I'm trying to map CSV file into class object with C#. My problem is that i have 3 different files, but I want to fallow DRY principles. Can someone tell me how to change 'ParseLine' method to make it possible?
C# consol app.
This is how my FileReader looks like:
public class FileReader<T> : IFileReader<T> where T : Entity
{
private readonly ITransactionReader<T> _transactionReader;
public FileReader(ITransactionReader<T> transactionReader)
{
_transactionReader = transactionReader;
}
public List<T> GetInfoFromFile(string filePath)
{
var lines = File.ReadAllLines(filePath);
var genericLines = new List<T>();
foreach (var line in lines)
{
genericLines.Add(_transactionReader.ParseLine(line));
}
return genericLines;
}
}
public interface IFileReader<T> where T : Entity
{
List<T> GetInfoFromFile(string filePath);
}
This is how the object should look like.
public class TransactionReader : ITransactionReader<Transaction>
{
public Transaction ParseLine(string line)
{
var fields = line.Split(";");
var transaction = new Transaction()
{
Id = fields[0],
Month = int.Parse(fields[1]),
Day = int.Parse(fields[2]),
Year = int.Parse(fields[3]),
IncomeSpecification = fields[4],
TransactionAmount = int.Parse(fields[5])
};
return transaction;
}
}
public interface ITransactionReader<T>
{
T ParseLine(string line);
}
This is how I run it for test purposes.
class Program
{
private static readonly string filePath = "C:/Users/<my_name>/Desktop/C# Practice/ERP/ERP/CsvFiles/Transaction.csv";
static void Main(string[] args)
{
ITransactionReader<Transaction> transactionReader = new TransactionReader();
IFileReader<Transaction> fileReader = new FileReader<Transaction>(transactionReader);
List<Transaction> Test()
{
var obj = fileReader.GetInfoFromFile(filePath);
return obj;
}
var list = Test();
}
}
I'm looking to modify that line:
genericLines.Add(_transactionReader.ParseLine(line));
and method arguments to make it open for any CSV fil.
I don't mind to change that composition into something more effective.
I am currently developing a software that will be used by users that should not be able to access the back-end of it all but should still be able to easily change configuration/settings for the application.
I decided the best approach would be a custom "configuration file (.cfg)" located in the root of the final build.
Simple example of the .cfg file:
serveraddress='10.10.10.10'
serverport='1234'
servertimeout='15000'
Since I wanted the configuration file to easily be extended I decided to use some custom attributes and some simple LINQ.
This does work like I expect it to, but since I am still a novice in .net I am afraid I have not gone with the best approach and my question is therefor:
Is there anything I can do to improve this?
Or is there just generally a better approach for this?
This is my code for reading the configuration file and assigning the values to it's corresponding properties.
ConfigFileHandler.cs
public void ReadConfigFile()
{
var cfgFile = new ConfigFile();
var configLines = File.ReadAllLines("configfile.cfg");
var testList = configLines.Select(line => line.Split('='))
.Select(splitString => new Tuple<string, string>(splitString[0], splitString[1].Replace("'", "")))
.ToList();
foreach (var prop in typeof(ConfigFile).GetProperties())
{
var attrs = (ConfigFileFieldAttribute[])prop.GetCustomAttributes
(typeof(ConfigFileFieldAttribute), false);
foreach (var t in from attr in attrs from t in testList where t.Item1 == attr.Name select t)
{
prop.SetValue(cfgFile, t.Item2);
}
}
}
ConfigFile.cs
class ConfigFile
{
private static string _serverAddress;
private static int _serverPort;
private static int _serverTimeout;
[ConfigFileField(#"serveraddress")]
public string ServerAddress
{
get { return _serverAddress; }
set { _serverAddress= value; }
}
[ConfigFileField(#"serverport")]
public string ServerPort
{
get { return _serverPort.ToString(); }
set { _serverPort= int.Parse(value); }
}
[ConfigFileField(#"servertimeout")]
public string ServerTimeout
{
get { return _serverTimeout.ToString(); }
set { _serverTimeout= int.Parse(value); }
}
}
any tips on writing better looking code would be highly appreciated!
UPDATE:
Thanks for all the feedback.
Below is the final classes!
https://dotnetfiddle.net/bPMnJA for a live example
Please note, this is C# 6.0
ConfigFileHandler.cs
public class ConfigFileHandler
{
public void ReadConfigFile()
{
var configLines = File.ReadAllLines("configfile.cfg");
var configDictionary = configLines.Select(line => line.Split('='))
.Select(splitString => new Tuple<string, string>(splitString[0], splitString[1].Replace("'", "")))
.ToDictionary(kvp => kvp.Item1, kvp => kvp.Item2);
ConfigFile.SetDictionary(configDictionary);
}
}
ConfigFile.cs
public class ConfigFile
{
private static Dictionary<string, string> _configDictionary;
public string ServerAddress => PullValueFromConfig<string>("serveraddress", "10.1.1.10");
public int ServerPort => PullValueFromConfig<int>("serverport", "3306");
public long ServerTimeout => PullValueFromConfig<long>("servertimeout", "");
private static T PullValueFromConfig<T>(string key, string defaultValue)
{
string value;
if (_configDictionary.TryGetValue(key, out value) && value.Length > 0)
return (T) Convert.ChangeType(value, typeof (T));
return (T) Convert.ChangeType(defaultValue, typeof (T));
}
public static void SetDictionary(Dictionary<string, string> configValues)
{
_configDictionary = configValues;
}
}
You could keep the simplicity of your config file and get rid of the nested loops by loading the values into a dictionary and then passing that into your ConfigFile class.
public static void ReadConfigFile()
{
var configLines = File.ReadAllLines("configfile.cfg");
var testList = configLines.Select(line => line.Split('='))
.Select(splitString => new Tuple<string, string>(splitString[0], splitString[1].Replace("'", "")))
.ToDictionary(kvp => kvp.Item1, kvp => kvp.Item2);
var cfgFile = new ConfigFile(testList);
}
The new ConfigFile class:
class ConfigFile
{
private Dictionary<string, string> _configDictionary;
public ConfigFile(Dictionary<string, string> configValues)
{
_configDictionary = configValues;
}
public string ServerAddress
{
get { return PullValueFromConfig("serveraddress", "192.168.1.1"); }
}
public string ServerPort
{
get { return PullValueFromConfig("serverport", "80"); }
}
public string ServerTimeout
{
get { return PullValueFromConfig("servertimeout", "900"); }
}
private string PullValueFromConfig(string key, string defaultValue)
{
string value;
if (_configDictionary.TryGetValue(key, out value))
return value;
return defaultValue;
}
}
I decided to use a custom "configuration file (.cfg)" located in the root of the final build.
Good idea. For cleaner code, you could use JSON and JSON.NET for de/serialization and put the read/write into the ConfigFile class. Here is an example that is live as a fiddle.
The ConfigFile class is responsible for loading and saving itself and uses JSON.NET for de/serialization.
public class ConfigFile
{
private readonly static string path = "somePath.json";
public string ServerAddress { get; set; }
public string ServerPort { get; set; }
public string ServerTimeout { get; set; }
public void Save()
{
var json = JsonConvert.SerializeObject(this, Formatting.Indented);
File.WriteAllText(path, json)
}
public static ConfigFile Load()
{
var json = File.ReadAllText(path);
return JsonConvert.DeserializeObject<ConfigFile>(json);
}
}
Here is how you would use it to load the file, change its properties, and save.
ConfigFile f = ConfigFile.Load();
f.ServerAddress = "0.0.0.0";
f.ServerPort = "8080";
f.ServerTimeout = "400";
f.Save();
We use the .json file extension as a convention. You could still use .cfg because it's just plain text with a specific syntax. The resultant config file content from the above usage is this:
{
"ServerAddress":"0.0.0.0",
"ServerPort":"8080",
"ServerTimeout":"400"
}
You could just tell your clients to "change the numbers only". Your approach is fine, as far as I'm concerned. The above is just a cleaner implementation.
Firstly, I would do what Phil did, and store your testlist in a Dictionary.
var configLines = File.ReadAllLines("configfile.cfg");
var testDict = configLines.Select(line => line.Split('=', 2))
.ToDictionary(s => s[0], s => s[1].Replace("'", ""));
Then you can clean up the property assignment LINQ a bit:
foreach (var prop in typeof(ConfigFile).GetProperties())
{
var attr = prop.GetCustomAttributes(false)
.OfType<ConfigFileFieldAttribute>()
.FirstOrDefault();
string val;
if (attr != null && testDict.TryGetValue(attr.Name, out val))
prop.SetValue(cfgFile, val);
}
You might even be able to call:
var attr = prop.GetCustomAttributes<ConfigFileFieldAttribute>(false).FirstOrDefault();
Don't have an IDE on me so I can't check right now
Why do have this error on this part of the code ?
this part
var data = serializer.Deserialize<EmailTemplate>(httpRequest.Form["data"].ToString());
my procedure
public int UpdateEmailTemplate()
{
HttpResponseMessage result = null;
ObjectService uploadFile = new ObjectService();
List<ActiveUp.Net.Mail.Attachment> attachment = new List<ActiveUp.Net.Mail.Attachment>();
var httpRequest = HttpContext.Current.Request;
if (httpRequest.Form["data"] != null)
{
var serializer = new JavaScriptSerializer();
var data = serializer.Deserialize<EmailTemplate>(httpRequest.Form["data"].ToString());
if (httpRequest.Files.Count > 0)
{
var docfiles = new List<string>();
foreach (string file in httpRequest.Files)
{
MemoryStream target = new MemoryStream();
httpRequest.Files[file].InputStream.CopyTo(target);
uploadFile.AddObject(data.Id, "SU_ENTITY_MSG_TEMPLATE","", target.GetBuffer(), httpRequest.Files[file].FileName);
}
}
AdminService List = new AdminService();
return List.UpdateEmailTemplate(data);
}
MY class
public class EmailTemplate
{
public int Id;
public string TypeObject;
public int? idObject;
public string ObjectName;
public string IdTeam;
public string IdTask;
public string Team;
public string task;
public string Title;
public string Subject;
public string dataHtml;
public List<Objects> fileListRequest;
}
It's pretty plainly saying that the contents of:
httpRequest.Form["data"]
...is an array of some sort. Adding .ToString() will just return it's type name. Passing that to Deserialize is what's giving you the error, as Deserialize is expecting an array and just getting a string.
Try taling the .ToString() off - this may not work. If it doesn't you'll have to convert httpRequest.Form["data"] to what ever data type you've put into it (whuich you do not say).
I have a class which models the format of the CSV being uploaded (I'm using the FileHelpers library):
[DelimitedRecord(",")]
public class CSVModel
{
[FieldQuoted('"', QuoteMode.OptionalForBoth, MultilineMode.NotAllow)]
public string Field1;
[FieldQuoted('"', QuoteMode.OptionalForBoth, MultilineMode.NotAllow)]
public string Field2;
}
Then I have a class to display the result of the upload after I've parsed the file row-by-row:
public class UploadResult
{
public List<CSVModel> InvalidField;
public List<CSVModel> Valid;
}
I won't go into detail about how I implement FileHelpers because it all works - a file can be uploaded successfully - it only breaks when I try add an instance of the CSV model to a list like so:
public static UploadResult ProcessCSV(CSVModel[] records)
{
UploadResult uploadResult = new UploadResult();
for (int i = 1; i < records.Length; i++)
{
CSVModel csvModel = records[i];
// check stuff
uploadResult.Valid.Add(csvModel); // this is where it breaks
}
return uploadResult;
}
The exception is giving me nothing more than null reference. What could I be doing incorrectly?
edit: When I debug, 'csvModel' is definitely not null when I try add it to the List
Valid is null, you have to initialize it:
public class UploadResult
{
public List<CSVModel> InvalidField = new List<CSVModel>();
public List<CSVModel> Valid = new List<CSVModel>();
}
or via constructor:
public class UploadResult
{
public UploadResult()
{
InvalidField = new List<CSVModel>();
Valid = new List<CSVModel>();
}
public List<CSVModel> InvalidField;
public List<CSVModel> Valid;
}
You are initializing UploadResult but not the List properties. Try something like this:
UploadResult uploadResult = new UploadResult {
InvalidField = new List<CSVModel>(),
Valid = new List<CSVModel>()
};
I have written an Interface for writing a very very simple Plugin. In fact it is just a class that is loaded at runtime out of a dll file and is stored as Property in another class. That class that stores the interface has to get serialized. As example this is my serialized object:
<?xml version="1.0" encoding="utf-8"?><MD5HashMapper xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.namespace.net" />
But now If i want to load that Object I get an Exception:
As example :
{"<MD5HashMapper xmlns='http://www.vrz.net/Vrz.Map'> was not expected."}
So does anyone has an idea how to solve that problem?
Code:
I have an Interface named IMap that is shared in a dll file to create Addins based on that interface:
public interface IMap
{
object Map(object input);
}
I also have different Mappers (you can pass an input through them and they modify the output). All Mappers are derived from:
[XmlInclude(typeof(ConstMapper))]
[XmlInclude(typeof(FuncMapper))]
[XmlInclude(typeof(IdentMapper))]
[XmlInclude(typeof(NullMapper))]
[XmlInclude(typeof(RefMapper))]
[XmlInclude(typeof(VarMapper))]
[XmlInclude(typeof(TableMapper))]
[XmlInclude(typeof(AddinMapper))]
public class MapperBase:ComponentBase,IMap
{ public virtual object Map(object input) {
throw new NotImplementedException("Diese Methode muss überschrieben werden");
}
public override string ToString() {
return ShortDisplayName;
}
}
Just forget ComponentBase. It is not important for this...
Now i also have a AddinMapper. The main function of that mapper is to cast create MapperBase Object out of the IMap object:
And that is exactly that class I want to seralize including the properties of the Mapper Property (type IMap).
public class AddinMapper : MapperBase
{
private static MapperBase[] _mappers;
const string addinDirectory = #"Addin\Mappers\";
//Mappers from *.dll files are loaded here:
[XmlIgnore]
public static MapperBase[] Mappers
{
get
{
if (_mappers == null)
{
List<MapperBase> maps = new List<MapperBase>();
foreach (string dll in Directory.GetFiles(addinDirectory, "*.dll"))
{
if (Path.GetFileName(dll) != "IMap.dll")
{
var absolutePath = Path.Combine(Environment.CurrentDirectory, dll);
Assembly asm = Assembly.LoadFile(absolutePath);
foreach (Type type in asm.GetTypes().ToList().Where(p => p.GetInterface("IMap") != null))
{
maps.Add(new AddinMapper((IMap)Activator.CreateInstance(type)));
}
}
}
Mappers = maps.ToArray();
}
return _mappers;
}
set
{
_mappers = value;
}
}
IMap _base;
public string MapperString { get; set; }
[XmlIgnore()]
public IMap Mapper
{
get
{
if (_base == null)
{
Type type = null;
foreach (MapperBase mapperBase in Mappers)
{
if (mapperBase is AddinMapper && ((AddinMapper)mapperBase).Mapper.GetType().FullName == _mapperName)
{
type = (mapperBase as AddinMapper).Mapper.GetType();
break;
}
}
if (type != null)
{
XmlSerializer serializer = new XmlSerializer(type);
using (StringReader reader = new StringReader(MapperString))
{
Mapper = (IMap)serializer.Deserialize(reader);
}
}
}
return _base;
}
private set
{
_base = value;
StoreMapperString();
}
}
string _mapperName;
[System.ComponentModel.Browsable(false)]
public string MapperName
{
get
{
return _mapperName;
}
set
{
_mapperName = value;
}
}
public AddinMapper(IMap baseInterface) : this()
{
Mapper = baseInterface;
_mapperName = baseInterface.GetType().FullName;
}
public AddinMapper()
{
}
public override object Map(object input)
{
return Mapper.Map(input);
}
public override string ToString()
{
return Mapper.ToString();
}
private void StoreMapperString()
{
MemoryStream memstream = new MemoryStream();
XmlStore.SaveObject(memstream, Mapper);
using (StreamReader reader = new StreamReader(memstream))
{
memstream.Position = 0;
MapperString = reader.ReadToEnd();
}
}
}
An example for such a addin would be:
public class ReplaceMapper : IMap
{
public string StringToReplace { get; set; }
public string StringToInsert { get; set; }
public object Map(object input)
{
if (input is string)
{
input = (input as string).Replace(StringToReplace, StringToInsert);
}
return input;
}
}
And the Problem is I want to save the Settings like StringToReplace,... as xml
I ve solved my problem:
I really don t know why but take a look at this article: http://www.calvinirwin.net/2011/02/10/xmlserialization-deserialize-causes-xmlns-was-not-expected/
(if link is dead later)
XmlRootAttribute xRoot = new XmlRootAttribute();
xRoot.ElementName = elementName;
xRoot.IsNullable = true;
XmlSerializer ser = new XmlSerializer(typeof(MyObject), xRoot);
XmlReader xRdr = XmlReader.Create(new StringReader(xmlData));
MyObject tvd = (MyObject)ser.Deserialize(xRdr);
Now the important thing: It does not matter if you don t get an excption on serialization. You have to add the XmlRootAttribute on both ways: Serialisation and Deserialization.