Luigi Template ============== Overview -------- Simple JavaScript string templating library inspired by [Unix pipes][pipe]. Features: * Filters via piping, with common filters built-in. * Useful built-in filters. * Template caching. * Small: Less than 4k minified (see `luigi-template.min.js`), * Stand-alone: No external dependencies (no jQuery, etc), * Compatible: Works in browsers as old as IE9 * MIT-licensed Installation ------------ Minify `luigi-template.js` using your minifier of choice, and drop it into your source tree. I like [jsmin][], personally: jsmin luigi-template.js > luigi-template.min.js *Note:* If you are upgrading from a pre-0.5.0 version of Luigi Template, be sure to include `luigi-compat.js` as well. See the *Changes in 0.5.0* section below for details. Usage ----- A minimal template: // create template var t = new Luigi.Template('hello %{name}'); // run template, print result to console console.log(t.run({ name: 'Paul', })); // prints "hello Paul" If you have a template that you only need to run one time, you can use the `Luigi.run()` singleton to run it, like this: // create and run template in one shot var r = Luigi.run('hello %{name}', { name: 'Paul', }); // print result to console console.log(r); // prints "hello Paul" Templates parameters can be modified by filters. Filters are applied to a parameter value by appending a `|` (pipe) character, followed by the filter name. Here is the template from above, with the name value HTML-escaped using a built-in filter: // create template that prints hello and the HTML-escaped name var t = new Luigi.Template('hello %{name | h}'); // run template, print result to console console.log(t.run({ name: '', })); // prints "hello <Paul>" The built-in templates are: * `uc`: Upper-case string value. * `lc`: Lower-case string value. * `s`: Pluralize a value by returning `""` if the value is 1, and `"s"` otherwise. * `length`: Get the length of an array. * `trim`: Trim leading and trailing whitespace from a string. * `h`: HTML-escape a string value. * `u`: URL-escape a string value. * `json`: JSON-encode a value. You can create your own custom filters, too. The easiest way to create your own custom filter is to add it to the set of global filters (`Luigi.FILTERS`), like so: // add global template filter Luigi.FILTERS.barify = function(s) { return 'bar-' + s + '-bar'; }; // create template that uses custom global filter var t = new Luigi.Template('hello %{name | barify | h}'); // run template, print result to console console.log(t.run({ name: '', })); // prints "hello bar-<Paul>-bar" You can also create a custom filter and limit it to a particular template by passing a custom filter hash as the second parameter to the `Luigi.Template` constructor, like this: // create template with custom template-specific filter var t = new Luigi.Template('hello %{name | barify | h}', { barify: function(s) { return 'bar-' + s + '-bar'; }, }); // run template, print result to console console.log(t.run({ name: '', })); // prints "hello bar-<Paul>-bar" You can pass arguments to your custom filters. Here's an example: // create template with custom template-specific filter named // "wrap", which wraps the value in the given filter parameters var t = new Luigi.Template('hello %{name | wrap head tail | h}', { wrap: function(s, args) { if (args.length == 2) { return [args[0], s, args[1]].join('-'; } else if (args.length == 1) { return [args[0], s, args[0]].join('-'); } else { return s; } }, }); // run template, print result to console console.log(t.run({ name: '', })); // prints "hello head-<Paul>-tail" If you have a lot of separate templates, or a few large templates, then it's a good idea to use a template cache. A template cache will create templates as they are needed (also known as "lazy initialization"), so the script loads quickly. A template cache also caches instantiated (that is, created) templates for future use, so that running a template from the cache is fast too. Here's how you create a template cache: // create template cache with a single template var cache = Luigi.cache({ hello: 'hello %{name | uc | h}' }); // run template, print result to console console.log(cache.run('hello', { name: '', })); // prints "hello <PAUL%gt;" Template caches use their own set of custom filters by passing a custom filter hash when creating a template cache: // create template cache with a custom filter named "reverse" var cache = Luigi.cache({ hello: 'hello %{name | uc | reverse | h}' }, { reverse: function(s) { var cs = (s || '').split(''); cs.reverse(); return cs.join(''); }, }); // run template, print result to console console.log(cache.run('hello', { name: '', })); // prints "hello %gt;LUAP<" A template cache is also a convenient way to group all of the templates in a script together: // add global filter named "reverse" Luigi.FILTERS.reverse = function(s) { var cs = (s || '').split(''); cs.reverse(); return cs.join(''); }; // create template cache var TEMPLATES = Luigi.cache({ upper: 'hello %{name | uc | h}', reverse: 'hello %{name | reverse | h}', }); // run the upper and reverse templates above and populate // the elements #upper and #reverse with their respective // result ['upper', 'reverse'].forEach(function(id) { getElementByid(id).innerHTML = TEMPLATES.run(id, { name: '', }); }); Documentation ------------- Usage documentation is available in the *Usage* section above, and API documentation is available online at the following URL: [https://pablotron.github.io/luigi-template/][api-docs] You can also generate the documentation yourself using [jsdoc][]. Tests ----- This `test/` directory contains the test suite for the JavaScript implementation of [Luigi Template][], written in [Mocha][] and [Chai]. To run the test suite, load `test/test.html` in a browser. Changes in 0.5.0 ---------------- Version 0.5.0 of Luigi Template changes the namespace from `LuigiTemplate` to `Luigi`, which has the following effects: * old (0.4.x): `new LuigiTemplate(...)`, new (0.5): `new Luigi.Template(...)` * old (0.4.x): `LuigiTemplate.run(...)`, new: (0.5): `Luigi.run(...)` * old (0.4.x): `LuigiTemplate.VERSION`, new (0.5): `Luigi.VERSION` * old (0.4.x): `LuigiTemplate.FILTERS`, new: (0.5): `Luigi.FILTERS` * old (0.4.x): `new LuigiTemplate.Cache(...)`, new: (0.5): `Luigi.cache(...)` (recommended) or `new Luigi.Cache(...)` If you have an existing system that you cannot make changes to, you can include `luigi-compat.js` as a compatibility shim. Tests for the compatibility shim are available in `test/compat/`. *Note:* The compatibility shim will disappear in a future release. Author ------ Paul Duncan ([pabs@pablotron.org][me])
[https://pablotron.org/][me-web] License ------- Copyright 2014-2018 Paul Duncan ([pabs@pablotron.org][me]) Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. [pipe]: https://en.wikipedia.org/wiki/Pipeline_(Unix) [jsmin]: https://www.crockford.com/javascript/jsmin.html [Luigi Template]: https://github.com/pablotron/luigi-template [me]: mailto:pabs@pablotron.org [me-web]: https://pablotron.org/ [Mocha]: https://mochajs.org/ [Chai]: http://www.chaijs.com/ [jsdoc]: http://usejsdoc.org/ [api-docs]: https://pablotron.github.io/luigi-template/