GetDocumentCacheInfo(ObjectCache,string) Method

Summary

Retrieves information for a document in the cache using its ID.

Syntax

C++

public static DocumentCacheInfo GetDocumentCacheInfo( 
   ObjectCache cache, 
   string documentId 
)

Public Shared Function GetDocumentCacheInfo( 
   ByVal cache As ObjectCache, 
   ByVal documentId As String 
) As DocumentCacheInfo

public:  
   static DocumentCacheInfo^ GetDocumentCacheInfo( 
      ObjectCache^ cache, 
      String^ documentId 
   )

Parameters

cache

The cache object to use. This value cannot be null.

documentId

The document identifier. This value cannot be null.

Return Value

DocumentCacheInfo object that contains the information of the document referenced by documentId such as its name, mime type, page count if the document was found in the cache; otherwise, null if no document with the ID specified by documentId was found in the cache.

Remarks

Use GetDocumentCacheInfo to quickly obtain information on a document in the cache without loading it. This includes whether the document is in the cache, its name and mime type, the number of pages and whether it was loaded by the user.

Example

This example shows how to use GetDocumentCacheInfo to get information on a document in the cache in various stages.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Document.Writer; 
 
using Leadtools.Document; 
using Leadtools.Caching; 
using Leadtools.Annotations.Engine; 
using Leadtools.Ocr; 
using Leadtools.Barcode; 
using Leadtools.Document.Converter; 
 
public void GetDocumentCacheInfoExample() 
{ 
	string documentFile = Path.Combine(LEAD_VARS.ImagesDir, "Leadtools.pdf"); 
 
	// Setup a cache 
	FileCache cache = new FileCache(); 
	cache.CacheDirectory = @"c:\cache-dir"; 
 
	// We will use this document ID 
	const string documentId = "test-document"; 
 
	// Ensure that the document does not exist in the cache 
	var deleteFromCacheOptions = new LoadFromCacheOptions(); 
	deleteFromCacheOptions.Cache = cache; 
	deleteFromCacheOptions.DocumentId = documentId; 
	DocumentFactory.DeleteFromCache(deleteFromCacheOptions); 
 
	DocumentCacheInfo cacheInfo; 
 
	// Now get the info for this document, it should not exist 
	cacheInfo = DocumentFactory.GetDocumentCacheInfo(cache, documentId); 
	Debug.Assert(cacheInfo == null); 
 
	// Next, upload a document into this cache 
	var uploadDocumentOptions = new UploadDocumentOptions(); 
	uploadDocumentOptions.Cache = cache; 
	uploadDocumentOptions.DocumentId = documentId; 
	uploadDocumentOptions.Name = "Leadtools.pdf"; 
	Uri uploadUri = DocumentFactory.BeginUpload(uploadDocumentOptions); 
	using (var stream = File.OpenRead(documentFile)) 
	{ 
		var buffer = new byte[stream.Length]; 
		stream.Read(buffer, 0, buffer.Length); 
		DocumentFactory.UploadDocument(cache, uploadUri, buffer, 0, buffer.Length); 
	} 
	DocumentFactory.EndUpload(cache, uploadUri); 
 
	// Now check the info again, it should be there but not loaded 
	cacheInfo = DocumentFactory.GetDocumentCacheInfo(cache, documentId); 
	Console.WriteLine("After upload"); 
	Console.WriteLine("   DocumentId:" + cacheInfo.DocumentId); 
	Console.WriteLine("   Name:" + cacheInfo.Name); 
	Console.WriteLine("   IsLoaded:" + cacheInfo.IsLoaded); 
	Debug.Assert(cacheInfo.DocumentId == documentId); 
	Debug.Assert(cacheInfo.Name == "Leadtools.pdf"); 
	Debug.Assert(!cacheInfo.IsLoaded); 
 
	// Next load this document 
	var loadDocumentOptions = new LoadDocumentOptions(); 
	loadDocumentOptions.Cache = cache; 
	using (var document = DocumentFactory.LoadFromUri(uploadUri, loadDocumentOptions)) 
	{ 
		// Save it to the cache 
		document.AutoSaveToCache = false; 
		document.AutoDeleteFromCache = false; 
		document.SaveToCache(); 
	} 
 
	// Now get its info again, it should be there and loaded 
	cacheInfo = DocumentFactory.GetDocumentCacheInfo(cache, documentId); 
	Console.WriteLine("After load"); 
	Console.WriteLine("   DocumentId:" + cacheInfo.DocumentId); 
	Console.WriteLine("   Name:" + cacheInfo.Name); 
	Console.WriteLine("   IsLoaded:" + cacheInfo.IsLoaded); 
	Debug.Assert(cacheInfo.DocumentId == documentId); 
	Debug.Assert(cacheInfo.Name == "Leadtools.pdf"); 
	Debug.Assert(cacheInfo.IsLoaded); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Document.Writer 
Imports Leadtools.Svg 
Imports Leadtools.Document 
Imports Leadtools.Caching 
Imports Leadtools.Annotations.Engine 
Imports Leadtools.Barcode 
Imports Leadtools.Ocr 
Imports LeadtoolsDocumentExamples.LeadtoolsExamples.Common 
Imports Leadtools.Document.Converter 
 
Public Shared Sub GetDocumentCacheInfoExample() 
   Dim documentFile As String = Path.Combine(ImagesPath.Path, "Leadtools.pdf") 
 
   ' Setup a cache 
   Dim Cache As New FileCache() 
   Cache.CacheDirectory = "c:\cache-dir" 
 
   ' We will use this document ID 
   Const documentId As String = "test-document" 
 
   ' Ensure that the document does Not exist in the cache 
   Dim deleteFromCacheOptions As New LoadFromCacheOptions 
   deleteFromCacheOptions.Cache = Cache 
   deleteFromCacheOptions.DocumentId = documentId 
   DocumentFactory.DeleteFromCache(deleteFromCacheOptions) 
 
   Dim cacheInfo As DocumentCacheInfo 
 
   ' Now get the info for this document, it should Not exist 
   cacheInfo = DocumentFactory.GetDocumentCacheInfo(Cache, documentId) 
   Debug.Assert(IsNothing(cacheInfo)) 
 
   ' Next, upload a document into this cache 
   Dim UploadDocumentOptions As New UploadDocumentOptions() 
   UploadDocumentOptions.Cache = Cache 
   UploadDocumentOptions.DocumentId = documentId 
   UploadDocumentOptions.Name = "Leadtools.pdf" 
   Dim uploadUri As Uri = DocumentFactory.BeginUpload(UploadDocumentOptions) 
   Using stream As Stream = File.OpenRead(documentFile) 
      Dim buffer(CType(stream.Length - 1, Integer)) As Byte 
      stream.Read(buffer, 0, buffer.Length) 
      DocumentFactory.UploadDocument(Cache, uploadUri, buffer, 0, buffer.Length) 
   End Using 
   DocumentFactory.EndUpload(Cache, uploadUri) 
 
   ' Now check the info again, it should be there but Not loaded 
   cacheInfo = DocumentFactory.GetDocumentCacheInfo(Cache, documentId) 
   Console.WriteLine("After upload") 
   Console.WriteLine("   DocumentId:" + cacheInfo.DocumentId) 
   Console.WriteLine("   Name:" + cacheInfo.Name) 
   Console.WriteLine("   IsLoaded:" + cacheInfo.IsLoaded.ToString()) 
   Debug.Assert(cacheInfo.DocumentId = documentId) 
   Debug.Assert(cacheInfo.Name = "Leadtools.pdf") 
   Debug.Assert(Not cacheInfo.IsLoaded) 
 
   ' Next load this document 
   Dim LoadDocumentOptions As New LoadDocumentOptions() 
   LoadDocumentOptions.Cache = Cache 
   Using document As LEADDocument = DocumentFactory.LoadFromUri(uploadUri, LoadDocumentOptions) 
      ' Save it to the cache 
      document.AutoSaveToCache = False 
      document.AutoDeleteFromCache = False 
      document.SaveToCache() 
   End Using 
 
   ' Now get its info again, it should be there And loaded 
   cacheInfo = DocumentFactory.GetDocumentCacheInfo(Cache, documentId) 
   Console.WriteLine("After load") 
   Console.WriteLine("   DocumentId:" + cacheInfo.DocumentId) 
   Console.WriteLine("   Name:" + cacheInfo.Name) 
   Console.WriteLine("   IsLoaded:" + cacheInfo.IsLoaded.ToString()) 
   Debug.Assert(cacheInfo.DocumentId = documentId) 
   Debug.Assert(cacheInfo.Name = "Leadtools.pdf") 
   Debug.Assert(cacheInfo.IsLoaded) 
End Sub

Requirements

Target Platforms

Reference

DocumentFactory Class

DocumentFactory Members

Leadtools.Document Namespace

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Leadtools.Document Assembly

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