使用表格通用导出到CSV

Question

目标:

我们的应用程序是使用多种类型构建的(例如Person,PersonSite(ICollection),Site - 我选择了那些类,因为它们有关系).我们想要做的是能够从excel表中的第一个类型(Person)导出一些属性,然后从同一个excel文件中的第二个类型(PersonSite)导出一些其他属性,但是在同一个新表中导出片.

结果应如下所示:

 _________________   ________________________   ________________
|                 | |                        | |                |
|PERSON PROPERTIES| | PERSONSITE PROPERTIES  | |SITE PROPERTIES |
|_________________| |________________________| |________________|
|  Name Person 1  | |Relation type for item 1| | Name for item 1|
|_________________| |________________________| |________________|
                    |Relation type for item 2| | Name for item 2|
                    |________________________| |________________|
                    |Relation type for item 3| | Name for item 3|
                    |________________________| |________________|
 _________________   ________________________   ________________
|  Name Person 2  | |Relation type for item 1| | Name for item 1|
|_________________| |________________________| |________________|
                    |Relation type for item 2| | Name for item 1|
                    |________________________| |________________|

因此,对于列表中包含的每个PersonSite,我们想要创建一个将在Person表之后插入的表.

所以这就是看Person类(类的子集)的方式:

public class Person : IObject
{
   public ICollection<PersonSite> PersonSites {get;set;}
}

现在是PersonSite类(子集):

public class PersonSite : IObject
{
   public Person Person {get;set;}
   public Site Site {get;set;}
   public RelationType RelationType {get;set;}
}

Site类(子集):

public class Site : IObject
{
   public ICollection<PersonSite> PersonSites {get;set;}
}

所以我们决定编写一个CSVExporter类,它使用表达式来检索必须导出的属性.

这是我们必须实现的方案:

                    
                            ____
                           |    |0..*
 ______________          __|____|______       1..* _______________
| CSV EXPORTER |________| CSV TABLE (T)|__________| CSV COLUMN (T)|
|______________|        |______________|          |_______________|
                               |
                               |1..*
                         ______|________
                        | CSV ROWS (T)  |
                        |_______________|

因此,CSVTable使用IObject的泛型类型(在不同的类中使用).

一个表可以有多个表(例如,Person表有一个PersonSite表,PersonSite表有一个Site表).但是使用的类型是不同的,因为我们浏览不同的类(这些类必须有关系).

当添加一个子表,以一个表中,我们应当提供连接表达式将抓住正确类型的项从主项目(人=> Person.PersonSite)

所以我们为表编写了以下代码:

public class CSVExportTable<T>
    where T : IObject
{

    private Matrix<string> Matrix { get; set; }
    private ICollection<CSVExportTableColumn<T>> Columns { get; set; }
    private ICollection<CSVExportTableRow<T>> Rows { get; set; }
    private ICollection<CSVExportTable<IObject>> SubTables { get; set; }
    private Expression<Func<T, object>> Link { get; set; }


    public CSVExportTable()
    {
        this.Matrix = new Matrix<string>();
        this.Columns = new List<CSVExportTableColumn<T>>();
        this.SubTables = new List<CSVExportTable<IObject>>();
        this.Rows = new List<CSVExportTableRow<T>>();
    }

    public CSVExportTable<R> AddSubTable<R>(Expression<Func<T, object>> link) where R : IObject
    {
        /* This is where we create the link between the main table items and the subtable items (= where we retreive Person => Person.PersonSites as an ICollection<R> since the subtable has a different type (T != R but they have the same interface(IObject))*/
    }

    public void AddColumn(Expression<Func<T, object>> exportProperty)
    {
        this.Columns.Add(new CSVExportTableColumn<T>(exportProperty));
    }

    public Matrix<string> GenerateMatrix()
    {
        int rowIndex= 0;
        foreach (CSVExportTableRow<T> row in this.Rows)
        {
            int columnIndex = 0;
            foreach (CSVExportTableColumn<T> column in this.Columns)
            {
                this.Matrix = this.Matrix.AddValue(rowIndex, columnIndex, ((string)column.ExportProperty.Compile().DynamicInvoke(row.Item)));
                columnIndex++;
            }
            rowIndex++;
        }
        return this.Matrix;
    }

    public Matrix<string> ApplyTemplate(ICollection<T> items)
    {
        // Generate rows
        foreach (T item in items)
        {
            this.Rows.Add(new CSVExportTableRow<T>(item));
        }
        // Instantiate the matrix
        Matrix<string> matrix = new Matrix<string>();

        // Generate matrix for every row
        foreach (var row in this.Rows)
        {
            matrix = GenerateMatrix();
            // Generate matrix for every sub table
            foreach (var subTable in this.SubTables)
            {
                // This it where we should call ApplyTemplate for the current subTable with the elements that the link expression gave us(ICollection).
            }
        }
        return matrix;
    }
}

最后这里是CSVExportTableColumn类:

public class CSVExportTableColumn<T> where T : IObject
{
    public Expression<Func<T, object>> ExportProperty { get; set; }

    public CSVExportTableColumn(Expression<Func<T, object>> exportProperty)
    {
        this.ExportProperty = exportProperty;
    }
}

有没有人做过这样的事情？或者我们正走向错误的道路？如果这似乎是一个好路径,我们如何创建链接(关系)表达式并使用它来检索在最后一次调用时使用的正确项目？

Answer 1

抱歉耽搁了，

最后，我们让它像这样工作：

public Matrix<string> ApplyTemplate(object items)
    {
        ICollection<T> castedItems = new List<T>();
        // Cast items as a List<T>
        if (items is List<T>)
        {
            castedItems = (ICollection<T>)items;
        }
        else if (items is HashSet<T>)
        {
            castedItems = ((HashSet<T>)items).ToList();
        }
        // Generate rows
        foreach (T item in castedItems)
        {
            this.Rows.Add(new CSVExportTableRow<T>(item));
        }
        // Instantiate the matrix
        Matrix<string> matrix = new Matrix<string>();

        // Generate matrix for every row
        foreach (var row in this.Rows)
        {
            matrix = GenerateMatrix();
            // Generate matrix for every sub table
            foreach (var subTable in this.SubTables)
            {
                matrix = matrix.AddMatrix(subTable.ApplyTemplate(this.Link.Compile().DynamicInvoke(row.Item)));
            }
        }
        return matrix;
    }

这会将模板应用于任何子表。

希望这对其他人有用。