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Support loading prerenderer boot module via Webpack config; use this in Angular 2 template

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This commit is contained in:
SteveSandersonMS
2016-03-01 00:04:51 +00:00
parent 47ba251923
commit bfc993af50
6 changed files with 179 additions and 157 deletions
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266
src/Microsoft.AspNet.SpaServices/Content/Node/prerenderer.js
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@@ -1,81 +1,65 @@
// -----------------------------------------------------------------------------------------
// Prepare the Node environment to support loading .jsx/.ts/.tsx files without needing precompilation,
// since that's such a common scenario. In the future, this might become a config option.
// This is bundled in with the actual prerendering logic below just to simplify the initialization
// logic (we can't have cross-file imports, because these files don't exist on disk until the
// StringAsTempFile utility puts them there temporarily).
// Loading via Webpack
// This is optional. You don't have to use Webpack. But if you are doing, it's extremely convenient
// to be able to load your boot module via Webpack compilation, so you can use whatever source language
// you like (e.g., TypeScript), and so that loader plugins (e.g., require('./mystyles.less')) work in
// exactly the same way on the server as you do on the client.
// If you don't use Webpack, then it's up to you to define a plain-JS boot module that in turn loads
// whatever other files you need (e.g., using some other compiler/bundler API, or maybe just having
// already precompiled to plain JS files on disk).
function loadViaWebpackNoCache(webpackConfigPath, modulePath) {
var ExternalsPlugin = require('webpack-externals-plugin');
var requireFromString = require('require-from-string');
var MemoryFS = require('memory-fs');
var webpack = require('webpack');
// TODO: Consider some general method for checking if you have all the necessary NPM modules installed,
// and if not, giving an error that tells you what command to execute to install the missing ones.
var fs = require('fs');
var ts = requireIfInstalled('ntypescript');
var babelCore = require('babel-core');
var resolveBabelRc = require('babel-loader/lib/resolve-rc'); // If this ever breaks, we can easily scan up the directory hierarchy ourselves
var origJsLoader = require.extensions['.js'];
return new Promise(function(resolve, reject) {
// Load the Webpack config and make alterations needed for loading the output into Node
var webpackConfig = require(webpackConfigPath);
webpackConfig.entry = modulePath;
webpackConfig.target = 'node';
webpackConfig.output = { path: '/', filename: 'webpack-output.js', libraryTarget: 'commonjs' };
function resolveBabelOptions(relativeToFilename) {
var babelRcText = resolveBabelRc(relativeToFilename);
try {
return babelRcText ? JSON.parse(babelRcText) : {};
} catch (ex) {
ex.message = 'Error while parsing babelrc JSON: ' + ex.message;
throw ex;
// In Node, we want anything under /node_modules/ to be loaded natively and not bundled into the output
// (partly because it's faster, but also because otherwise there'd be different instances of modules
// depending on how they were loaded, which could lead to errors)
webpackConfig.plugins = webpackConfig.plugins || [];
webpackConfig.plugins.push(new ExternalsPlugin({ type: 'commonjs', include: /node_modules/ }));
// The CommonsChunkPlugin is not compatible with a CommonJS environment like Node, nor is it needed in that case
webpackConfig.plugins = webpackConfig.plugins.filter(function(plugin) {
return !(plugin instanceof webpack.optimize.CommonsChunkPlugin);
});
// Create a compiler instance that stores its output in memory, then load its output
var compiler = webpack(webpackConfig);
compiler.outputFileSystem = new MemoryFS();
compiler.run(function(err, stats) {
if (err) {
reject(err);
} else {
var fileContent = compiler.outputFileSystem.readFileSync('/webpack-output.js', 'utf8');
var moduleInstance = requireFromString(fileContent);
resolve(moduleInstance);
}
});
});
}
// Ensure we only go through the compile process once per [config, module] pair
var loadViaWebpackPromisesCache = {};
function loadViaWebpack(webpackConfigPath, modulePath, callback) {
var cacheKey = JSON.stringify(webpackConfigPath) + JSON.stringify(modulePath);
if (!(cacheKey in loadViaWebpackPromisesCache)) {
loadViaWebpackPromisesCache[cacheKey] = loadViaWebpackNoCache(webpackConfigPath, modulePath);
}
loadViaWebpackPromisesCache[cacheKey].then(function(result) {
callback(null, result);
}, function(error) {
callback(error);
})
}
function loadViaTypeScript(module, filename) {
if (!ts) {
throw new Error('Can\'t load .ts/.tsx files because the \'ntypescript\' package isn\'t installed.\nModule requested: ' + module);
}
// First perform a minimal transpilation from TS code to ES2015. This is very fast (doesn't involve type checking)
// and is unlikely to need any special compiler options
var src = fs.readFileSync(filename, 'utf8');
var compilerOptions = { jsx: ts.JsxEmit.Preserve, module: ts.ModuleKind.ES2015, target: ts.ScriptTarget.ES6, emitDecoratorMetadata: true };
var es6Code = ts.transpile(src, compilerOptions, 'test.tsx', /* diagnostics */ []);
// Second, process the ES2015 via Babel. We have to do this (instead of going directly from TS to ES5) because
// TypeScript's ES5 output isn't exactly compatible with Node-style CommonJS modules. The main issue is with
// resolving default exports - https://github.com/Microsoft/TypeScript/issues/2719
var es5Code = babelCore.transform(es6Code, resolveBabelOptions(filename)).code;
return module._compile(es5Code, filename);
}
function loadViaBabel(module, filename) {
// Assume that all the app's own code is ES2015+ (optionally with JSX), but that none of the node_modules are.
// The distinction is important because ES2015+ forces strict mode, and it may break ES3/5 if you try to run it in strict
// mode when the developer didn't expect that (e.g., current versions of underscore.js can't be loaded in strict mode).
var useBabel = filename.indexOf('node_modules') < 0;
if (useBabel) {
var transformedFile = babelCore.transformFileSync(filename, resolveBabelOptions(filename));
return module._compile(transformedFile.code, filename);
} else {
return origJsLoader.apply(this, arguments);
}
}
function requireIfInstalled(packageName) {
return isPackageInstalled(packageName) ? require(packageName) : null;
}
function isPackageInstalled(packageName) {
try {
require.resolve(packageName);
return true;
} catch(e) {
return false;
}
}
function register() {
require.extensions['.js'] = loadViaBabel;
require.extensions['.jsx'] = loadViaBabel;
require.extensions['.ts'] = loadViaTypeScript;
require.extensions['.tsx'] = loadViaTypeScript;
};
register();
// -----------------------------------------------------------------------------------------
// Rendering
@@ -85,64 +69,94 @@ var domain = require('domain');
var domainTask = require('domain-task');
var baseUrl = require('domain-task/fetch').baseUrl;
function findBootFunc(bootModulePath, bootModuleExport) {
var resolvedPath = path.resolve(process.cwd(), bootModulePath);
var bootFunc = require(resolvedPath);
if (bootModuleExport) {
bootFunc = bootFunc[bootModuleExport];
} else if (typeof bootFunc !== 'function') {
bootFunc = bootFunc.default; // TypeScript sometimes uses this name for default exports
function findBootModule(bootModule, callback) {
var bootModuleNameFullPath = path.resolve(process.cwd(), bootModule.moduleName);
if (bootModule.webpackConfig) {
var webpackConfigFullPath = path.resolve(process.cwd(), bootModule.webpackConfig);
loadViaWebpack(webpackConfigFullPath, bootModuleNameFullPath, callback);
} else {
callback(null, require(bootModuleNameFullPath));
}
if (typeof bootFunc !== 'function') {
if (bootModuleExport) {
throw new Error('The module at ' + bootModulePath + ' has no function export named ' + bootModuleExport + '.');
} else {
throw new Error('The module at ' + bootModulePath + ' does not export a default function, and you have not specified which export to invoke.');
}
}
return bootFunc;
}
function renderToString(callback, bootModulePath, bootModuleExport, absoluteRequestUrl, requestPathAndQuery) {
var bootFunc = findBootFunc(bootModulePath, bootModuleExport);
// Prepare a promise that will represent the completion of all domain tasks in this execution context.
// The boot code will wait for this before performing its final render.
var domainTaskCompletionPromiseResolve;
var domainTaskCompletionPromise = new Promise(function (resolve, reject) {
domainTaskCompletionPromiseResolve = resolve;
});
var params = {
location: url.parse(requestPathAndQuery),
url: requestPathAndQuery,
absoluteUrl: absoluteRequestUrl,
domainTasks: domainTaskCompletionPromise
};
// Open a new domain that can track all the async tasks involved in the app's execution
domainTask.run(function() {
// Workaround for Node bug where native Promise continuations lose their domain context
// (https://github.com/nodejs/node-v0.x-archive/issues/8648)
bindPromiseContinuationsToDomain(domainTaskCompletionPromise, domain.active);
// Make the base URL available to the 'domain-tasks/fetch' helper within this execution context
baseUrl(absoluteRequestUrl);
// Actually perform the rendering
bootFunc(params).then(function(successResult) {
callback(null, { html: successResult.html, globals: successResult.globals });
}, function(error) {
callback(error, null);
});
}, function allDomainTasksCompleted(error) {
// There are no more ongoing domain tasks (typically data access operations), so we can resolve
// the domain tasks promise which notifies the boot code that it can do its final render.
if (error) {
callback(error, null);
} else {
domainTaskCompletionPromiseResolve();
function findBootFunc(bootModule, callback) {
// First try to load the module (possibly via Webpack)
findBootModule(bootModule, function(findBootModuleError, foundBootModule) {
if (findBootModuleError) {
callback(findBootModuleError);
return;
}
// Now try to pick out the function they want us to invoke
var bootFunc;
if (bootModule.exportName) {
// Explicitly-named export
bootFunc = foundBootModule[bootModule.exportName];
} else if (typeof foundBootModule !== 'function') {
// TypeScript-style default export
bootFunc = foundBootModule.default;
} else {
// Native default export
bootFunc = foundBootModule;
}
// Validate the result
if (typeof bootFunc !== 'function') {
if (bootModule.exportName) {
callback(new Error('The module at ' + bootModule.moduleName + ' has no function export named ' + bootModule.exportName + '.'));
} else {
callback(new Error('The module at ' + bootModule.moduleName + ' does not export a default function, and you have not specified which export to invoke.'));
}
} else {
callback(null, bootFunc);
}
});
}
function renderToString(callback, bootModule, absoluteRequestUrl, requestPathAndQuery) {
findBootFunc(bootModule, function (findBootFuncError, bootFunc) {
if (findBootFuncError) {
callback(findBootFuncError);
return;
}
// Prepare a promise that will represent the completion of all domain tasks in this execution context.
// The boot code will wait for this before performing its final render.
var domainTaskCompletionPromiseResolve;
var domainTaskCompletionPromise = new Promise(function (resolve, reject) {
domainTaskCompletionPromiseResolve = resolve;
});
var params = {
location: url.parse(requestPathAndQuery),
url: requestPathAndQuery,
absoluteUrl: absoluteRequestUrl,
domainTasks: domainTaskCompletionPromise
};
// Open a new domain that can track all the async tasks involved in the app's execution
domainTask.run(function() {
// Workaround for Node bug where native Promise continuations lose their domain context
// (https://github.com/nodejs/node-v0.x-archive/issues/8648)
bindPromiseContinuationsToDomain(domainTaskCompletionPromise, domain.active);
// Make the base URL available to the 'domain-tasks/fetch' helper within this execution context
baseUrl(absoluteRequestUrl);
// Actually perform the rendering
bootFunc(params).then(function(successResult) {
callback(null, { html: successResult.html, globals: successResult.globals });
}, function(error) {
callback(error, null);
});
}, function allDomainTasksCompleted(error) {
// There are no more ongoing domain tasks (typically data access operations), so we can resolve
// the domain tasks promise which notifies the boot code that it can do its final render.
if (error) {
callback(error, null);
} else {
domainTaskCompletionPromiseResolve();
}
});
});
}

12
src/Microsoft.AspNet.SpaServices/Prerendering/PrerenderTagHelper.cs
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@@ -17,12 +17,16 @@ namespace Microsoft.AspNet.SpaServices.Prerendering
const string PrerenderModuleAttributeName = "asp-prerender-module";
const string PrerenderExportAttributeName = "asp-prerender-export";
const string PrerenderWebpackConfigAttributeName = "asp-prerender-webpack-config";
[HtmlAttributeName(PrerenderModuleAttributeName)]
public string ModuleName { get; set; }
[HtmlAttributeName(PrerenderExportAttributeName)]
public string ExportName { get; set; }
[HtmlAttributeName(PrerenderWebpackConfigAttributeName)]
public string WebpackConfigPath { get; set; }
private IHttpContextAccessor contextAccessor;
private INodeServices nodeServices;
@@ -48,13 +52,15 @@ namespace Microsoft.AspNet.SpaServices.Prerendering
var request = this.contextAccessor.HttpContext.Request;
var result = await Prerenderer.RenderToString(
nodeServices: this.nodeServices,
componentModuleName: this.ModuleName,
componentExportName: this.ExportName,
bootModule: new JavaScriptModuleExport(this.ModuleName) {
exportName = this.ExportName,
webpackConfig = this.WebpackConfigPath
},
requestAbsoluteUrl: UriHelper.GetEncodedUrl(this.contextAccessor.HttpContext.Request),
requestPathAndQuery: request.Path + request.QueryString.Value);
output.Content.SetHtmlContent(result.Html);
// Also attach any specific globals to the 'window' object. This is useful for transferring
// Also attach any specified globals to the 'window' object. This is useful for transferring
// general state between server and client.
if (result.Globals != null) {
var stringBuilder = new StringBuilder();

19
src/Microsoft.AspNet.SpaServices/Prerendering/Prerenderer.cs
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@@ -16,12 +16,21 @@ namespace Microsoft.AspNet.SpaServices.Prerendering
});
}
public static async Task<RenderToStringResult> RenderToString(INodeServices nodeServices, string componentModuleName, string componentExportName, string requestAbsoluteUrl, string requestPathAndQuery) {
public static async Task<RenderToStringResult> RenderToString(INodeServices nodeServices, JavaScriptModuleExport bootModule, string requestAbsoluteUrl, string requestPathAndQuery) {
return await nodeServices.InvokeExport<RenderToStringResult>(nodeScript.Value.FileName, "renderToString",
/* bootModulePath */ componentModuleName,
/* bootModuleExport */ componentExportName,
/* absoluteRequestUrl */ requestAbsoluteUrl,
/* requestPathAndQuery */ requestPathAndQuery);
bootModule,
requestAbsoluteUrl,
requestPathAndQuery);
}
}
public class JavaScriptModuleExport {
public string moduleName { get; private set; }
public string exportName { get; set; }
public string webpackConfig { get; set; }
public JavaScriptModuleExport(string moduleName) {
this.moduleName = moduleName;
}
}

34
templates/Angular2Spa/ClientApp/boot-server.ts
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@@ -4,29 +4,19 @@ import * as ngRouter from 'angular2/router';
import * as ngUniversal from 'angular2-universal-preview';
import { BASE_URL } from 'angular2-universal-preview/dist/server/src/http/node_http';
import * as ngUniversalRender from 'angular2-universal-preview/dist/server/src/render';
import { App } from './components/app/app';
// TODO: Make this ugly code go away, e.g., by somehow loading via Webpack
function loadAsString(module, filename) {
module.exports = require('fs').readFileSync(filename, 'utf8');
}
(require as any).extensions['.html'] = loadAsString;
(require as any).extensions['.css'] = loadAsString;
let App: any = require('./components/app/app').App;
export default function (params: any): Promise<{ html: string, globals?: any }> {
const serverBindings = [
ngRouter.ROUTER_BINDINGS,
ngUniversal.HTTP_PROVIDERS,
ngCore.provide(BASE_URL, { useValue: params.absoluteUrl }),
ngCore.provide(ngUniversal.REQUEST_URL, { useValue: params.url }),
ngCore.provide(ngRouter.APP_BASE_HREF, { useValue: '/' }),
ngUniversal.SERVER_LOCATION_PROVIDERS
];
export default function (params: any): Promise<{ html: string }> {
return new Promise<{ html: string, globals: { [key: string]: any } }>((resolve, reject) => {
const serverBindings = [
ngRouter.ROUTER_BINDINGS,
ngUniversal.HTTP_PROVIDERS,
ngCore.provide(BASE_URL, { useValue: params.absoluteUrl }),
ngCore.provide(ngUniversal.REQUEST_URL, { useValue: params.url }),
ngCore.provide(ngRouter.APP_BASE_HREF, { useValue: '/' }),
ngUniversal.SERVER_LOCATION_PROVIDERS
];
ngUniversalRender.renderToString(App, serverBindings).then(
html => resolve({ html, globals: {} }),
reject // Also propagate any errors back into the host application
);
return ngUniversalRender.renderToString(App, serverBindings).then(html => {
return { html, globals: {}};
});
}

3
templates/Angular2Spa/Views/Home/Index.cshtml
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@@ -2,7 +2,8 @@
ViewData["Title"] = "Home Page";
}
<app asp-prerender-module="ClientApp/boot-server">Loading...</app>
<app asp-prerender-module="ClientApp/boot-server"
asp-prerender-webpack-config="webpack.config.js">Loading...</app>
@section scripts {
<script src="~/dist/main.js" asp-append-version="true"></script>

2
templates/Angular2Spa/package.json
View File

@@ -35,7 +35,9 @@
"parse5": "^1.5.1",
"preboot": "^1.1.3",
"reflect-metadata": "^0.1.2",
"require-from-string": "^1.1.0",
"rxjs": "^5.0.0-beta.2",
"webpack-externals-plugin": "^1.0.0",
"zone.js": "^0.5.15"
}
}