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decrypt Method

Summary

Decrypt this document using the specified password.

Syntax

TypeScript

JavaScript

LEADDocument.prototype.decrypt = function( 
   password 
)

decrypt( 
   password: string 
): JQueryPromise<LEADDocument>;

Parameters

password

String containing the password phrase to decrypt this document.

Return Value

A Promise object that may resolve successfully to the same LEADDocument object.

Remarks

In most cases, the LEADDocument is ready to use after it has been obtained. However, some documents such as PDF can be encrypted and required a password before it 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.

For more information, refer to Loading Encrypted Files Using the Document Library.

Example

IsEncrypted.ts

DocumentHelper.ts

IsEncrypted.js

DocumentHelper.js

IsEncrypted.html

import { DocumentHelper } from "../../utilities/DocumentHelper"; 
 
export class LEADDocument_IsEncryptedExample { 
   public constructor() { 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
      DocumentHelper.initFactory(); 
   } 
 
   public run = (buttonID: string) => { 
      const exampleButton = document.getElementById(buttonID); 
      exampleButton.onclick = this.isEncrypted; 
   } 
 
   /** 
    * Checks a LEADDocument to see if it is encrypted. 
    * We will assume that the document being loaded is encrypted with a password. 
    */ 
   isEncrypted = () => { 
      const url = "https://demo.leadtools.com/images/pdf/leadtools.pdf"; 
      const password = "password"; 
      const loadDocumentOptions = new lt.Document.LoadDocumentOptions(); 
 
      // Note: That you can set the password directory here into loadDocumentOptions.password and the document will be decrypted 
      // automatically by the service. This example assumes that the password is not known in advance and will be obtained from the 
      // user. 
 
      lt.Document.DocumentFactory.loadFromUri(url, loadDocumentOptions) 
         .done((document: lt.Document.LEADDocument) => { 
            DocumentHelper.log("Document loaded...", document); 
            if (document.isEncrypted && !document.isDecrypted) { 
               // We need to decrypt it before we can use it 
               DocumentHelper.log("Document is encrypted. Number of pages will be incorrect: " + document.pages.count); 
               DocumentHelper.log("Decrypting..."); 
               document.decrypt(password) 
                  .done((document: lt.Document.LEADDocument) => { 
                     DocumentHelper.log("Document is now decrypted. Number of pages: " + document.pages.count); 
                  }) 
                  .fail(DocumentHelper.showServiceError) 
                  .always(() => { 
                     DocumentHelper.log("Complete."); 
                  }); 
            } 
 
         }) 
         .fail(DocumentHelper.showServiceError); 
   } 
}

export class DocumentHelper { 
   static showServiceError = (jqXHR, statusText, errorThrown) => { 
      alert("Error returned from service. See the console for details."); 
      const serviceError = lt.Document.ServiceError.parseError(jqXHR, statusText, errorThrown); 
      console.error(serviceError); 
   } 
 
   static log = (message: string, data?: any) => { 
      const outputElement = document.getElementById("output"); 
      if (outputElement) { 
         const time = (new Date()).toLocaleTimeString(); 
         const textElement = document.createElement("p"); 
         textElement.innerHTML = (outputElement.childElementCount + 1) + " [" + time + "]: " + message; 
         outputElement.insertBefore(textElement, outputElement.firstChild); 
      } 
 
      if (!data) 
         console.log(message); 
      else 
         console.log(message, data); 
   } 
 
   static initFactory = () => { 
      // 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:40000"; 
      lt.Document.DocumentFactory.servicePath = ""; 
      lt.Document.DocumentFactory.serviceApiPath = "api"; 
   } 
}

import { DocumentHelper } from "../../utilities/DocumentHelper"; 
 
export class LEADDocument_IsEncryptedExample { 
   constructor() { 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
      DocumentHelper.initFactory(); 
   } 
 
   run = (buttonID) => { 
      const exampleButton = document.getElementById(buttonID); 
      exampleButton.onclick = this.isEncrypted; 
   } 
 
   /** 
    * Checks a LEADDocument to see if it is encrypted. 
    * We will assume that the document being loaded is encrypted with a password. 
    */ 
   isEncrypted = () => { 
      const url = "https://demo.leadtools.com/images/pdf/leadtools.pdf"; 
      const password = "password"; 
      const loadDocumentOptions = new lt.Document.LoadDocumentOptions(); 
 
      // Note: That you can set the password directory here into loadDocumentOptions.password and the document will be decrypted 
      // automatically by the service. This example assumes that the password is not known in advance and will be obtained from the 
      // user. 
 
      lt.Document.DocumentFactory.loadFromUri(url, loadDocumentOptions) 
         .done((document) => { 
            DocumentHelper.log("Document loaded...", document); 
            if (document.isEncrypted && !document.isDecrypted) { 
               // We need to decrypt it before we can use it 
               DocumentHelper.log("Document is encrypted. Number of pages will be incorrect: " + document.pages.count); 
               DocumentHelper.log("Decrypting..."); 
               document.decrypt(password) 
                  .done((document) => { 
                     DocumentHelper.log("Document is now decrypted. Number of pages: " + document.pages.count); 
                  }) 
                  .fail(DocumentHelper.showServiceError) 
                  .always(() => { 
                     DocumentHelper.log("Complete."); 
                  }); 
            } 
 
         }) 
         .fail(DocumentHelper.showServiceError); 
   } 
}

export class DocumentHelper { 
   static showServiceError = (jqXHR, statusText, errorThrown) => { 
      alert("Error returned from service. See the console for details."); 
      const serviceError = lt.Document.ServiceError.parseError(jqXHR, statusText, errorThrown); 
      console.error(serviceError); 
   } 
 
   static log = (message, data) => { 
      const outputElement = document.getElementById("output"); 
      if (outputElement) { 
         const time = (new Date()).toLocaleTimeString(); 
         const textElement = document.createElement("p"); 
         textElement.innerHTML = (outputElement.childElementCount + 1) + " [" + time + "]: " + message; 
         outputElement.insertBefore(textElement, outputElement.firstChild); 
      } 
 
      if (!data) 
         console.log(message); 
      else 
         console.log(message, data); 
   } 
 
   static initFactory = () => { 
      // 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:40000"; 
      lt.Document.DocumentFactory.servicePath = ""; 
      lt.Document.DocumentFactory.serviceApiPath = "api"; 
   } 
}

<!doctype html> 
<html lang="en"> 
<title>Document Example | IsEncrypted</title> 
 
<head> 
   <script src="https://code.jquery.com/jquery-2.2.4.min.js" 
      integrity="sha256-BbhdlvQf/xTY9gja0Dq3HiwQF8LaCRTXxZKRutelT44=" crossorigin="anonymous"></script> 
 
   <script src="../../LT/Leadtools.js"></script> 
   <script src="../../LT/Leadtools.Controls.js"></script> 
   <script src="../../LT/Leadtools.Annotations.Engine.js"></script> 
   <script src="../../LT/Leadtools.Annotations.Designers.js"></script> 
   <script src="../../LT/Leadtools.Annotations.Rendering.Javascript.js"></script> 
   <script src="../../LT/Leadtools.Annotations.Automation.js"></script> 
   <script src="../../LT/Leadtools.ImageProcessing.Main.js"></script> 
   <script src="../../LT/Leadtools.ImageProcessing.Color.js"></script> 
   <script src="../../LT/Leadtools.ImageProcessing.Core.js"></script> 
   <script src="../../LT/Leadtools.ImageProcessing.Effects.js"></script> 
   <script src="../../LT/Leadtools.Document.js"></script> 
   <script src="../../LT/Leadtools.Document.Viewer.js"></script> 
   <link rel="stylesheet" type="text/css" href="../../css/examples.css"> 
 
   <!-- All demo files are bundled and appended to the window --> 
   <script src="../../bundle.js" type="text/javascript"></script> 
</head> 
 
<body> 
   <div> 
      <button type="button" id="exampleButton">Run Example</button> 
   </div> 
   <div id="output"></div> 
   <div> 
      <img id="img" /> 
   </div> 
</body> 
 
<script> 
   window.onload = () => { 
      const example = new window.examples.LEADDocument.IsEncrypted(); 
      example.run("exampleButton"); 
   }; 
</script> 
</html>