SupplierCategory>> categoryPaths = (from i in infoList
select
new List<SupplierCategory>() {
new SupplierCategory() { Name = i[3] },
new SupplierCategory() { Name = i[4], Parent = i[3] },
new SupplierCategory() { Name = i[5], Parent = i[4] }}).Distinct(comparer).ToList();
But the distinct does not do what I want it to do, as the following code demonstrates:
comp.Equals(categoryPaths[0], categoryPaths[1]); //returns True
Am I using this in a wrong way? why are they not compared as I intend them to?
Edit:
To demonstrate the the comparer does work, the following returns true as it should:
List<SupplierCategory> list1 = new List<SupplierCategory>() {
new SupplierCategory() { Name = "Cat1" },
new SupplierCategory() { Name = "Cat2", Parent = "Cat1" },
new SupplierCategory() { Name = "Cat3", Parent = "Cat2" }
};
List<SupplierCategory> list1 = new List<SupplierCategory>() {
new SupplierCategory() { Name = "Cat1" },
new SupplierCategory() { Name = "Cat2", Parent = "Cat1" },
new SupplierCategory() { Name = "Cat3", Parent = "Cat2" }
};
CategoryPathComparer comp = new CategoryPathComparer();
Console.WriteLine(comp.Equals(list1, list2).ToString());
Your problem is that you didn't implement IEqualityComparer correctly.
When you implement IEqualityComparer<T>, you must implement GetHashCode so that any two equal objects have the same hashcode.
Otherwise, you will get incorrect behavior, as you're seeing here.
You should implement GetHashCode as follows: (courtesy of this answer)
public int GetHashCode(List<SupplierCategory> obj) {
int hash = 17;
foreach(var value in obj)
hash = hash * 23 + obj.GetHashCode();
return hash;
}
You also need to override GetHashCode in SupplierCategory to be consistent. For example:
public override int GetHashCode() {
int hash = 17;
hash = hash * 23 + Name.GetHashCode();
hash = hash * 23 + Parent.GetHashCode();
return hash;
}
Finally, although you don't need to, you should probably override Equals in SupplierCategory and make it call the Equals method you implemented for IEquatable.
Actually, this issue is even covered in documentation:
http://msdn.microsoft.com/en-us/library/bb338049.aspx.