LEADDocument Object

Summary

Encapsulates a multi-page document with support for raster and SVG images, bookmarks, annotations and text data.

Syntax

JavaScript Syntax
function lt.Document.LEADDocument 
TypeScript Syntax
class lt.Document.LEADDocument() 

Remarks

The LEADDocument class provides uniform support for any type of document. The actual data behind can be a PDF document, Microsoft Word document, TIFF image, AutoCAD DWG drawing or any other of the hundreds of different raster, document or vector file formats supported by LEADTOOLS. LEADDocument encapsulates the common functionality needed to access this data in a uniform manner with the same properties, methods and data structures.

Document Viewer

LEADDocument is used as an input to the LEADTOOLS DocumentViewer, which can be used to view the document and its pages with thumbnails, virtualization, text search and annotation support.

Creating a Document Class

A LEADDocument instance be obtained using the following:

Method Description
DocumentFactory.LoadFromUri Creates a new instance from a document stored in a remote URL.
DocumentFactory.LoadFromCache Loads a previously saved document from the cache.
DocumentFactory.Create Creates a new empty document.

Encryption

In most cases, the LEADDocument is ready to use after it has been obtained. However, some documents such as PDF can be encrypted and require a password before they can be parsed and used. Most of the properties and methods of LEADDocument will throw an error if the document has not been decrypted. IsEncrypted can be used to check if the document is encrypted and if so, Decrypt must be called with a password obtained from the user to unlock the document. When that happens, the value of IsDecrypted becomes true and the document is ready to be used. Note that IsEncrypted will stay true to indicate the original state of the document.

Document Identifier

Each document has a unique identifier that is set at creation time by the framework. This is stored in the DocumentId property. The ID is important when using the document with the cache system and is the only value needed to re-construct completely the document from the cache. The document ID can be set manually by the user through the LoadDocumentOptions.DocumentId, CreateDocumentOptions.DocumentId or BeginUpload options used when loading, creating or uploading the document. If the value was left to null, then the factory will generate a new random ID to associate with.

Caching

Documents can contain large number of pages and huge amount of data. Storing all this data in the physical memory is not feasible in most situations. Therefore, the LEADDocument class was designed to use an external caching system to store previously requested document sections and document modifications.

Structure and Table of Contents

DocumentStructure manages the structure of the document. This includes the bookmarks that represent the table of contents. They can be accessed through the Structure property of LEADDocument.

Pages

DocumentPages manages the pages of the document. It can be accessed through the Pages property of LEADDocument. DocumentPages is a standard JavaScript array; you can use any of the collection methods to add, remove, insert, get, set and iterate through the DocumentPage items. The DocumentPage is the main entry point for using the documents in a viewer or converter application. It contains functions to retrieve or update the raster or SVG image of the page, text data, annotations and hyperlinks.

Documents

DocumentDocuments manages the child documents of the document. It can be accessed through the Documents property of LEADDocument.

DocumentDocuments derives from LeadCollection. You can use any of the collection methods to iterate through the documents. This collection is read-only however and you cannot add, remove or change the items. Instead, use Pages to add or remove pages that belong to a separate document to this one. The LEADDocument.Documents collection will automatically get updated to reflect what child documents are currently held in the document.

Metadata

The metadata includes default values added by the service when the document is loaded or created, as well as any other data extracted from the document file itself such as author, subject and any keywords stored by other applications.

Properties

The following properties are part of LEADDocument and contain useful information:

  • DocumentId: The unique identifier of this document.

  • Name: The optional name of this document.

  • MimeType: The MIME type of the document.

  • Uri: The URL to the original document physical location. If this is a newly created document then Uri will be null.

  • CacheUri: The URL to the original document's image data if it was stored in the cache.

  • IsReadOnly: Determines if the document is read-only and cannot be changed.

  • FileLength: The length of the original document file or URL in bytes.

  • CacheStatus: The status of this document in the cache.

Global Document Settings

The LEADDocument class contains the following to manage global settings used throughout the document.

  • Images: Manages the raster and SVG image settings of the document.

  • Annotations: Manages the annotations settings of the document.

  • Text: Manages the text and OCR recognition settings of the document.

  • Barcodes: Manages the barcode settings of the document.

Document Units

LEADDocument uses independent units of 1/720 of an inch for all items. This value is stored in UnitsPerInch constant (720). Refer to Documents Library Coordinate System for more information.

Example

This example will set up the LEADTOOLS Documents Service and load a PDF document. This example is used as the basis for examples for most other members in this namespace.

JavaScript Example
<!DOCTYPE html> 
<html> 
 
<head> 
   <title>Leadtools Examples</title> 
   <meta http-equiv="content-type" content="text/html; charset=utf-8" /> 
   <script type="text/javascript" src="https://code.jquery.com/jquery-2.1.1.min.js"></script> 
   <script type="text/javascript" src="Scripts/Leadtools.js"></script> 
   <script type="text/javascript" src="Scripts/Leadtools.Controls.js"></script> 
   <script type="text/javascript" src="Scripts/Leadtools.Document.js"></script> 
   <script type="text/javascript"> 
      // Elements 
      var serviceStatus, output, img; 
 
      // 
      // Helper Methods 
      // 
 
      var logNum = 1; 
      // Logs messages to the console and the screen. 
      function log(message, data) { 
         var time = (new Date()).toLocaleTimeString(); 
         var textElement = document.createElement("p"); 
         textElement.innerHTML = (logNum++) + " [" + time + "]: " + message; 
         output.insertBefore(textElement, output.firstChild); 
         if (!data) 
            console.log(message); 
         else 
            console.log(message, data); 
      } 
 
      // Parses error information. 
      function showServiceError(jqXHR, statusText, errorThrown) { 
         alert("Error returned from service. See the console for details.") 
         var serviceError = lt.Document.ServiceError.parseError(jqXHR, statusText, errorThrown); 
         console.error(serviceError); 
      } 
 
      // Startup function 
      document.addEventListener("DOMContentLoaded", function () { 
         // Get our commonly-used elements 
         img = document.getElementById("img"); 
         serviceStatus = document.getElementById("serviceStatus"); 
         output = document.getElementById("output"); 
 
         var exampleButton = document.getElementById("exampleButton"); 
         exampleButton.addEventListener("click", function (e) { 
            // Run the example 
            example(); 
         }, false); 
 
         // To communicate with the DocumentsService, it must be running! 
         // Change these parameters to match the path to the service. 
         lt.Document.DocumentFactory.serviceHost = "http://localhost:20000"; 
         lt.Document.DocumentFactory.servicePath = ""; 
         lt.Document.DocumentFactory.serviceApiPath = "api"; 
 
         serviceStatus.innerHTML = "Connecting to service: " + lt.Document.DocumentFactory.serviceUri; 
         lt.Document.DocumentFactory.verifyService() 
            .done(function (serviceData) { 
               serviceStatus.innerHTML = "Service connection verified!"; 
               log("Connected"); 
            }) 
            .fail(showServiceError) 
            .fail(function () { 
               serviceStatus.innerHTML = "Service not properly connected."; 
            }); 
      }); 
 
      //////////////////////////////////////////////////// 
 
      function example() { 
         // TODO: add example code here 
         alert("Run specific example code here!"); 
      }; 
 
   </script> 
   <style> 
      body { 
         font-family: monospace; 
      } 
 
      button { 
         margin: 5px 0; 
      } 
 
      img { 
         width: 200px; 
         border: 2px solid black; 
      } 
   </style> 
</head> 
 
<body> 
   <div> 
      <button type="button" id="exampleButton">Run Example</button> 
   </div> 
   <div> 
      <img id="img" /> 
   </div> 
   <div id="serviceStatus"></div> 
   <div id="output"></div> 
</body> 
 
</html> 

Requirements

Target Platforms

Help Version 20.0.2018.2.28
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Leadtools.Document Assembly