I am a bit stuck, hoping for guidance. I have 2 tables, Header and Details. However, the details is a bit different than most, and allows for a way to dynamically store data.: Yes, I am aware that I can create a table storing the details in the standard fashion, but the nature of the app needs to be more dynamic on the database side. I also realize I will have to modify the DTOs for different incarnations of the app, but this model is what I need to accomplish.
public class Header
{
public int Id { get; set; }
public string HeaderName { get; set; }
public ICollection<Detail> Details { get; set; }
}
public class Detail
{
public int Id { get; set; }
public int HeaderId { get; set; }
public string FieldName { get; set; }
public string FieldProperty { get; set; }
}
I want to use the following DTOs:
public class DataForDisplayDto
{
public int Id { get; set; }
public string HeaderName { get; set; }
public string TaskToPerform { get; set; }
public string Location { get; set; }
}
public class DataForCreationDto
{
public string HeaderName { get; set; }
public string TaskToPerform { get; set; }
public string Location { get; set; }
}
The data would be stored in the details in this fashion:
{
"FieldName": "tasktoperform",
"FieldProperty": "Thing to Do"
},
{
"FieldName": "location",
"FieldProperty": "Over there"
}
I am trying to use the Automapper to make it so I can read and write to the database using the DTOs, but I think I may be trying something it can't do.
Is there an article or something that anyone knows about that can point me in the direction to go? Or even the right keywords to search online for it. Is it even possible?
I suppose if it is not possible, I will have to do things a bit more manually, which is the last option, I am just hoping to do this with Automapper.
Thanks!
How about deriving your DTO from a base class that uses reflection to generate a mapping, and cache that mapping.
This way your DTO need only inherit a base class.
Related
I've been trying to figure out how to do the following (although my research did not help): I have the these three classes:
public abstract class Classifier
{
public int ClassifierId { get; set; }
public string ClassifierName { get; set; }
public DateTime DateAdded { get; set; }
}
public class ManualClassifier : Classifier
{
public int ManualClassifierId { get; set; }
public string user_name { get; set; }
public string userName { get; set; }
public string firstName { get; set; }
public string lastName { get; set; }
public string email { get; set; }
public string password { get; set; }
}
public class ToolClassifier : Classifier
{
public int ToolId { get; set; }
public string ToolName { get; set; }
}
Both the ManualClassifier and ToolClassifer inherit from Classifier. I'm using EF Core to map this to a database but the question is the following: I've already searched a bit and I must make use of a descriminator which basically is an implicitly created column that will say the type of, in this case, classifier. So far so good. The issue arises when I have a property called ManualClassifierId as well as a ToolId. I want this two properties to map to the ClassifierId property. So in the table representing the entity Classifier, the ClassifierId property will either be the ManualClassifierId or the ToolId.
How can I achieve this mapping? Also, this solution would mean that both child classes would both have empty fileds in the tables (due to inheriting the three properties from the Classifier class). Is there a better solution? Perhaps just erase the Id's from both child classes a let them inherit the parent one?
Thank you in advance!
To use the same column name in both classes, you can add a Column attribute to both properties. Then they will both use that column name in the database. See ColumnAttribute(String).
Use it like this:
public class ManualClassifier : Classifier
{
[Column(Name="ClassifierId")]
public int ManualClassifierId { get; set; }
...........
}
Do the same with ToolId.
So I am using one of the google Id API; https://developers.google.com/instance-id/reference/server#manage_registration_tokens_for_push_subscriptions
I have previously been fortunate to have API that had WDSL or similar and been easy to parse into a class.
But the JSON I got back I can not parse easily.
{
"connectDate":"2018-02-12",
"application":"com.chrome.windows",
"subtype":"wp:https://xxxxxxxxxxxxxxxxxxx",
"authorizedEntity":"xxxxxx",
"rel":{
"topics":{
"movies":{
"addDate":"2018-01-26"
},
"anotherTopic":{
"addDate":"2018-02-12"
}
}
},
"connectionType":"WIFI",
"platform":"WEBPUSH"
}
Movies and anotherTopics are the topics I created so I can't add them to my class . Or can I?
There are of course ways to do it treating the json as string and using regex or going through the node as a dynamic object (dynamic dyn = JsonConvert.DeserializeObject(content);) but ideally I think it should be a dictionary (I think at least) but can not see how.
And as this is Google I assume there is more standard way to handle this kind of JSON.
I have tried creating a dictionary which I couldn't get working.
Stepping through the nodes I can get the data but end up with code like
DateTime.Parse(((Newtonsoft.Json.Linq.JValue)((Newtonsoft.Json.Linq.JProperty)((Newtonsoft.Json.Linq.JContainer)(obj.First)).First).Value).Value.ToString())
I have tried to look for similar JSON parsing exampels but I can not find any.
I did not share my attempt to extract the data in my first edit as I don't think that is the way to do it; it is a hack.
I created a class for it
public class SubscriptionDetails
{
public DateTime connectDate { get; set; }
public string application { get; set; }
public string subtype { get; set; }
public string authorizedEntity { get; set; }
public string connectionType { get; set; }
public string platform { get; set; }
public topics rel { get; set; }
}
But I am stuck when it comes to defining the subclass topics.
So I tried
public class topics : Dictionary<string, object>
which results in one dictionary entry with key topics?
the other option requires a dictionary name
public class topics
{
public Dictionary<string, Dictionary<string, string>> DUMMY { get; set; }
}
So thanks to the suggestion from Jamiec I got on the right track.
Of course already the node rel is a dictionary with one item called topics.
So need a few classes to parse the entire thing:
public class SubscriptionDetails
{
public DateTime connectDate { get; set; }
public string application { get; set; }
public string subtype { get; set; }
public string authorizedEntity { get; set; }
public string connectionType { get; set; }
public string platform { get; set; }
public Dictionary<string, topicItems> rel { get; set; }
}
public class topicItems : Dictionary<string, topicData> { }
public class topicData
{
public DateTime addDate { get; set; }
}
But if they add another node to rel in addition to 'topics' this most likely will crash.
Just doesn't seem to be a very good way to structure the data and the deserialised class isn't very user friendly either..
Anyway it works (for now)
I'm not sure the best way to create this kind of relation ship. I have these two entities for this example.
Person & Address
public class Person
{
public string Name { get; set; }
public virtual ICollection<PersonAddressLink> HomeAddresses { get; set; }
public virtual ICollection<PersonAddressLink> WorkAddresses { get; set; }
}
public class Address
{
public string AddressString {get; set; }
public virtual ICollection<Person> People { get; set; }
}
and a link table, needed because it contains other info.
public class PersonAddressLink
{
public Address HomeAddress { get; set; }
public Address WorkAddress { get; set; }
public int SomeOtherInt { get; set; }
public string SomeOtherString { get; set; }
}
The problem is EF doesn't know how to separate the entities on person.HomeAddresses / person.WorkAddresses. I have tried mergin HomeAddress & WorkAddresses into a single collection like this:
public virtual ICollection<PersonAddressLink> WorkAddresses { get; set; }
but it still won't work.
I'm just looking for advice on how to lay something like this out to get it working with EF Code first.
I hope that makes sense.
Thanks
Late reply but I got the mapping correct by creating the table in SQL Management studio and using the reverse engineer functionality which generated the Code First. I need to use two separate entities.
I have four MVC model layer domain classes.
namespace MvcMobile.Models.BusinessObject
{
public class Speaker
{
public int SpeakerID { get; set; }
public string SpeakerName { get; set; }
}
public class Tag
{
public int TagID { get; set; }
public string TagName { get; set; }
}
public class Seminar
{
public string Seminar_Code { get; set; }
public string Title { get; set; }
public string Description { get; set; }
public string Room { get; set; }
}
public class Seminar_Detail
{
public string Seminar_Code { get; set; }
public int SpeakerID { get; set; }
public int TagID { get; set; }
public string DateAndTime { get; set; }
}
}
I would like to make CRUD operation by using these classes. So I create two VeiwModel Classes.
namespace MvcMobile.ViewModel
{
public class Seminar_Root_ViewModel
{
public Seminar_Subsidiary_ViewModel Seminars { get; set; }
public List<Speaker> Speakers { get; set; }
public List<Tag> Tags { get; set; }
}
public class Seminar_Subsidiary_ViewModel
{
public Seminar Seminar { get; set; }
public List<Seminar_Detail> Seminar_Detail { get; set; }
}
}
For Controller layer, I consider that I will use Seminar_Root_ViewModel to make the whole CRUD operation processes.
What I would like to ask is that Is this proper way or correct way?
If you have more elegant way to make model layer and ViewModel layer, Please let me get suggestion.
Every suggestion will be appreciated.
[updated]
Let's assume that I make master-Detail form design.
Speaker and Tag are just look-up tables for dropdownlist or some controls like that.
Seminar is Master Data and Seminar_Detail will be Item Grid Data.
So As for this scenario, all of this classes are needed for this program.
Please let me know if my thinking is wrong.
The only thing I can see is if you are not going to re-use your Seminar_Subsidiary_ViewModel view model you could skip it.
If you are going to need those two properties Seminar and Seminar_Detail on another view or ajax call, it's perfectly fine to have that kind of separation.
Personally I'm not a huge fan of _ on class name, but that have nothing to do with the question.
Consider this Poco:
public class User
{
public int Id { get; set; }
public string Username { get; set; }
public string Fullname { get; set; }
}
Now i want to implement a follow technique where a user may follow other users so basically its self Many to Many relationship
problem is i don't know how exactly i can achieve this in Entity Framework Code-First ?
I thought of a linker Table :
public class UserFollow
{
public int Id { get; set; }
public int Follower { get; set; }
public int Following { get; set; }
public DateTime FollowDate { get; set; }
}
i want to be able to get All Followers and Following from every User Object?
This is quite simple using EF code-first as you only need the User POCO:
public class User
{
public int Id { get; set; }
public string Username { get; set; }
public string Fullname { get; set; }
public ICollection<User> FollowedUsers { get; set; }
}
The collection means that a User is related to other users.
PS: I noted you added a timestamp in your solution example. To achieve that you should still add the collection changing the generic type to whatever suits your needs.
Hope it helps.