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LTHelper Object

Summary

Represents a helper class used by the various LEADTOOLS components to detect the current browser and operating system.

Syntax

TypeScript

JavaScript

function lt.LTHelper

class lt.LTHelper()

Remarks

LTHelper is used by the various LEADTOOLS components to detect the current browser and operating system. The capabilities and support of the various combinations are used to optimize the operation of the component.

This class is initialized automatically when the application starts. You can use the values of the properties in your own operations. However, do not change them.

Example

This example will show the various LTHelper's properties for the current browser.

LTHelper.ts

LTHelper.js

LTHelper.html

export class LTHelperExample { 
   constructor() { 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
   } 
 
   public run = (buttonId: string, outputId: string) => { 
      const button = document.getElementById(buttonId); 
      button.onclick = () => { 
         const lines: string[] = this.getInfo(); 
         // Log 
         console.log(lines); 
 
         // Create a table from the info 
         const table = document.getElementById(outputId); 
         lines.forEach((line) => { 
            const row = document.createElement("tr"); 
 
            // [0] is name 
            const name = document.createElement("th"); 
            name.innerHTML = line[0]; 
 
            // [1] is content 
            const content = document.createElement("td"); 
            content.innerHTML = line[1]; 
 
            row.appendChild(name); 
            row.appendChild(content); 
 
            //output.appendChild(row); 
            table.appendChild(row); 
         }); 
      } 
   } 
 
   public getInfo = (): string[] => { 
      // This will hold tuples like ["OS", "Windows"] 
      let lines = []; 
 
      // Show the Operating System 
      const osMap = {}; 
      osMap[lt.LTOS.unknown] = "Unknown"; 
      osMap[lt.LTOS.windows] = "Windows"; 
      osMap[lt.LTOS.mac] = "Mac OS"; 
      osMap[lt.LTOS.iOS] = "iOS"; 
      osMap[lt.LTOS.android] = "Android"; 
      osMap[lt.LTOS.linux] = "Linux"; 
      osMap[lt.LTOS.blackberry] = "Blackberry"; 
      osMap[lt.LTOS.webOS] = "Web OS"; 
      osMap[lt.LTOS.windows7] = "Windows 7"; 
      osMap[lt.LTOS.windows8] = "Windows 8"; 
      osMap[lt.LTOS.windows10] = "Windows 10"; 
 
      const os = osMap[lt.LTHelper.OS]; 
      lines.push(["OS", os]); 
 
      // Show the Device 
      const deviceMap = {}; 
      deviceMap[lt.LTDevice.unknown] = "Unknown"; 
      deviceMap[lt.LTDevice.desktop] = "Desktop"; 
      deviceMap[lt.LTDevice.mobile] = "Mobile"; 
      deviceMap[lt.LTDevice.tablet] = "Tablet"; 
 
      const device = deviceMap[lt.LTHelper.device]; 
      lines.push(["Device", device]); 
 
      // Show the Browser 
      const browserMap = {}; 
      browserMap[lt.LTBrowser.unknown] = "Unknown"; 
      browserMap[lt.LTBrowser.internetExplorer] = "Internet Explorer"; 
      browserMap[lt.LTBrowser.firefox] = "Firefox"; 
      browserMap[lt.LTBrowser.chrome] = "Chrome"; 
      browserMap[lt.LTBrowser.safari] = "Safari"; 
      browserMap[lt.LTBrowser.opera] = "Opera"; 
      browserMap[lt.LTBrowser.android] = "Android Browser"; 
      browserMap[lt.LTBrowser.edge] = "Edge"; 
 
      const browser = browserMap[lt.LTHelper.browser]; 
      lines.push(["Browser", browser]); 
 
      // Show version and vendor 
      lines.push(["Browser Version", lt.LTHelper.version]); 
      lines.push(["Browser Vendor", lt.LTHelper.vendor]); 
 
      // Show the "Supports" capabilities by getting keys 
      // and looking at properties that start with "supports" 
      // (Can also directly access as shown above with version and vendor) 
      const keys: string[] = Object.keys(lt.LTHelper); 
      const supportsKeyword: string = "supports"; 
      keys.forEach((key) => { 
         const supportsIndex = key.indexOf(supportsKeyword); 
         if (supportsIndex === 0) { 
            // Starts with "supports", get the value 
            const name: string = key.substr(supportsKeyword.length); 
            const isSupported: boolean = lt.LTHelper[key]; 
            lines.push(["Supports " + name, isSupported]); 
         } 
      }); 
 
      return lines; 
   } 
}

export class LTHelperExample { 
   constructor() { 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
   } 
 
   run = (buttonId, outputId) => { 
      const button = document.getElementById(buttonId); 
      button.onclick = () => { 
         const lines = this.getInfo(); 
         // Log 
         console.log(lines); 
 
         // Create a table from the info 
         const table = document.getElementById(outputId); 
         lines.forEach((line) => { 
            const row = document.createElement("tr"); 
 
            // [0] is name 
            const name = document.createElement("th"); 
            name.innerHTML = line[0]; 
 
            // [1] is content 
            const content = document.createElement("td"); 
            content.innerHTML = line[1]; 
 
            row.appendChild(name); 
            row.appendChild(content); 
 
            //output.appendChild(row); 
            table.appendChild(row); 
         }); 
      } 
   } 
 
   getInfo = () => { 
      // This will hold tuples like ["OS", "Windows"] 
      let lines = []; 
 
      // Show the Operating System 
      const osMap = {}; 
      osMap[lt.LTOS.unknown] = "Unknown"; 
      osMap[lt.LTOS.windows] = "Windows"; 
      osMap[lt.LTOS.mac] = "Mac OS"; 
      osMap[lt.LTOS.iOS] = "iOS"; 
      osMap[lt.LTOS.android] = "Android"; 
      osMap[lt.LTOS.linux] = "Linux"; 
      osMap[lt.LTOS.blackberry] = "Blackberry"; 
      osMap[lt.LTOS.webOS] = "Web OS"; 
      osMap[lt.LTOS.windows7] = "Windows 7"; 
      osMap[lt.LTOS.windows8] = "Windows 8"; 
      osMap[lt.LTOS.windows10] = "Windows 10"; 
 
      const os = osMap[lt.LTHelper.OS]; 
      lines.push(["OS", os]); 
 
      // Show the Device 
      const deviceMap = {}; 
      deviceMap[lt.LTDevice.unknown] = "Unknown"; 
      deviceMap[lt.LTDevice.desktop] = "Desktop"; 
      deviceMap[lt.LTDevice.mobile] = "Mobile"; 
      deviceMap[lt.LTDevice.tablet] = "Tablet"; 
 
      const device = deviceMap[lt.LTHelper.device]; 
      lines.push(["Device", device]); 
 
      // Show the Browser 
      const browserMap = {}; 
      browserMap[lt.LTBrowser.unknown] = "Unknown"; 
      browserMap[lt.LTBrowser.internetExplorer] = "Internet Explorer"; 
      browserMap[lt.LTBrowser.firefox] = "Firefox"; 
      browserMap[lt.LTBrowser.chrome] = "Chrome"; 
      browserMap[lt.LTBrowser.safari] = "Safari"; 
      browserMap[lt.LTBrowser.opera] = "Opera"; 
      browserMap[lt.LTBrowser.android] = "Android Browser"; 
      browserMap[lt.LTBrowser.edge] = "Edge"; 
 
      const browser = browserMap[lt.LTHelper.browser]; 
      lines.push(["Browser", browser]); 
 
      // Show version and vendor 
      lines.push(["Browser Version", lt.LTHelper.version]); 
      lines.push(["Browser Vendor", lt.LTHelper.vendor]); 
 
      // Show the "Supports" capabilities by getting keys 
      // and looking at properties that start with "supports" 
      // (Can also directly access as shown above with version and vendor) 
      const keys = Object.keys(lt.LTHelper); 
      const supportsKeyword = "supports"; 
      keys.forEach((key) => { 
         const supportsIndex = key.indexOf(supportsKeyword); 
         if (supportsIndex === 0) { 
            // Starts with "supports", get the value 
            const name = key.substr(supportsKeyword.length); 
            const isSupported = lt.LTHelper[key]; 
            lines.push(["Supports " + name, isSupported]); 
         } 
      }); 
 
      return lines; 
   } 
}

<!doctype html> 
<html lang="en"> 
<title>Leadtools Example | LTHelper</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> 
   <style> 
      td, 
      th { 
         text-align: left; 
         padding: 0 5px; 
         font-family: monospace; 
      } 
   </style> 
 
   <!-- All demo files are bundled and appended to the window --> 
   <script src="../../bundle.js" type="text/javascript"></script> 
</head> 
 
<body> 
   <button type="button" id="run">LTHelper Example</button> 
   <div> 
      <table> 
         <tbody id="output"></tbody> 
      </table> 
   </div> 
</body> 
 
<script> 
   window.onload = () => new window.examples.LTHelper().run('run', 'output'); 
</script> 
</html>

Requirements

Target Platforms

Reference

LTHelper Members

Leadtools Namespace

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Help Version 22.0.2023.2.2

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