EJSQL

Embedded JavaScript templates for SQL

Installation

$ npm install ejsql

Features

• Control flow with <% %>
• Value output with <%= %>
• Table name or column name output with <%- %>
• Array value output with <%~ %>
• Newline-trim mode ('newline slurping') with -%> ending tag
• Whitespace-trim mode (slurp all whitespace) for control flow with <%_ _%>
• Custom delimiters (e.g., use <? ?> instead of <% %>)
• Includes
• Static caching of intermediate JavaScript
• Static caching of templates

Example

SELECT * FROM user
<% if (user) { %>
  WHERE id = <%= user.id %>
<% } %>

Usage

let template = ejsql.compile(str, options);
template(data);
// => Rendered SQL string

ejsql.render(str, data, options);
// => Rendered SQL string

ejsql.renderFile(filename, data, options, function(err, str){
    // str => Rendered SQL string
});

It is also possible to use ejsql.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.

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 project root for includes with an absolute path (/file.ejs).
• context Function execution context
• compileDebug When false no debug instrumentation is compiled
• delimiter Character to use with angle brackets for open/close
• debug Output 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.
• 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).
• async When true, EJSQL will use an async function for rendering. (Depends on async/await support in the JS runtime.

This project uses JSDoc. For the full public API documentation, clone the repository and run npm run 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 npm run 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
• <%- Outputs the table name or column name into the template
• <%~ Outputs the array 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.

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().

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 still supported.

Custom delimiters

Custom delimiters can be applied on a per-template basis, or globally:

let ejsql = require('ejsql'),
    users = ['geddy', 'neil', 'alex'];

// Just one template
ejsql.render('<?= users.join(" | "); ?>', {users: users}, {delimiter: '?'});
// => 'geddy | neil | alex'

// Or globally
ejsql.delimiter = '$';
ejsql.render('<$= users.join(" | "); $>', {users: users});
// => 'geddy | neil | alex'

Caching

EJSQL 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:

let ejsql = require('ejsql'),
    LRU = require('lru-cache');
ejsql.cache = LRU(100); // LRU cache with 100-item limit

If you want to clear the EJSQL cache, call ejsql.clearCache. If you're using the LRU cache and need a different limit, simple reset ejsql.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 ejsql.fileLoader.

let ejsql = require('ejsql');
let myFileLoad = function (filePath) {
  return 'myFileLoad: ' + fs.readFileSync(filePath);
};

ejsql.fileLoader = myFileLoad;

With this feature, you can preprocess the template before reading it.

Layouts

EJSQL does not specifically support blocks, but layouts can be implemented by including headers and footers, like so:

<%- include('select') -%>
 WHERE user.id = <%= userid %>
<%- include('orderby') -%>

Caveats

Most of EJSQL will work as expected; however, there are a few things to note:

1. Obviously, since you do not have access to the filesystem, ejsql.renderFile() won't work.
2. For the same reason, includes do not work unless you use an include callback.

Related projects

There are a number of implementations of EJSQL:

• The v2 of EJS that EJSQL is forked from: https://github.com/mde/ejs
• TJ's implementation, the v1 of this library: https://github.com/tj/ejs
• Jupiter Consulting's EJS: http://www.embeddedjs.com/
• 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 (http://www.apache.org/licenses/LICENSE-2.0)

EJSQL Embedded JavaScript templates for SQL copyright 2018 motojouya.