Fluent CSV/XML Exporter for List
修改默认参数为重载后，VS2008可以正常编译.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;
using System.Reflection;
using System.IO;
using System.Xml;
namespace FluentListExporterColumns
{
public static class IEnumerableExtensions
{
/// <summary>
/// Exporter extension method for all IEnumerableOfT
/// </summary>
public static FluentExporter<T> GetExporter<T>(
this IEnumerable<T> source, String seperator) where T : class
{
return new FluentExporter<T>(source, seperator);
}
public static FluentExporter<T> GetExporter<T>(
this IEnumerable<T> source) where T : class
{
return new FluentExporter<T>(source, ",");
}
}
/// <summary>
/// Represents custom exportable column with a expression for the property name
/// and a custom format string
/// </summary>
public class ExportableColumn<T>
{
public Expression<Func<T, Object>> Func { get; private set; }
public String HeaderString { get; private set; }
public String CustomFormatString { get; private set; }
public ExportableColumn(
Expression<Func<T, Object>> func,
String headerString ,
String customFormatString)
{
this.Func = func;
this.HeaderString = headerString;
this.CustomFormatString = customFormatString;
}
public ExportableColumn(
Expression<Func<T, Object>> func)
{
this.Func = func;
this.HeaderString = "";
this.CustomFormatString = "";
}
}
/// <summary>
/// Exporter that uses Expression tree parsing to work out what values to export for
/// columns, and will use additional data as specified in the List of ExportableColumn
/// which defines whethere to use custom headers, or formatted output
/// </summary>
/// <typeparam name="T"></typeparam>
public class FluentExporter<T> where T : class
{
private List<ExportableColumn<T>> columns = new List<ExportableColumn<T>>();
private Dictionary<Expression<Func<T, Object>>, Func<T, Object>> compiledFuncLookup =
new Dictionary<Expression<Func<T, Object>>, Func<T, Object>>();
private List<String> headers = new List<String>();
private IEnumerable<T> sourceList;
private String seperator;
private bool doneHeaders;
public FluentExporter(IEnumerable<T> sourceList, String seperator)
{
this.sourceList = sourceList;
this.seperator = seperator;
}
public FluentExporter(IEnumerable<T> sourceList)
{
this.sourceList = sourceList;
this.seperator = ",";
}
public FluentExporter<T> AddExportableColumn(
Expression<Func<T, Object>> func,
String headerString ,
String customFormatString)
{
columns.Add(new ExportableColumn<T>(func,headerString,customFormatString));
return this;
}
public FluentExporter<T> AddExportableColumn(
Expression<Func<T, Object>> func,
String headerString)
{
columns.Add(new ExportableColumn<T>(func, headerString, ""));
return this;
}
public FluentExporter<T> AddExportableColumn(
Expression<Func<T, Object>> func)
{
columns.Add(new ExportableColumn<T>(func,"",""));
return this;
}
/// <summary>
/// Export all specified columns as a string,
/// using seperator and column data provided
/// where we may use custom or default headers
/// (depending on whether a custom header string was supplied)
/// where we may use custom fomatted column data or default data
/// (depending on whether a custom format string was supplied)
/// </summary>
public void AsCSVString(TextWriter writer)
{
if (columns.Count == 0)
throw new InvalidOperationException(
"You need to specify at least one column to export value");
foreach (T item in sourceList)
{
List<String> values = new List<String>();
foreach (ExportableColumn<T> exportableColumn in columns)
{
if (!doneHeaders)
{
if (String.IsNullOrEmpty(exportableColumn.HeaderString))
{
headers.Add(GetPropertyName(exportableColumn.Func));
}
else
{
headers.Add(exportableColumn.HeaderString);
}
Func<T, Object> func = exportableColumn.Func.Compile();
compiledFuncLookup.Add(exportableColumn.Func, func);
if (!String.IsNullOrEmpty(exportableColumn.CustomFormatString))
{
var value = func(item);
values.Add(value != null ?
String.Format(exportableColumn.CustomFormatString, value.ToString()) : "");
}
else
{
var value = func(item);
values.Add(value != null ? value.ToString() : "");
}
}
else
{
if (!String.IsNullOrEmpty(exportableColumn.CustomFormatString))
{
var value = compiledFuncLookup[exportableColumn.Func](item);
values.Add(value != null ?
String.Format(exportableColumn.CustomFormatString, value.ToString()) : "");
}
else
{
var value = compiledFuncLookup[exportableColumn.Func](item);
values.Add(value != null ? value.ToString() : "");
}
}
}
if (!doneHeaders)
{
writer.WriteLine(headers.Aggregate((start, end) => start + seperator + end));
doneHeaders = true;
}
writer.WriteLine(values.Aggregate((start, end) => start + seperator + end));
}
}
// <summary>
/// Export all specified columns as a XML string, using column data provided
/// and use custom headers depending on whether a custom header string was supplied.
/// Use custom formatted column data or default data depending on whether a custom format string was supplied.
/// </summary>
public void ToXML(XmlTextWriter writer)
{
if (columns.Count == 0)
throw new InvalidOperationException("You need to specify at least one element to export value");
foreach (T item in sourceList)
{
List<String> values = new List<String>();
foreach (ExportableColumn<T> exportableColumn in columns)
{
if (!doneHeaders)
{
if (String.IsNullOrEmpty(exportableColumn.HeaderString))
{
headers.Add(MakeXMLNameLegal(GetPropertyName(exportableColumn.Func)));
}
else
{
headers.Add(MakeXMLNameLegal(exportableColumn.HeaderString));
}
Func<T, Object> func = exportableColumn.Func.Compile();
compiledFuncLookup.Add(exportableColumn.Func, func);
if (!String.IsNullOrEmpty(exportableColumn.CustomFormatString))
{
var value = func(item);
values.Add(value != null ?
String.Format(exportableColumn.CustomFormatString, value.ToString()) : "");
}
else
{
var value = func(item);
values.Add(value != null ? value.ToString() : "");
}
}
else
{
if (!String.IsNullOrEmpty(exportableColumn.CustomFormatString))
{
var value = compiledFuncLookup[exportableColumn.Func](item);
values.Add(value != null ?
String.Format(exportableColumn.CustomFormatString, value.ToString()) : "");
}
else
{
var value = compiledFuncLookup[exportableColumn.Func](item);
values.Add(value != null ? value.ToString() : "");
}
}
}
if (!doneHeaders)
{
writer.Formatting = Formatting.Indented;
writer.WriteStartDocument(true);
writer.WriteProcessingInstruction("xml-stylesheet", "type='text/xsl' href='dump.xsl'");
writer.WriteComment("List Exporter dump");
// Write main document node and document properties
writer.WriteStartElement("dump");
writer.WriteAttributeString("date", DateTime.Now.ToString());
doneHeaders = true;
}
writer.WriteStartElement("item");
for (int i = 0; i < values.Count; i++)
{
writer.WriteStartElement(headers[i]);
writer.WriteString(values[i]);
writer.WriteEndElement();
}
writer.WriteEndElement();
}
writer.WriteEndElement();
writer.Flush();
}
/// <summary>
/// Export to file, using the AsCSVString() method to supply the exportable data
/// </summary>
public void WhichIsExportedToFileLocation(StreamWriter fileWriter)
{
AsCSVString(fileWriter);
}
/// <summary>
/// Gets a Name from an expression tree that is assumed to be a
/// MemberExpression
/// </summary>
private static string GetPropertyName<T>(
Expression<Func<T, Object>> propertyExpression)
{
var lambda = propertyExpression as LambdaExpression;
MemberExpression memberExpression;
if (lambda.Body is UnaryExpression)
{
var unaryExpression = lambda.Body as UnaryExpression;
memberExpression = unaryExpression.Operand as MemberExpression;
}
else
{
memberExpression = lambda.Body as MemberExpression;
}
var propertyInfo = memberExpression.Member as PropertyInfo;
return propertyInfo.Name;
}
private string MakeXMLNameLegal(string aString)
{
StringBuilder newName = new StringBuilder();
if (!char.IsLetter(aString[0]))
newName.Append("_");
// Must start with a letter or underscore.
for (int i = 0; i <= aString.Length - 1; i++)
{
if (char.IsLetter(aString[i]) || char.IsNumber(aString[i]))
{
newName.Append(aString[i]);
}
else
{
newName.Append("_");
}
}
return newName.ToString();
}
}
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;
using System.Reflection;
using System.IO;
using System.Xml;
namespace FluentListExporterColumns
{
public static class IEnumerableExtensions
{
/// <summary>
/// Exporter extension method for all IEnumerableOfT
/// </summary>
public static FluentExporter<T> GetExporter<T>(
this IEnumerable<T> source, String seperator) where T : class
{
return new FluentExporter<T>(source, seperator);
}
public static FluentExporter<T> GetExporter<T>(
this IEnumerable<T> source) where T : class
{
return new FluentExporter<T>(source, ",");
}
}
/// <summary>
/// Represents custom exportable column with a expression for the property name
/// and a custom format string
/// </summary>
public class ExportableColumn<T>
{
public Expression<Func<T, Object>> Func { get; private set; }
public String HeaderString { get; private set; }
public String CustomFormatString { get; private set; }
public ExportableColumn(
Expression<Func<T, Object>> func,
String headerString ,
String customFormatString)
{
this.Func = func;
this.HeaderString = headerString;
this.CustomFormatString = customFormatString;
}
public ExportableColumn(
Expression<Func<T, Object>> func)
{
this.Func = func;
this.HeaderString = "";
this.CustomFormatString = "";
}
}
/// <summary>
/// Exporter that uses Expression tree parsing to work out what values to export for
/// columns, and will use additional data as specified in the List of ExportableColumn
/// which defines whethere to use custom headers, or formatted output
/// </summary>
/// <typeparam name="T"></typeparam>
public class FluentExporter<T> where T : class
{
private List<ExportableColumn<T>> columns = new List<ExportableColumn<T>>();
private Dictionary<Expression<Func<T, Object>>, Func<T, Object>> compiledFuncLookup =
new Dictionary<Expression<Func<T, Object>>, Func<T, Object>>();
private List<String> headers = new List<String>();
private IEnumerable<T> sourceList;
private String seperator;
private bool doneHeaders;
public FluentExporter(IEnumerable<T> sourceList, String seperator)
{
this.sourceList = sourceList;
this.seperator = seperator;
}
public FluentExporter(IEnumerable<T> sourceList)
{
this.sourceList = sourceList;
this.seperator = ",";
}
public FluentExporter<T> AddExportableColumn(
Expression<Func<T, Object>> func,
String headerString ,
String customFormatString)
{
columns.Add(new ExportableColumn<T>(func,headerString,customFormatString));
return this;
}
public FluentExporter<T> AddExportableColumn(
Expression<Func<T, Object>> func,
String headerString)
{
columns.Add(new ExportableColumn<T>(func, headerString, ""));
return this;
}
public FluentExporter<T> AddExportableColumn(
Expression<Func<T, Object>> func)
{
columns.Add(new ExportableColumn<T>(func,"",""));
return this;
}
/// <summary>
/// Export all specified columns as a string,
/// using seperator and column data provided
/// where we may use custom or default headers
/// (depending on whether a custom header string was supplied)
/// where we may use custom fomatted column data or default data
/// (depending on whether a custom format string was supplied)
/// </summary>
public void AsCSVString(TextWriter writer)
{
if (columns.Count == 0)
throw new InvalidOperationException(
"You need to specify at least one column to export value");
foreach (T item in sourceList)
{
List<String> values = new List<String>();
foreach (ExportableColumn<T> exportableColumn in columns)
{
if (!doneHeaders)
{
if (String.IsNullOrEmpty(exportableColumn.HeaderString))
{
headers.Add(GetPropertyName(exportableColumn.Func));
}
else
{
headers.Add(exportableColumn.HeaderString);
}
Func<T, Object> func = exportableColumn.Func.Compile();
compiledFuncLookup.Add(exportableColumn.Func, func);
if (!String.IsNullOrEmpty(exportableColumn.CustomFormatString))
{
var value = func(item);
values.Add(value != null ?
String.Format(exportableColumn.CustomFormatString, value.ToString()) : "");
}
else
{
var value = func(item);
values.Add(value != null ? value.ToString() : "");
}
}
else
{
if (!String.IsNullOrEmpty(exportableColumn.CustomFormatString))
{
var value = compiledFuncLookup[exportableColumn.Func](item);
values.Add(value != null ?
String.Format(exportableColumn.CustomFormatString, value.ToString()) : "");
}
else
{
var value = compiledFuncLookup[exportableColumn.Func](item);
values.Add(value != null ? value.ToString() : "");
}
}
}
if (!doneHeaders)
{
writer.WriteLine(headers.Aggregate((start, end) => start + seperator + end));
doneHeaders = true;
}
writer.WriteLine(values.Aggregate((start, end) => start + seperator + end));
}
}
// <summary>
/// Export all specified columns as a XML string, using column data provided
/// and use custom headers depending on whether a custom header string was supplied.
/// Use custom formatted column data or default data depending on whether a custom format string was supplied.
/// </summary>
public void ToXML(XmlTextWriter writer)
{
if (columns.Count == 0)
throw new InvalidOperationException("You need to specify at least one element to export value");
foreach (T item in sourceList)
{
List<String> values = new List<String>();
foreach (ExportableColumn<T> exportableColumn in columns)
{
if (!doneHeaders)
{
if (String.IsNullOrEmpty(exportableColumn.HeaderString))
{
headers.Add(MakeXMLNameLegal(GetPropertyName(exportableColumn.Func)));
}
else
{
headers.Add(MakeXMLNameLegal(exportableColumn.HeaderString));
}
Func<T, Object> func = exportableColumn.Func.Compile();
compiledFuncLookup.Add(exportableColumn.Func, func);
if (!String.IsNullOrEmpty(exportableColumn.CustomFormatString))
{
var value = func(item);
values.Add(value != null ?
String.Format(exportableColumn.CustomFormatString, value.ToString()) : "");
}
else
{
var value = func(item);
values.Add(value != null ? value.ToString() : "");
}
}
else
{
if (!String.IsNullOrEmpty(exportableColumn.CustomFormatString))
{
var value = compiledFuncLookup[exportableColumn.Func](item);
values.Add(value != null ?
String.Format(exportableColumn.CustomFormatString, value.ToString()) : "");
}
else
{
var value = compiledFuncLookup[exportableColumn.Func](item);
values.Add(value != null ? value.ToString() : "");
}
}
}
if (!doneHeaders)
{
writer.Formatting = Formatting.Indented;
writer.WriteStartDocument(true);
writer.WriteProcessingInstruction("xml-stylesheet", "type='text/xsl' href='dump.xsl'");
writer.WriteComment("List Exporter dump");
// Write main document node and document properties
writer.WriteStartElement("dump");
writer.WriteAttributeString("date", DateTime.Now.ToString());
doneHeaders = true;
}
writer.WriteStartElement("item");
for (int i = 0; i < values.Count; i++)
{
writer.WriteStartElement(headers[i]);
writer.WriteString(values[i]);
writer.WriteEndElement();
}
writer.WriteEndElement();
}
writer.WriteEndElement();
writer.Flush();
}
/// <summary>
/// Export to file, using the AsCSVString() method to supply the exportable data
/// </summary>
public void WhichIsExportedToFileLocation(StreamWriter fileWriter)
{
AsCSVString(fileWriter);
}
/// <summary>
/// Gets a Name from an expression tree that is assumed to be a
/// MemberExpression
/// </summary>
private static string GetPropertyName<T>(
Expression<Func<T, Object>> propertyExpression)
{
var lambda = propertyExpression as LambdaExpression;
MemberExpression memberExpression;
if (lambda.Body is UnaryExpression)
{
var unaryExpression = lambda.Body as UnaryExpression;
memberExpression = unaryExpression.Operand as MemberExpression;
}
else
{
memberExpression = lambda.Body as MemberExpression;
}
var propertyInfo = memberExpression.Member as PropertyInfo;
return propertyInfo.Name;
}
private string MakeXMLNameLegal(string aString)
{
StringBuilder newName = new StringBuilder();
if (!char.IsLetter(aString[0]))
newName.Append("_");
// Must start with a letter or underscore.
for (int i = 0; i <= aString.Length - 1; i++)
{
if (char.IsLetter(aString[i]) || char.IsNumber(aString[i]))
{
newName.Append(aString[i]);
}
else
{
newName.Append("_");
}
}
return newName.ToString();
}
}
}
