API for file management

PDF
Medium

Creatio core provides a set of file management classes and interfaces in version 7.17.2 and up:

  • Terrasoft.File.Abstractions namespace – interfaces and abstract classes that specify the file management logic in Creatio.
  • Terrasoft.File namespace – concrete implementations of the abstractions used in Creatio.

The location of a file and file locators 

The location of a file is specified using a file locator, which is an object that implements the Terrasoft.File.Abstractions.IFileLocator interface.

A file locator must contain a unique file identifier: RecordId.

You can create different file locator implementations for different file storages. Depending on the file storage mechanics, the file locator may have extra properties for the identification of the file location. For example, the Terrasoft.File.EntityFileLocator class is an implementation of the file locator for the current [Attachments] file storage in Creatio. An EntityFileLocator object has the base RecordId property and an EntitySchemaName property: the name of the object schema where the file is stored, for example: "ActivityFile" or "CaseFile".

All file management methods employ file locators.

Files and file storages 

File structure in Creatio:

  • file metadata
  • file content.

Metadata describe the file properties:

  • name
  • size in bytes
  • creation date, etc.

File metadata are based on the Terrasoft.File.Abstractions.Metadata.FileMetadata abstract class. Let’s consider the Terrasoft.File.Metadata.EntityFileMetadata class as its concrete implementation. This class describes the metadata of the [Attachments] object files.

“Content” is the contents of the file. 

In Creatio, the file metadata and content are stored in different storages.

  • The file metadata storage must implement the Terrasoft.File.Abstractions.Metadata.IFileMetadataStorage interface.
  • The file content storage must implement the Terrasoft.File.Abstractions.Metadata.IFileContentStorage interface.

Specific implementations of these interfaces cover all subtle aspects of interaction with different file storage systems: Creatio [Attachments], the filesystem of the server, Amazon S3. Google Drive, etc.

The Terrasoft.File.Abstractions.IFile interface provides essential file management methods applicable in any file storage. In terms of Creatio, a file is an implementation of this interface. The methods of this interface are used for asynchronous file management. Synchronous file management methods are available in the Terrasoft.File.Abstractions.FileUtils derived class.

Get a file (IFileFactory) 

The Terrasoft.File.Abstractions.IFileFactory interface provides methods for creating and getting objects of a class that implements the Terrasoft.File.Abstractions.IFile interface. This interface is implemented by a factory accessed using the methods of the Terrasoft.File.FileFactoryUtils class that extends the UserConnection class. Therefore, an instance of UserConnection or SystemUserConnection is required for file management.

The location of a new or existing file is unambiguously determined by its file locator. To access an existing file, its RecordId identifier is required. For a new file, create an identifier and pass it to the locator creation method.

Implement and register a new file storage type 

To implement a new file storage type:

  1. Create an implementation of the Terrasoft.File.Abstractions.Content.IFileContentStorage interface that describes the API required for working with the file storage.
  2. If the current file metadata storage (Terrasoft.File.Metadata.EntityFileMetadataStorage) is not sufficient for your tasks, implement your own metadata storage, metadata type, and file locator type:
    • The file metadata storage must implement the Terrasoft.File.Abstractions.Metadata.IFileMetadataStorage interface.
    • The file locator must implement the Terrasoft.File.Abstractions.IFileLocator interface.
    • The metadata class must inherit from the Terrasoft.File.Abstractions.Metadata.FileMetadata class.
  3. The new file content storage and file metadata storage must be registered in the corresponding “SysFileContentStorage” and “SysFileMetadataStorage” lookups.

File management exceptions 

Exception type

Message

Exception conditions

Terrasoft.File.Abstractions.
FileNotFoundByLocatorException

File not found by locator '{locator_type}{locator.ToString}’

When accessing any properties or methods of the IFile interface if the file metadata are not found.

System.InvalidOperationException Can't delete new file: '{locator_type}{locator.ToString}' When attempting to delete a newly created file: FileMetadata.StoringState == FileStoringState.New
Terrasoft.Common.NullOrEmptyException File name cannot be null or empty When attempting to save a file with the Name field left blank
System.InvalidOperationException Can't find a metadata storage for the '{locator_type}' locator type

If a file metadata storage compatible by the locator type is not found.

System.InvalidOperationException Can't find a content storage for the '{metadata_type}' metadata type If a file content storage compatible by the metadata type is not found.
File management examples
Medium

Example. Get an instance of a class that implements the IFile interface.

/* Get the file factory. */
IFileFactory fileFactory = UserConnection.GetFileFactory();
/* Creating a file locator for a file identified by the recordId and stored in the "ActivityFile" DB table ("Attachments" for the "Activity" object). */
var fileLocator = new EntityFileLocator("ActivityFile", recordId);
/* Pass the created locator to the Get method of the factory. */
IFile file = fileFactory.Get(fileLocator);
/* This will return an instance of a class that implements the IFile interface. Use it to manupulate the file and its contents. */
/* Create a file locator for a file identified by the recordId and stored in the "ActivityFile" DB table ("Attachments" for the "Activity" object). */
var fileLocator = new EntityFileLocator("ActivityFile", recordId);
/* Pass the created locator to the GetFile extending method. */
IFile file = UserConnection.GetFile(fileLocator);
/* This will return  an instance of a class that implements the IFile interface. Use it to manipulate the file and its contents. */
/* Get the file factory. */
IFileFactory fileFactory = UserConnection.GetFileFactory(); 
/* Creating a unique identifier for the new file. */
Guid recordId = Guid.NewGuid();
/* Create a file locator for a new file identified by the recordId and stored in the "ActivityFile" DB table ("Attachments" for the "Activity" object). */
var fileLocator = new EntityFileLocator("ActivityFile", recordId);
/* Pass the created locator to the Create method of the factory. */
IFile file = fileFactory.Create(fileLocator);
/* This will return an instance of a class that implements the IFile interface. Use it to manipulate the file and its contents. */
/* Create a unique ID for the new file. */
Guid recordId = Guid.NewGuid(); 
/* Create a file locator for a new file identified by the recordId and stored in the "ActivityFile"  DB table ("Attachments" for the "Activity" object). */
var fileLocator = new EntityFileLocator("ActivityFile", recordId); 
/* Pass the created locator to the CreateFile extension method. */ 
IFile file = UserConnection.CreateFile(fileLocator); 
/* This will return an instance of a class that implements the IFile interface. Use it to manipulate the file and its contents. */

Example. Create a new file bound to an Activities(Activities) record.

Creating a new file
/* Create a unique ID for the new file. */
Guid fileId = Guid.NewGuid(); 
/* Create a file locator for the new file. */
var fileLocator= new EntityFileLocator("ActivityFile", fileId); 
/* Get an IFile object for the new file. */ 
IFile file = UserConnection.CreateFile(fileLocator); 
/* There is no file metadata or file content in the available file storages. Specify the file name in the file metadata. */
file.Name = "New file"; 
/* Set an attribute for the new file: bind the file to an Activity record with the activityId key. This is file metadata as well. */
file.SetAttribute("ActivityId", activityId); 
/* Save the file metadata Do this BEFORE saving the content. */
file.Save(); 
/* byte[] content – this is the file contents. */
var content = new byte[] {0x12, 0x34, 0x56}; 
using (var stream = new MemoryStream(content)) { 
    /* Save the content to the database. FileWriteOptions.SinglePart implies that the contents will be transferred without breaking into smaller parts. */
    file.Write(stream, FileWriteOptions.SinglePart); 
}

Example. Get the file content.

Read the file content
using Terrasoft.Common;

var content = new byte[]();
Guid recordId = Guid.NewGuid();

/* Create a file locator for the new file. */
var fileLocator = new EntityFileLocator("ActivityFile", recordId);
IFile file = UserConnection.GetFile(fileLocator);

/* Read the contents of the file in the content byte array. Remember to free the stream object by utilizing using! */
using (Stream stream = file.Read()) {
   content = stream.ReadToEnd();
}

Example. Copy a file, then move it to a new location and delete it.

Copy, move, and delete a file
var content = new byte[](); 
/* Get the file with the file locator. */
var fileLocator = new EntityFileLocator("ActivityFile", fileId); 
IFile file = UserConnection.GetFile(fileLocator); 
/* Read the contents of the file in the content byte array. Remember to free the stream object by utilizing using! */
using (Stream stream = file.Read()) { 
    content = stream.ReadToEnd(); 
} 
/* Copy the file. */ 
  
/* Create a new IFile to copy the current file. */ 
Guid copyFileId = Guid.NewGuid();
var copyFileLocator = new EntityFileLocator("ActivityFile", copyFileId);
IFile copyFile = UserConnection.CreateFile(copyFileLocator); 
copyFile.Name = file.Name + " - Copy"; 
copyFile.Save(); 
  
/* Copy the contents of the first file to the new file. */ 
copyFile.Write(new MemoryStream(content), FileWriteOptions.SinglePart); 
  
/* An alternate way to copy the file. */
file.Copy(copyFile); 
  
/* Move the file. */
  
/* Create a new file to copy the current file. */ 
Guid moveFileId = Guid.NewGuid();
var moveFileLocator = new EntityFileLocator("ContactFile", moveFileId); IFile moveFile = UserConnection.CreateFile(moveFileLocator); 
moveFile.Save(); 
  
/* Move to the new location. */ 
file.Move(moveFile); 
  
/* Delete the original file. */
file.Delete();
Implement a file content storage
Medium

Example. Create a class that implements the IFileContentStorage interface to create a content storage in the file system.

Implement a file content storage
namespace Terrasoft.Configuration
{
   using System.IO;
   using System.Threading.Tasks;
   using Terrasoft.File.Abstractions;
   using Terrasoft.File.Abstractions.Content;
   using Terrasoft.File.Abstractions.Metadata;
   using Terrasoft.File.Metadata;
 
   /// <summary>
   /// Content storage in the file system.
   /// </summary>
   public class FsFileBlobStorage : IFileContentStorage
   {
       
      // A root path to the storage.
      private const string BaseFsPath = "C:\\FsStore\\";
       
      private static string GetPath(FileMetadata fileMetadata) {
         var md = (EntityFileMetadata)fileMetadata;
         string key = $"{md.EntitySchemaName}\\{md.RecordId}_{fileMetadata.Name}";
         return Path.Combine(BaseFsPath, key);
      }
 
      public Task<Stream> ReadAsync(IFileContentReadContext context) {
         string filePath = GetPath(context.FileMetadata);
         Stream stream = System.IO.File.OpenRead(filePath);
         return Task.FromResult(stream);
      }
 
      public async Task WriteAsync(IFileContentWriteContext context) {
         string filePath = GetPath(context.FileMetadata);
         FileMode flags = context.WriteOptions != FileWriteOptions.SinglePart
            ? FileMode.Append
            : FileMode.OpenOrCreate;
         string dirPath = Path.GetDirectoryName(filePath);
         if (!Directory.Exists(dirPath)) {
            Directory.CreateDirectory(dirPath);
         }
         using (var fileStream = System.IO.File.Open(filePath, flags)) {
            context.Stream.CopyToAsync(fileStream);
         }
      }
       
      public Task DeleteAsync(IFileContentDeleteContext context) {
         string filePath = GetPath(context.FileMetadata);
         System.IO.File.Delete(filePath);
         return Task.CompletedTask;
      }
       
      public Task CopyAsync(IFileContentCopyMoveContext context) {
         string sourceFilePath = GetPath(context.SourceMetadata);
         string targetFilePath = GetPath(context.TargetMetadata);
         System.IO.File.Copy(sourceFilePath, targetFilePath);
         return Task.CompletedTask;
      }
       
      public Task MoveAsync(IFileContentCopyMoveContext context) {
         string sourceFilePath = GetPath(context.SourceMetadata);
         string targetFilePath = GetPath(context.TargetMetadata);
         System.IO.File.Move(sourceFilePath, targetFilePath);
         return Task.CompletedTask;
      }
   }
}

 

IFile interface
Medium

Terrasoft.File.Abstractions namespace.

The Terrasoft.File.Abstractions.IFile interface provides essential file management methods applicable in any file storage. The methods of this interface are used for asynchronous file management. Synchronous file management methods are available in the Terrasoft.File.Abstractions.FileUtils derived class.

Properties 

FileLocator IFileLocator

The file locator connected to the current instance of the class that implements the IFile interface.

Name string

File name.

Length long

The size of the current file in bytes.

CreatedOn DateTime

Date and time the file was created.

ModifiedOn DateTime

Date and time the file was modified.

Exists bool

Checks if the current file exists.

Methods 

Task CopyAsync(IFile target)

Copies the current file to the new target asynchronously.

Task MoveAsync(IFile target)

Moves the current file to the new target asynchronously.

Task DeleteAsync()

Deletes the current file asynchrously.

Task WriteAsync(Stream stream, FileWriteOptions writeOptions)

Writes the contents of the current file to the stream asynchronously.

Task<Stream> ReadAsync()

Reads the contents of the current file asynchronously.

Task SaveAsync()

Saves the metadata of the current file asynchronously.

void SetAttribute<TValue>(string name, TValue value)

Sets value of the name attribute for the current file.

TValue GetAttribute<TValue>(string name, TValue defaultValue)

Returns the attribute value or the default value for the current file.

IFileContentStorage interface
Medium

Terrasoft.File.Abstractions namespace.

The Terrasoft.File.Abstractions.IFileContentStorage interface provides the essential methods for file storage management. 

Methods 

Task<Stream> ReadAsync(IFileContentReadContext context)

Reads the file content.

Task WriteAsync(IFileContentWriteContext context)

Writes the file content.

Task DeleteAsync(IFileContentDeleteContext context)

Deletes the file content.

Task CopyAsync(IFileContentCopyMoveContext context)

Copies the file content.

Task MoveAsync(IFileContentCopyMoveContext context)

Moves the file content.

IFileFactory interface
Medium

Terrasoft.File.Abstractions namespace.

The Terrasoft.File.Abstractions.IFileFactory interface provides a set of methods to get or create an instance of the class that implements the Terrasoft.File.Abstractions.IFile interface.

Properties 

UseRights bool

Determines if the permissions of the user are considered when creating a file.

Methods 

IFile Get(IFileLocator fileLocator, FileOptions options)

Returns an instance of the class that implements the IFile interface with the specified options parameters from a given fileLocator

IFile Create(IFileLocator fileLocator, FileOptions options)

Creates an instance of the class that implements the IFile interface with the specified options parameters for a given fileLocator.

EntityFileLocator class
Medium

Terrasoft.File namespace.

The class implements the IFileLocator interface for the current Creatio file storage.

Constructors 

EntityFileLocator()

Creates a new EntityFileLocator instance.

EntityFileLocator(string entitySchemaName, Guid recordId)

Creates a new EntityFileLocator instance for the specified recordId file bound to the entitySchemaName object schema.

Properties 

EntitySchemaName string

Metadata – the name of the object that stores the file.

RecordId Guid

Metadata – the file ID

EntityFileMetadata class
Medium

Terrasoft.File namespace.

The Terrasoft.File.EntityFileMetadata class implements the Terrasoft.File.Abstractions.Metadata.FileMetadata abstract class. This class describes the file metadata in the [Attachments] object and provide the methods to manage them.

Constructors 

EntityFileMetadata(EntityFileLocator fileLocator)

Creates an EntityFileMetadata instance for a given fileLocator.

Properties 

Attributes IReadOnlyDictionary<string, object>

Collection of attribute values.

RecordId Guid

File ID.

EntitySchemaName string

The name of the object that stores the file.

Methods 

override void SetAttribute<TValue>(string name, TValue value)

Set the additional name file attribute to the specified value.

override TValue GetAttribute<TValue>(string name, TValue defaultValue)

Returns the specified value or the defaultValue of the additional name attribute .

FileFactoryUtils class
Medium

Terrasoft.File namespace.

The Terrasoft.File.FileFactoryUtils class provides extension methods for the UserConnection class and factory class that implements the Terrasoft.File.AbstractionsIFileFactory interface. This way, the class provides access to the factory for creating new or getting existing files. Therefore, an instance of UserConnection or SystemUserConnection is required for file management.

Methods 

static IFileFactory GetFileFactory(this UserConnection source)

An extension method for the UserConnection class that returns an instance of the class that implements the IFileFactory interface.

static IFile GetFile(this UserConnection source, IFileLocator fileLocator)

An extension method for the UserConnection class that returns an instance of the class that implements the IFile interface from a given fileLocator.

static IFile CreateFile(this UserConnection source, IFileLocator fileLocator)

An extension method for the UserConnection class that creates an instance of the class that implements the IFile interface from a given fileLocator.

static IFile Get(this IFileFactory source, IFileLocator fileLocator)

An extension method for the class that implements the IFileFactory interface. Returns an instance of the class that implements the IFile interface for a given fileLocator.

static IFile Create(this IFileFactory source, IFileLocator fileLocator)

An extension method for the class that implements the IFileFactory interface. Creates an instance of the class that implements the IFile interface for a given fileLocator.

static IFileFactory WithRightsDisabled(this IFileFactory source)

An extension method for the class that implements the IFileFactory interface. Returns an instance of the class that implements the IFileFactory interface configured without the access permissions of the user.

FileMetadata class
Medium

Terrasoft.File.Abstractions.Metadata namespace.

The Terrasoft.File.Abstractions.Metadata.FileMetadata abstract class provides the properties of file metadata and methods for metadata management,

Properties 

Name string

File name.

Length long

The file size in bytes.

CreatedOn DateTime

Date and time the file was created.

ModifiedOn DateTime

Date and time the file was modified.

FileContentStorageId Guid

The identifier of the file storage.

StoringState FileStoringState

The state of the file (“New,” “Modified,” “Unmodified,” “Deleted”).

Methods 

abstract void SetAttribute<TValue>(string name, TValue value)

Set the additional name file attribute to the specified value.

abstract TValue GetAttribute<TValue>(string name, TValue defaultValue)

Returns the specified value or the defaultValue of the additional name attribute .

void SetStoringState(FileStoringState newState)

Sets the file state to FileStoringState.Modified if the previous file state is not FileStoringState.New.

FileUtils class
Medium

Terrasoft.File.Abstractions namespace.

The Terrasoft.File.Abstractions.FileUtils class provides extension methods for file management.

Methods 

static void SetAttributes(this IFile source, IReadOnlyDictionary<string, object> attributes)

Sets the file attributes to the values passed in the attributes collection.

static void Save(this IFile source)

Saves the metadata of the file.

static Stream Read(this IFile source)

Reads the content of the file.

static void Write(this IFile source, Stream stream, FileWriteOptions writeOptions) static void Write(this IFile source, byte[] content)

Writes the content of the file.

Parameters
source The file whose contents is to be written
stream The stream that provides the file content.
writeOptions Parameters for writing the file.
content The file content as an array of bytes.
static void Delete(this IFile source)

Deletes the specified file.

static void Copy(this IFile source, IFile target)

Copies the existing source file to the new target file.

static void Move(this IFile source, IFile target)

Moves the existing source file to the new target destination.