strong-error-handler/lib/send-html.js

92 lines
2.9 KiB
JavaScript

// Copyright IBM Corp. 2016. All Rights Reserved.
// Node module: strong-error-handler
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT
'use strict';
const handlebars = require('handlebars');
const fs = require('fs');
const path = require('path');
const assetDir = path.resolve(__dirname, '../views');
const compiledTemplates = {
// loading default template and stylesheet
default: loadDefaultTemplates(),
};
module.exports = sendHtml;
/**
* Sends HTML response to the client.
*
* @param {Object} res - The response object.
* @param {Object} data - The data object to be rendered in the HTML.
* @param {Object} options - The options object.
*/
function sendHtml(res, data, options) {
const toRender = {options, data};
// TODO: ability to call non-default template functions from options
const body = compiledTemplates.default(toRender);
sendResponse(res, body);
}
/**
* Returns the content of a Handlebars partial file as a string.
* @param {string} name - The name of the Handlebars partial file.
* @returns {string} The content of the Handlebars partial file as a string.
*/
function partial(name) {
const partialPath = path.resolve(assetDir, `${name}.hbs`);
const partialContent = fs.readFileSync(partialPath, 'utf8');
return partialContent;
}
handlebars.registerHelper('partial', partial);
/**
* Checks if the given property is a standard property.
* @param {string} prop - The property to check.
* @param {Object} options - The Handlebars options object.
* @returns {string} - The result of the Handlebars template.
*/
function standardProps(prop, options) {
const standardProps = ['name', 'statusCode', 'message', 'stack'];
if (standardProps.indexOf(prop) === -1) {
return options.fn(this);
}
return options.inverse(this);
}
handlebars.registerHelper('standardProps', standardProps);
/**
* Compile and cache the file with the `filename` key in options
*
* @param filepath (description)
* @returns {Function} render function with signature fn(data);
*/
function compileTemplate(filepath) {
const options = {cache: true, filename: filepath};
const fileContent = fs.readFileSync(filepath, 'utf8');
return handlebars.compile(fileContent, options);
}
/**
* Loads the default error handlebars template from the asset directory and compiles it.
* @returns {Function} The compiled handlebars template function.
*/
function loadDefaultTemplates() {
const defaultTemplate = path.resolve(assetDir, 'default-error.hbs');
return compileTemplate(defaultTemplate);
}
/**
* Sends an HTML response with the given body to the provided response object.
* @param {Object} res - The response object to send the HTML response to.
* @param {string} body - The HTML body to send in the response.
*/
function sendResponse(res, body) {
res.setHeader('Content-Type', 'text/html; charset=utf-8');
res.end(body);
}