Closure Tools for Bazel

Overview

These rules define targets for JavaScript, stylesheets, and templates that will be compiled with the Closure Tools toolchain.

• closure_js_binary
• closure_js_library
• closure_stylesheet_library
• closure_template_library

Setup

The rules defined in //tools/build_rules/closure/closure.WORKSPACE must be copied into your WORKSPACE file before using these rules. These rules define the locations of the various Closure Tools binaries and the Closure Library.

Usage

Suppose we are building a web application with template, stylesheet, and JavaScript files: hello.soy, hello.gss, and hello.js.

hello.soy

{namespace hello.templates autoescape="strict"}

/**
 * Renders an element containing the text "hello".
 */
{template .hello}
  <div class="{css hello-container}">Hello.</div>
{/template}

hello.gss

.hello-container {
  color: red;
  font-weight: bold;
}

hello.js

goog.provide('hello');

goog.require('goog.soy');
goog.require('hello.templates');

goog.soy.renderElement(document.body, hello.templates.hello);

We can create a BUILD file to compile these and produce two files:

• hello_combined.css
• hello_combined.js

BUILD

load("/tools/build_rules/closure/closure_js_binary", "closure_js_binary")
load("/tools/build_rules/closure/closure_js_library", "closure_js_library")
load("/tools/build_rules/closure/closure_stylesheet_library", "closure_stylesheet_library")
load("/tools/build_rules/closure/closure_template_library", "closure_template_library")

closure_js_binary(
    name = "hello",
    main = "hello",
    deps = [":hello_lib"],
)

closure_js_library(
    name = "hello_lib",
    srcs = ["hello.js"],
    deps = [
        "@closure_library//:closure_library",
        "@closure_templates//:closure_templates_js",
        ":hello_css",
        ":hello_soy",
    ]
)

closure_stylesheet_library(
    name = "hello_css",
    srcs = ["hello.gss"],
    deps = ["@closure_library//:closure_library_css"],
)

closure_template_library(
    name = "hello_soy",
    srcs = ["hello.soy"],
)

Known Issues

The version of the Closure Templates compiler that is used will emit warnings about protected property access and about a missing enum value. These issues have been fixed in the source, but are not yet available as a downloadable archive. These warnings are safe to ignore.

You may define a new_local_repository target if you wish to check out the source from Github yourself. Otherwise you may wish to wait until the Closure tools are available as Bazel workspaces. e.g.

new_local_repository(
    name = "closure_templates",
    build_file = "tools/build_rules/closure/closure_templates.BUILD",
    path = "/home/user/src/github/google/closure-templates/target",
)