Library (C# .NET) for Parsing(Reading) & Writing fixed-width/flat data files (.txt, others).
Uses FastMember instead of slower Reflection.
It is targeting NetStandard 2.0 so it can be used on project targeting NetCore(2.0+) or NetFramework(4.6.1+).
Available on latest version.
Package manager console command for installation: Install-Package FixedWidthParserWriter
There are 2 main types of usage that are explained in the following segments: 1. LineFields 2. FileFields and
3. CustomFileFields
Both are simple to use and easily configured with Attributes.
Contributing
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Please read CONTRIBUTING for details on code of conduct, and the process for submitting pull requests.
Want to Contact us for Development & Consulting: www.codis.tech
Also take a look into others packages:
-Open source (MIT or cFOSS) authored .Net libraries (@Infopedia.io personal blog post)
For parsing/writing we make a model which Properties have [FixedWidthLineField] Attribute:
public class InvoiceItem
{
[FixedWidthLineField(Start = 1, Length = 3)]
public int Number { get; set; }
[FixedWidthLineField(Start = 4, Length = 1)]
public string NumberedBullet { get; set; } = ".";
[FixedWidthLineField(Start = 5, Length = 30)]
public string Description { get; set; }
[FixedWidthLineField(Start = 35, Length = 6)]
public int Quantity { get; set; }
[FixedWidthLineField(Start = 41, Length = 13)]
public decimal Price { get; set; }
[FixedWidthLineField(Start = 54, Length = 13)]
public decimal Amount => Quantity * Price;
}
Then we can call it like this:
public List<Invoiceitem> ParseFieldsFromLines(new List<string> dataLines) // dataLines are stripped of header
{
List<InvoiceItem> invoiceItems = new FixedWidthLinesProvider<InvoiceItem>().Parse(dataLines);
return invoiceItems;
}
public List<string> WriteFieldsToLines(List<InvoiceItem> invoiceItems)
{
List<string> dataLines = new FixedWidthLinesProvider<InvoiceItem>().Write(invoiceItems);
return dataLines;
}
[FixedWidthLineField] has following parameters that can be configured for each Property:
Start - required for LineType so that order of lineFields does not depends on order of modelPropertis
Length - when writing if Property has longer value then defined in Length it will be cut from the right to fit - valueTrim
negative values means from Right side
Format - Defaults per data type or group
Pad - Defaults per data category: { PadNumeric = ' ', PadNonNumeric = ' ' }
PadSide - Defaults per data category: { PadSideNumeric = PadSide.Left, PadSideNonNumeric = PadSide.Right }
DoTrim - Default is 'True' when text will be trimmed before casting
StructureTypeId - Default = 0, used when having multiple files with different structure or format for same data
NullPattern - Default = string.Empty, Pattern used to represent a null value
_Format* types:
-FormatNumberInteger Default = "0", *groupFormat:Int32,Int64
-FormatNumberDecimal Default = "0.00", *groupFormat:Decimal,Single,Double
("0;00" - Special custom Format that removes decimal separator: 123.45 -> 12345)
-FormatBoolean . . . . . . Default = "1; ;0" ("ValueForTrue;ValueForNull;ValueForFalse")
-FormatDateTime. . . . . .Default = "yyyyMMdd"
Custom format strings for Numeric and DateTime.
Special feature is DynamicSettings with which Attributes values can be defined at runtime, for all usage types.
Data is forwarded using Dict with PropertyName and Attribute: Dictionary<string, FixedWidthAttribute> dynamicSettings.
It can be sett for all needed Properties when having no Attributes, or just add/override some specific. And if need to exclude ones that has regular Atribute then set it with Null.
Sample in Test: [InlineData(FixedWidthSettingsType.Dynamic)] public void LineParserTest(FixedWidthSettingsType settings)
When need more then 1 file structure/format we can put multiple Attributes per Property with different StructureTypeId.
Next example shows 2 structures, second has one less Property and different PadNumeric: '0' instead of ' '(space).
To change DefaultConfig per StructureType, model should implement IFixedWidth interface with SetDefaultConfig() func.
public enum ConfigType { Alpha, Beta }
public class InvoiceItem : IFixedWidth
{
public DefaultConfig GetDefaultConfig(int StructureTypeId)
{
var defaultConfig = new DefaultConfig();
switch ((ConfigType)StructureTypeId)
{
case ConfigType.Alpha:
// config remains initial default
break;
case ConfigType.Beta:
defaultConfig.PadNumeric = '0';
break;
}
return defaultConfig;
}
[FixedWidthLineField(StructureTypeId = (int)ConfigType.Alpha, Start = 1, Length = 3)]
[FixedWidthLineField(StructureTypeId = (int)ConfigType.Beta, Start = 1, Length = 4)]
public int Number { get; set; }
[FixedWidthLineField(StructureTypeId = (int)ConfigType.Alpha, Start = 4, Length = 1)]
public string NumberedBullet { get; set; } = ".";
[FixedWidthLineField(StructureTypeId = (int)ConfigType.Alpha, Start = 5, Length = 30)]
[FixedWidthLineField(StructureTypeId = (int)ConfigType.Beta, Start = 5, Length = 30)]
public string Description { get; set; }
//... Others Properties
}
Beta Structure:
No | Description | Qty | Price | Amount |
0001Laptop Dell xps13 0000010000000821.000000000821.00
0002Monitor Asus 32'' 0000020000000478.000000000956.00
Calling the methods:
List<InvoiceItem> itemsA = new FixedWidthLinesProvider<InvoiceItem>().Parse(dataLinesA, (int)ConfigType.Alpha);
List<InvoiceItem> itemsB = new FixedWidthLinesProvider<InvoiceItem>().Parse(dataLinesB, (int)ConfigType.Alpha);
PARSE method for all use cases can also optionally have third parameter List<string> errorLog which when sent as Empty list(not null) will be loaded with list of Exceptions if any were to happen during parsing and casting operations. When method is called without this param, which remains null, in that case first error with throw Exception and procedure will be stopped.
Full Examples are in Tests of the project.
2. Data in FileFields
Second usage is when one data record is in different rows at defined positions; Record per File (Fixed/Relative-Height), E.g.:
In situation where many same type properties have Format different from default one, instead of setting custom format individually for each Property, it is possible to override DefaultConfig for certain data types/groups in that class:
public class Invoice : IFixedWidth
{
public DefaultConfig GetDefaultConfig(int StructureTypeId)
{
return new DefaultConfig
{
FormatDateTime = "yyyy-MM-dd"
};
}
[FixedWidthFileField(Line = 1)]
public string CompanyName { get; set; }
// Format set on class with FormatDateTime so not required on each Attribute of DateTime Property
[FixedWidthFileField(Line = 4, Start = 15, Length = 19/*, Format = "yyyy-MM-dd"*/)]
public DateTime Date { get; set; }
/* ... Other Properties */
}
If we need to changed DefaultConfig(Format) for multiple models then we could override entire Provider to keep it DRY.
Combining both previous usages we can make complex file structures like invoiceFull.
When there is some special situation where some Fields can not be configured with existing options, then we can make additional custom parsing prior or/and after calling the method - PRE & POST Processing.
3. Data in CustomFileFields
Third use case is when one data field is relative to some text position.
SoftysTech LCC company
__________________________________________________________________
Date generated: 30.06.2020.
Q REPORT no. 11/20**
1569ccACTN.162-677-169-796
...
Revenue:
1,234.55
...
xx
public class Report
{
[CustomFileField(EndsWith = " company")]
public string CompanyName { get; set; }
[CustomFileField(StartsWith = "Date generated: ", Format = "d.M.yyyy.")]
public DateTime Date { get; set; }
[CustomFileField(Contains = "Q REPORT no. ", RemoveText = "**")]
public string Number { get; set; }
[CustomFileField(Contains = "ACTN.", Length = -15)]
public string Account { get; set; }
[CustomFileField(StartsWith = "Revenue:", Offset = 1)]
public decimal Revenue { get; set; }
}
For parsing [CustomFileField] attributes are used, with additional params:
StartsWith, EndsWith, Contains - finds lines with first occurance of search criteria
Offset - moves found line up(is positive) or down(negative value) for defined number of rows
RemoveText - to clear custom substring from text value before additional casting
RemoveStartsWith, RemoveEndsWith, RemoveContains - defaults are 'True' meaning that search string is also cleared
latest version.