- /**
- * File: Includes.js
- *
- * Module used for fetching static content for the website
- * like js, css, images, and other static html pages
- *
- * @author Jeffery Russell
- */
-
- //used for file IO
- const utils = require('../utils/utils.js');
-
- //name of header file
- const HEADER_FILE = "includes/html/header.html";
-
- //path of footer file
- const FOOTER_FILE = "includes/html/footer.html";
-
- //admin header path
- const ADMIN_HEADER = "includes/html/adminHeader.html";
-
- //used for hashing stuff for the header's e-tag for clients cache
- const crypto = require('crypto');
-
-
- //caching program to make the application run faster
- const cache = require('memory-cache');
-
-
- /**
- * Sends a static file to the client in a way which the web browser
- * caches the contents sent.
- *
- * @param cache -- server's hashmap which reduces file io
- * @param path -- file requested by user
- * @param type -- type of file for the header
- * @param result -- sent to client
- */
- const sendCachedContent = function(path, type, result)
- {
- const goods = cache.get(path);
-
- if(goods == null)
- {
- utils.include("." + path).then(function(content)
- {
- const eTag = crypto.createHash('md5').update(content).digest('hex');
- result.writeHead(200, {'Content-Type': type, 'Cache-Control':
- 'public, max-age=2678400', 'ETag': '"' + eTag + '"',
- 'Vary': 'Accept-Encoding'});
- result.write(content);
- console.log(content);
- result.end();
- cache.put(path, content);
- }).catch(function(error)
- {
- console.log(error);
- });
- }
- else
- {
- const eTag = crypto.createHash('md5').update(goods).digest('hex');
- result.writeHead(200, {'Content-Type': type,
- 'Cache-Control': 'public, max-age=2678400',
- 'ETag': '"' + eTag + '"',
- 'Vary': 'Accept-Encoding'});
- result.write(goods);
- result.end();
- }
- };
-
-
- module.exports =
- {
- /** Appends the header html section to the result which is
- * sent to the user.
- *
- * @param result
- * @return {*} a promise retrieved from the utils.include function
- */
- printHeader: function()
- {
- return utils.include(HEADER_FILE);
- },
-
-
- /**
- * Appends the footer to the result object
- *
- * @return {*|Promise}
- */
- printFooter: function()
- {
- return utils.include(FOOTER_FILE);
- },
-
- /**
- * Displays the admin header
- *
- * @returns {*|Promise}
- */
- printAdminHeader()
- {
- return utils.include(ADMIN_HEADER);
- },
-
-
- /**Sends a css file to the user
- *
- * @param result
- * @param path
- * @return {*}
- */
- sendCSS: function(result, path, cache)
- {
- sendCachedContent(path, 'text/css', result);
- },
-
-
- /**Sends the user an image from the specified fileName.
- *
- * @param result
- * @param fileName
- */
- sendImage: function(result, fileName)
- {
- console.log(fileName);
- sendCachedContent(fileName, 'image/png', result);
- },
-
-
- /**Sends the user an image from the specified fileName.
- *
- * @param result
- * @param fileName
- */
- sendJS: function(result, fileName)
- {
- sendCachedContent(fileName, 'application/javascript', result);
- },
-
-
- /**Sends the user an image from the specified fileName.
- *
- * @param result
- * @param fileName
- */
- sendHTML: function(result, fileName)
- {
- utils.include("." + fileName).then(function(content)
- {
- console.log(fileName);
- console.log(content);
- result.writeHead(200, {'Content-Type': 'text/html'});
- result.write(content);
- result.end();
- }).catch(function(error)
- {
- console.log(error);
- });
- },
-
-
- /**
- * Sends a svg file to the client.
- *
- * @param result
- * @param fileName
- */
- sendSVG: function(result, fileName)
- {
- sendCachedContent(fileName, 'image/svg+xml', result);
- }
- };
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