/// <summary>
/// Converts the specified value to the given string format as per the property conversion rules.
/// Multiple values are each converted to the edit string format and combined into a delimited string.
/// </summary>
/// <param name="value">The value to convert.</param>
/// <param name="format">The string format to use.</param>
/// <returns>A string that represents the given value(s) in the given format.</returns>
public string ValueToString(object value, ValueFormat format)
{
object cVal = ResolveValue(value, format);
IList lst = cVal as IList;
return(lst != null?ListToString(lst, format) : Convert.ToString(cVal));
}
/// <summary>
/// Resolves the given value or a list of values to the specified format based on the current property configuration.
/// If the property is restricted or the value is null and the format is string based,
/// the <c> RestrictedString</c> or <c>NullString</c> are returned respectively.
/// If the property is multivalued it will try to convert the value to a list or parse it into a list if it's a string
/// or just add it to a new list as is and then convert each value in the list into the given format.
/// Otherwise it will try to convert the single value to the given format.
/// If a custom value converter is set on the property, it will be used first before the default property conversion rules are applied.
/// </summary>
/// <param name="value">The value or list of values to resolve to the given format.</param>
/// <param name="format">The format to convert the value to.</param>
/// <returns>A value or a list of values resolved to the given format based on the property configuration.</returns>
public object ResolveValue(object value, ValueFormat format)
{
if (IsRestricted())
{
return(format.IsString() ? RestrictedString : value);
}
if (IsValueNull(value, format))
{
return(format.IsString() ? NullString : null);
}
if (IsMultiValued)
{
IList lst = new List <object>();
if (value is IList)
{
lst = (IList)value;
}
else if (value is string)
{
string[] vals = ((string)value).Split(
ParseListSeparators, StringSplitOptions.None);
foreach (string val in vals)
{
if (!IsValueNull(val, format))
{
lst.Add(val);
}
}
}
else
{
lst.Add(value);
}
IList resLst = CreateList(format);
foreach (object val in lst)
{
object cval = val;
if (ValueConverter == null || !ValueConverter(ref cval, format))
{
cval = ConvertValue(cval, format);
}
if (!IsValueNull(cval, format))
{
resLst.Add(cval);
}
}
return(resLst);
}
else
{
object cval = value;
if (ValueConverter == null || !ValueConverter(ref cval, format))
{
cval = ConvertValue(cval, format);
}
return(cval);
}
}
/// <summary>
/// Creates a new list for the given format.
/// Overrides the default behavior to return a typed generic list for the Transport format.
/// </summary>
/// <param name="format">The format to create a new list for.</param>
/// <returns>A new list for the given format.</returns>
protected override IList CreateList(ValueFormat format)
{
// we don't have to store values in a typed list if the format is internal,
// since some values may be still invalid. However, the values should be validated
// before they are transfered over the network, so the transport format requires a typed list.
return(format == ValueFormat.Transport ? new List <T>() : base.CreateList(format));
}
/// <summary>
/// Converts a list of values to a string for the given format.
/// Default implementation uses the DisplayListSeparator to concatenate the values for any format.
/// Subclasses can override this behavior to differentiate between the <c>DisplayString</c> format
/// and the <c>EditString</c> format and can also provide custom delimiting, e.g. comma-separated
/// and a new line between every five values to get five comma-separated values per line.
/// </summary>
/// <param name="list">The list of values to convert to string.</param>
/// <param name="format">The string format for which the conversion is required.</param>
/// <returns>The string representation of the given list.</returns>
public virtual string ListToString(IList list, ValueFormat format)
{
string res = "";
foreach (object val in list)
{
res += (res == "" ? "" : displayListSeparator) + Convert.ToString(val);
}
return(res);
}
/// <summary>
/// A filtering function that determines if the value of the specified property in the given row
/// matches the specified criteria value using supplied operator.
/// </summary>
/// <param name="property">The data property of the object to match.</param>
/// <param name="row">The data row to get the value from.</param>
/// <param name="oper">Comparison operator to use.</param>
/// <param name="criteria">The value to compare to.</param>
/// <param name="caseSensitive">True to perform case-sensitive string matching, false otherwise.</param>
/// <returns>True if the property value in the given row matches the specified criteria, false otherwise.</returns>
public virtual bool PropertyValueMatches(DataProperty property, DataRow row, Operator oper, object criteria, bool caseSensitive)
{
ValueFormat format = criteria?.GetType() == typeof(string) ? ValueFormat.DisplayString : ValueFormat.Internal;
object value = property.GetValue(format, row);
criteria = property.ResolveValue(criteria, format);
if (format.IsString() && !caseSensitive)
{
value = value?.ToString()?.ToLower();
criteria = criteria?.ToString()?.ToLower();
}
return(oper.Matches(value, criteria));
}
/// <summary>
/// Gets a value of the specified property from the given data row.
/// </summary>
/// <param name="dataItem">data row to get the data from.</param>
/// <param name="property">proprety name to retrieve.</param>
/// <param name="format">value format to return.</param>
/// <returns></returns>
public static object Get(object dataItem, string property, ValueFormat format)
{
DataRow dr = dataItem as DataRow;
if (dr == null)
{
return(null);
}
DataProperty dp = dr.List[property];
if (dp == null || dp.Column < 0 || dp.Column >= dr.Count)
{
return(null);
}
return(dp.ResolveValue(dr[dp.Column], format));
}
/// <summary>
/// A function to determine if the given value is considered to be null for the given format.
/// Default implementation returns true if the value is null, is an empty list,
/// is a string with blank spaces only or is equal to the NullString for any format.
/// Subclasses can override this function to differentiate by the value format
/// or to provide different or additional rules.
/// </summary>
/// <param name="value">The value to check for null.</param>
/// <param name="format">The value format, for which the null check is performed.</param>
/// <returns>True if the value is considered to be null for the given format, otherwise false.</returns>
public virtual bool IsValueNull(object value, ValueFormat format)
{
if (value == null)
{
return(true);
}
IList lst = value as IList;
if (lst != null && lst.Count == 0)
{
return(true);
}
if (value is string)
{
string str = ((string)value).Trim();
return(string.IsNullOrEmpty(str) || str == NullString);
}
return(false); // non-null non-string
}
/// <summary>
/// Sets the value format dependency property on a text block.
/// </summary>
/// <param name="obj">The text block element to set the property on.</param>
/// <param name="value">The value format to set on the text block.</param>
public static void SetValueFormat(TextBlock obj, ValueFormat value)
{
obj.SetValue(ValueFormatProperty, value);
}
/// <summary>
/// Gets the value of the current property in the specified format,
/// using the provided data row as the data source, if applicable.
/// If no row is specified, then returns the value of the property itself.
/// </summary>
/// <param name="format">The format to return the value in.</param>
/// <param name="row">The data row to use as a source.</param>
/// <returns></returns>
public object GetValue(ValueFormat format, DataRow row = null)
{
object val = Column < 0 ? InternalValue : row == null || row.List != parent ? null : row[Column];
return(format.IsString() ? ValueToString(val, format) : ResolveValue(val, format));
}
/// <summary>
/// Converts a list of values to a string for the given format.
/// Default implementation uses the DisplayListSeparator to concatenate the values for any format.
/// Subclasses can override this behavior to differentiate between the <c>DisplayString</c> format
/// and the <c>EditString</c> format and can also provide custom delimiting, e.g. comma-separated
/// and a new line between every five values to get five comma-separated values per line.
/// </summary>
/// <param name="list">The list of values to convert to string.</param>
/// <param name="format">The string format for which the conversion is required.</param>
/// <returns>The string representation of the given list.</returns>
public virtual string ListToString(IList list, ValueFormat format)
{
string res = "";
foreach (object val in list)
res += (res == "" ? "" : displayListSeparator) + Convert.ToString(val);
return res;
}
/// <summary>
/// A function to determine if the given value is considered to be null for the given format.
/// Default implementation returns true if the value is null, is an empty list,
/// is a string with blank spaces only or is equal to the NullString for any format.
/// Subclasses can override this function to differentiate by the value format
/// or to provide different or additional rules.
/// </summary>
/// <param name="value">The value to check for null.</param>
/// <param name="format">The value format, for which the null check is performed.</param>
/// <returns>True if the value is considered to be null for the given format, otherwise false.</returns>
public virtual bool IsValueNull(object value, ValueFormat format)
{
if (value == null) return true;
IList lst = value as IList;
if (lst != null && lst.Count == 0) return true;
string str = value.ToString().Trim();
return string.IsNullOrEmpty(str) || str == NullString;
}
/// <summary>
/// Sets the value format dependency property on a text block.
/// </summary>
/// <param name="obj">The text block element to set the property on.</param>
/// <param name="value">The value format to set on the text block.</param>
public static void SetValueFormat(TextBlock obj, ValueFormat value)
{
obj.SetValue(ValueFormatProperty, value);
}
/// <summary>
/// Gets a value of the specified property from the given data row.
/// </summary>
/// <param name="dataItem">data row to get the data from.</param>
/// <param name="property">property name to retrieve.</param>
/// <param name="format">value format to return.</param>
/// <returns></returns>
public static object Get(object dataItem, string property, ValueFormat format)
{
var dr = dataItem as DataRow;
return(dr?.List[property]?.GetValue(format, dr));
}
/// <summary>
/// Creates a new list for the given format. The default implementation just returns a new untyped ArrayList.
/// Subclasses can override it to return typed generic lists for the Transport format.
/// </summary>
/// <param name="format">The format to create a new list for.</param>
/// <returns>A new list for the given format.</returns>
protected virtual IList CreateList(ValueFormat format)
{
return(new List <object>());
}
/// <summary>
/// Converts a single value to a given format. The default implementation does nothing to the value,
/// but subclasses can implement the property specific rules for each format.
/// </summary>
/// <param name="value">A single value to convert to the given format.</param>
/// <param name="format">The value format to convert the value to.</param>
/// <returns>The value converted to the given format.</returns>
protected virtual object ConvertValue(object value, ValueFormat format)
{
return(value);
}
/// <summary>
/// Resolves the given value or a list of values to the specified format based on the current property configuration.
/// If the property is restricted or the value is null and the format is string based,
/// the <c> RestrictedString</c> or <c>NullString</c> are returned respectively.
/// If the property is multivalued it will try to convert the value to a list or parse it into a list if it's a string
/// or just add it to a new list as is and then convert each value in the list into the given format.
/// Otherwise it will try to convert the single value to the given format.
/// If a custom value converter is set on the property, it will be used first before the default property conversion rules are applied.
/// </summary>
/// <param name="value">The value or list of values to resolve to the given format.</param>
/// <param name="format">The format to convert the value to.</param>
/// <returns>A value or a list of values resolved to the given format based on the property configuration.</returns>
public object ResolveValue(object value, ValueFormat format)
{
if (IsRestricted())
return format.IsString() ? RestrictedString : value;
if (IsValueNull(value, format))
return format.IsString() ? NullString : null;
if (IsMultiValued)
{
IList lst = new List<object>();
if (value is IList) lst = (IList)value;
else if (value is string)
{
string[] vals = ((string)value).Split(
ParseListSeparators, StringSplitOptions.None);
foreach (string val in vals)
if (!IsValueNull(val, format)) lst.Add(val);
}
else lst.Add(value);
IList resLst = CreateList(format);
foreach (object val in lst)
{
object cval = val;
if (ValueConverter == null || !ValueConverter(ref cval, format))
cval = ConvertValue(cval, format);
if (!IsValueNull(cval, format)) resLst.Add(cval);
}
return resLst;
}
else
{
object cval = value;
if (ValueConverter == null || !ValueConverter(ref cval, format))
cval = ConvertValue(cval, format);
return cval;
}
}
/// <summary> /// Gets a string value of the current property in the specified string format, /// using the provided data row as the data source, if applicable. /// If no row is specified, then returns the value of the property itself. /// </summary> /// <param name="format">The string format to return the value in.</param> /// <param name="row">The data row to use as a source.</param> /// <returns></returns> public string GetStringValue(ValueFormat format, DataRow row = null) => GetValue(format, row)?.ToString();
/// <summary>
/// Converts the specified value to the given string format as per the property conversion rules.
/// Multiple values are each converted to the edit string format and combined into a delimited string.
/// </summary>
/// <param name="value">The value to convert.</param>
/// <param name="format">The string format to use.</param>
/// <returns>A string that represents the given value(s) in the given format.</returns>
public string ValueToString(object value, ValueFormat format)
{
object cVal = ResolveValue(value, format);
IList lst = cVal as IList;
return lst != null ? ListToString(lst, format) : Convert.ToString(cVal);
}
/// <summary>
/// Converts a single value to a given format. The default implementation does nothing to the value,
/// but subclasses can implement the property specific rules for each format.
/// </summary>
/// <param name="value">A single value to convert to the given format.</param>
/// <param name="format">The value format to convert the value to.</param>
/// <returns>The value converted to the given format.</returns>
protected virtual object ConvertValue(object value, ValueFormat format)
{
return value;
}
/// <summary>
/// Creates a new list for the given format. The default implementation just returns a new untyped ArrayList.
/// Subclasses can override it to return typed generic lists for the Transport format.
/// </summary>
/// <param name="format">The format to create a new list for.</param>
/// <returns>A new list for the given format.</returns>
protected virtual IList CreateList(ValueFormat format)
{
return new List<object>();
}
