I am creating a document conversion application. Ideally, you should be able to receive almost any file and reject it (it is not compatible) or return a converted version (in most cases, convert from x to PDF). It will also have some Sharepoint features such as download, upload, version control, etc., but that comes later. I wanted to create a standard form of conversion, but allow the classes to perform their own logic and specific tasks, since the conversion logic can be significantly different for different types of files. I also wanted to make sure that a Document It has a specific set of properties and methods (mainly to help with the integration of Sharepoint).
An example would be to take an existing Word document and return a PDF.
I'm not sure how to implement the part that decides what kind of conversion to use based on something like the file extension of the original document and the whole application "feels" a little bad.
I am at a stage early enough so that, if significant change is needed, it can be achieved. I think I could be confusing different design patterns and then confusing myself to make bad decisions. I have provided a simplified version of the code below, which is identical to my own code, less the things of Sharepoint and some of the properties in some of the classes (just to make reading easier).
Conversion abstract class
public abstract class Conversion
{
protected abstract IDocument Document { get; set; }
protected abstract bool SaveDocumentLocal { get; set; }
public Stream ConvertDocument()
{
BeforeConvert();
var conv = Convert();
if (SaveDocumentLocal)
{
this.SaveLocally(conv);
}
return conv;
}
protected virtual void BeforeConvert() { }
protected virtual Stream Convert() { return new MemoryStream(); }
protected virtual void SaveLocally(Stream doc) { }
}
IDocument Interface
public interface IDocument
{
string Url { get; set; }
string LocalPath { get; set; }
int MinorVersion { get; }
int MajorVersion { get; }
DateTime CreateDate { get; set; }
void SetVersion(int minor, int major);
}
Document class
public class Document : IDocument
{
public string Url { get; set; }
public string LocalPath { get; set; }
public int MinorVersion { get; private set; }
public int MajorVersion { get; private set; }
public DateTime CreateDate { get; set; }
public FileExtension Extension { get; set; }
public Document(string url)
{
Url = url;
CreateAndSetLocalPath();
SetFileName();
Extension = SetFileExtension();
SetVersion(2,0);
}
private FileExtension SetFileExtension() { return new FileExtension(); }
private void SetFileName() { Console.WriteLine("Set the filename"); }
private void CreateAndSetLocalPath() { Console.WriteLine("Created and set local path"); }
public void SetVersion(int major, int minor) { Console.WriteLine("Version set to {0}.{1}", major, minor); }
}
WordDocumentConverter class
public class WordDocumentConverter : Conversion
{
public WordDocumentConverter(IDocument doc)
{
Document = doc;
//Construct object
}
protected override IDocument Document { get; set; }
protected override bool SaveDocumentLocal { get; set; }
protected override void BeforeConvert()
{
//Do stuff before converting
}
protected override Stream Convert()
{
//Specific Word document conversion logic here to convert the IDocument to something else
Console.WriteLine("Converted from Word to PDF");
return new MemoryStream();
}
protected override void SaveLocally(Stream doc)
{
//Specific save logic here...
Console.WriteLine("Saved a copy of 'doc' locally");
}
}
Sample Call Code
var doc = new Document(@"C:tempdoc1.docx");
var wdc = new WordDocumentConverter(doc);
wdc.ConvertDocument();
Let me know if I am missing something or I have not explained myself well. Thank you.
