Embedded JavaScript templates
[![Known Vulnerabilities](https://snyk.io/test/npm/ejs/badge.svg?style=flat)](https://snyk.io/test/npm/ejs) ============================= ## Security Security professionals, before reporting any security issues, please reference the SECURITY.md in this project, in particular, the following: "EJS is effectively a JavaScript runtime. Its entire job is to execute JavaScript. If you run the EJS render method without checking the inputs yourself, you are responsible for the results." In short, DO NOT submit 'vulnerabilities' that include this snippet of code: ```javascript app.get('/', (req, res) => { res.render('index', req.query); }); ``` ## Installation ```bash $ npm install ejs ``` ## Features * Control flow with `<% %>` * Escaped output with `<%= %>` (escape function configurable) * Unescaped raw output with `<%- %>` * Newline-trim mode ('newline slurping') with `-%>` ending tag * Whitespace-trim mode (slurp all whitespace) for control flow with `<%_ _%>` * Custom delimiters (e.g. `[? ?]` instead of `<% %>`) * Includes * Client-side support * Static caching of intermediate JavaScript * Static caching of templates * Complies with the [Express](http://expressjs.com) view system ## Example ```ejs <% if (user) { %>

<%= user.name %>

<% } %> ``` Try EJS online at: https://ionicabizau.github.io/ejs-playground/. ## Basic usage ```javascript let template = ejs.compile(str, options); template(data); // => Rendered HTML string ejs.render(str, data, options); // => Rendered HTML string ejs.renderFile(filename, data, options, function(err, str){ // str => Rendered HTML string }); ``` It is also possible to use `ejs.render(dataAndOptions);` where you pass everything in a single object. In that case, you'll end up with local variables for all the passed options. However, be aware that your code could break if we add an option with the same name as one of your data object's properties. Therefore, we do not recommend using this shortcut. ### Important You should never give end-users unfettered access to the EJS render method, If you do so you are using EJS in an inherently un-secure way. ### Options - `cache` Compiled functions are cached, requires `filename` - `filename` The name of the file being rendered. Not required if you are using `renderFile()`. Used by `cache` to key caches, and for includes. - `root` Set template root(s) for includes with an absolute path (e.g, /file.ejs). Can be array to try to resolve include from multiple directories. - `views` An array of paths to use when resolving includes with relative paths. - `context` Function execution context - `compileDebug` When `false` no debug instrumentation is compiled - `client` When `true`, compiles a function that can be rendered in the browser without needing to load the EJS Runtime ([ejs.min.js](https://github.com/mde/ejs/releases/latest)). - `delimiter` Character to use for inner delimiter, by default '%' - `openDelimiter` Character to use for opening delimiter, by default '<' - `closeDelimiter` Character to use for closing delimiter, by default '>' - `debug` Outputs generated function body - `strict` When set to `true`, generated function is in strict mode - `_with` Whether or not to use `with() {}` constructs. If `false` then the locals will be stored in the `locals` object. Set to `false` in strict mode. - `destructuredLocals` An array of local variables that are always destructured from the locals object, available even in strict mode. - `localsName` Name to use for the object storing local variables when not using `with` Defaults to `locals` - `rmWhitespace` Remove all safe-to-remove whitespace, including leading and trailing whitespace. It also enables a safer version of `-%>` line slurping for all scriptlet tags (it does not strip new lines of tags in the middle of a line). - `escape` The escaping function used with `<%=` construct. It is used in rendering and is `.toString()`ed in the generation of client functions. (By default escapes XML). - `outputFunctionName` Set to a string (e.g., 'echo' or 'print') for a function to print output inside scriptlet tags. - `async` When `true`, EJS will use an async function for rendering. (Depends on async/await support in the JS runtime. - `includer` Custom function to handle EJS includes, receives `(originalPath, parsedPath)` parameters, where `originalPath` is the path in include as-is and `parsedPath` is the previously resolved path. Should return an object `{ filename, template }`, you may return only one of the properties, where `filename` is the final parsed path and `template` is the included content. This project uses [JSDoc](http://usejsdoc.org/). For the full public API documentation, clone the repository and run `jake doc`. This will run JSDoc with the proper options and output the documentation to `out/`. If you want the both the public & private API docs, run `jake devdoc` instead. ### Tags - `<%` 'Scriptlet' tag, for control-flow, no output - `<%_` 'Whitespace Slurping' Scriptlet tag, strips all whitespace before it - `<%=` Outputs the value into the template (escaped) - `<%-` Outputs the unescaped value into the template - `<%#` Comment tag, no execution, no output - `<%%` Outputs a literal '<%' - `%%>` Outputs a literal '%>' - `%>` Plain ending tag - `-%>` Trim-mode ('newline slurp') tag, trims following newline - `_%>` 'Whitespace Slurping' ending tag, removes all whitespace after it For the full syntax documentation, please see [docs/syntax.md](https://github.com/mde/ejs/blob/master/docs/syntax.md). ### Includes Includes either have to be an absolute path, or, if not, are assumed as relative to the template with the `include` call. For example if you are including `./views/user/show.ejs` from `./views/users.ejs` you would use `<%- include('user/show') %>`. You must specify the `filename` option for the template with the `include` call unless you are using `renderFile()`. You'll likely want to use the raw output tag (`<%-`) with your include to avoid double-escaping the HTML output. ```ejs ``` Includes are inserted at runtime, so you can use variables for the path in the `include` call (for example `<%- include(somePath) %>`). Variables in your top-level data object are available to all your includes, but local variables need to be passed down. NOTE: Include preprocessor directives (`<% include user/show %>`) are not supported in v3.0+. ## Custom delimiters Custom delimiters can be applied on a per-template basis, or globally: ```javascript let ejs = require('ejs'), users = ['geddy', 'neil', 'alex']; // Just one template ejs.render('

[?= users.join(" | "); ?]

', {users: users}, {delimiter: '?', openDelimiter: '[', closeDelimiter: ']'}); // => '

geddy | neil | alex

' // Or globally ejs.delimiter = '?'; ejs.openDelimiter = '['; ejs.closeDelimiter = ']'; ejs.render('

[?= users.join(" | "); ?]

', {users: users}); // => '

geddy | neil | alex

' ``` ### Caching EJS ships with a basic in-process cache for caching the intermediate JavaScript functions used to render templates. It's easy to plug in LRU caching using Node's `lru-cache` library: ```javascript let ejs = require('ejs'), LRU = require('lru-cache'); ejs.cache = LRU(100); // LRU cache with 100-item limit ``` If you want to clear the EJS cache, call `ejs.clearCache`. If you're using the LRU cache and need a different limit, simple reset `ejs.cache` to a new instance of the LRU. ### Custom file loader The default file loader is `fs.readFileSync`, if you want to customize it, you can set ejs.fileLoader. ```javascript let ejs = require('ejs'); let myFileLoad = function (filePath) { return 'myFileLoad: ' + fs.readFileSync(filePath); }; ejs.fileLoader = myFileLoad; ``` With this feature, you can preprocess the template before reading it. ### Layouts EJS does not specifically support blocks, but layouts can be implemented by including headers and footers, like so: ```ejs <%- include('header') -%>

Title

My page

<%- include('footer') -%> ``` ## Client-side support Go to the [Latest Release](https://github.com/mde/ejs/releases/latest), download `./ejs.js` or `./ejs.min.js`. Alternately, you can compile it yourself by cloning the repository and running `jake build` (or `$(npm bin)/jake build` if jake is not installed globally). Include one of these files on your page, and `ejs` should be available globally. ### Example ```html
``` ### Caveats Most of EJS will work as expected; however, there are a few things to note: 1. Obviously, since you do not have access to the filesystem, `ejs.renderFile()` won't work. 2. For the same reason, `include`s do not work unless you use an `include callback`. Here is an example: ```javascript let str = "Hello <%= include('file', {person: 'John'}); %>", fn = ejs.compile(str, {client: true}); fn(data, null, function(path, d){ // include callback // path -> 'file' // d -> {person: 'John'} // Put your code here // Return the contents of file as a string }); // returns rendered string ``` See the [examples folder](https://github.com/mde/ejs/tree/master/examples) for more details. ## CLI EJS ships with a full-featured CLI. Options are similar to those used in JavaScript code: - `-o / --output-file FILE` Write the rendered output to FILE rather than stdout. - `-f / --data-file FILE` Must be JSON-formatted. Use parsed input from FILE as data for rendering. - `-i / --data-input STRING` Must be JSON-formatted and URI-encoded. Use parsed input from STRING as data for rendering. - `-m / --delimiter CHARACTER` Use CHARACTER with angle brackets for open/close (defaults to %). - `-p / --open-delimiter CHARACTER` Use CHARACTER instead of left angle bracket to open. - `-c / --close-delimiter CHARACTER` Use CHARACTER instead of right angle bracket to close. - `-s / --strict` When set to `true`, generated function is in strict mode - `-n / --no-with` Use 'locals' object for vars rather than using `with` (implies --strict). - `-l / --locals-name` Name to use for the object storing local variables when not using `with`. - `-w / --rm-whitespace` Remove all safe-to-remove whitespace, including leading and trailing whitespace. - `-d / --debug` Outputs generated function body - `-h / --help` Display this help message. - `-V/v / --version` Display the EJS version. Here are some examples of usage: ```shell $ ejs -p [ -c ] ./template_file.ejs -o ./output.html $ ejs ./test/fixtures/user.ejs name=Lerxst $ ejs -n -l _ ./some_template.ejs -f ./data_file.json ``` ### Data input There is a variety of ways to pass the CLI data for rendering. Stdin: ```shell $ ./test/fixtures/user_data.json | ejs ./test/fixtures/user.ejs $ ejs ./test/fixtures/user.ejs < test/fixtures/user_data.json ``` A data file: ```shell $ ejs ./test/fixtures/user.ejs -f ./user_data.json ``` A command-line option (must be URI-encoded): ```shell ./bin/cli.js -i %7B%22name%22%3A%20%22foo%22%7D ./test/fixtures/user.ejs ``` Or, passing values directly at the end of the invocation: ```shell ./bin/cli.js -m $ ./test/fixtures/user.ejs name=foo ``` ### Output The CLI by default send output to stdout, but you can use the `-o` or `--output-file` flag to specify a target file to send the output to. ## IDE Integration with Syntax Highlighting VSCode:Javascript EJS by *DigitalBrainstem* ## Related projects There are a number of implementations of EJS: * TJ's implementation, the v1 of this library: https://github.com/tj/ejs * EJS Embedded JavaScript Framework on Google Code: https://code.google.com/p/embeddedjavascript/ * Sam Stephenson's Ruby implementation: https://rubygems.org/gems/ejs * Erubis, an ERB implementation which also runs JavaScript: http://www.kuwata-lab.com/erubis/users-guide.04.html#lang-javascript * DigitalBrainstem EJS Language support: https://github.com/Digitalbrainstem/ejs-grammar ## License Licensed under the Apache License, Version 2.0 () - - - EJS Embedded JavaScript templates copyright 2112 mde@fleegix.org.