Persistor of a Serializer

We had this situation in my last project where we wanted to have some of our objects to get easily serialized into a specific table. Therefor we had to add up to the Serializer an new generic class that uses the Serializer to get the sream to put into a table.
In this example we have several classes like Article, Order, etc. and we wanted to give them a specific addition that would implement the Save and Load for all these classes. So we wanted to have something like this :

[Serializable]
public class Article : Persistor

and then later use it as follows:

// Read the last saved Article filter
private Article filter = Article.Load();

…
// and do something with it and finally save it back to Database

this.filter.Remove(e.Item.Key);
…
this.filter.Save();

Well, to achive that we implemented the Persistor class as follows:


using System;
using System.Collections.Generic;

/// <summary>
/// Provides the persistance methods for the filter classes.
/// It reads and writes the content in an xml format into the Filter table
/// </summary>
/// <typeparam name="T">The type of the filter. This type should derive from Persistor&lt;T&gt; and have an empty constructor</typeparam>
[Serializable]
public class Persistor<T>
    where T : Persistor<T>, new()
{
    /// <summary>
    /// Saves this filter as the default filter for the current user.
    /// </summary>
    public void Save()
    {
        // Serialize the current filter instance
        Serializer<T> serializer = new Serializer<T>();
        string xml = serializer.Serialize(this as T);

        // The filter class is a data class that handles the saveing of a record
        Data.Tables.Filter filter = Persistor<T>.LoadFilter(true);

        // Actual save to database
        filter.Value = xml;
        filter.Save();
    }

    /// <summary>
    /// Loads the default filter for the current table and user.
    /// </summary>
    public static T Load()
    {
        Tables.Filter filter = Persistor<T>.LoadFilter(false);

        // Deserialize
        T currentFilter = null;
        if (filter != null && !string.IsNullOrEmpty(filter.Value))
        {
            Serializer<T> serializer = new Serializer<T>();
            currentFilter = serializer.Deserialize(filter.Value);
        }
        else
        {
            currentFilter = new T();
        }

        return currentFilter;
    }

    /// <summary>
    /// Loads the Filter for the current user and table from the database.
    /// </summary>
    protected static Tables.Filter LoadFilter(bool createNew)
    {
        string tableId = typeof(T).Name;
        int userId = UserContext.Current.User.ID;

        // Load current filter, if available, otherwise create a new filter instance.
        Tables.Filter filter = Tables.Filter.GetForUserTable(userId, tableId);
        if (filter == null && createNew)
        {
            filter = new Data.Tables.Filter();
            filter.UserID = userId;
            filter.TableID = tableId;
        }

        return filter;
    }
}

Author: Pouya Panahy

Microsoft certified DevOps engineer with passion in analysing, designing and implementing solutions for Azure Cloud with hands-on experience in security and quality assurence.

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