webpack/lib/dependencies/RequireEnsureDependenciesBlockParserPlugin.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jade, coffee, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
var AbstractPlugin = require("../AbstractPlugin");
var RequireEnsureDependenciesBlock = require("./RequireEnsureDependenciesBlock");
var RequireEnsureItemDependency = require("./RequireEnsureItemDependency");
var getFunctionExpression = require("./getFunctionExpression");

module.exports = AbstractPlugin.create({
	"call require.ensure": function(expr) {
		var chunkName = null, chunkNameRange = null;
		switch(expr.arguments.length) {
		case 3:
			var chunkNameExpr = this.evaluateExpression(expr.arguments[2]);
			if(!chunkNameExpr.isString()) return;
			chunkNameRange = chunkNameExpr.range;
			chunkName = chunkNameExpr.string;
			// fall through
		case 2:
			var dependencies = null;
			var dependenciesExpr = this.evaluateExpression(expr.arguments[0]);
			if(!dependenciesExpr.isArray()) return;
			var fnExpressionArg = expr.arguments[1];
			var fnExpression = getFunctionExpression(fnExpressionArg);

			if(fnExpression) {
				this.walkExpressions(fnExpression.expressions);
			}

			var dep = new RequireEnsureDependenciesBlock(expr, fnExpression ? fnExpression.fn : fnExpressionArg, chunkName, chunkNameRange, this.state.module, expr.loc);
			var old = this.state.current;
			this.state.current = dep;
			try {
				var failed = false;
				this.inScope([], function() {
					dependenciesExpr.items.forEach(function(ee) {
						if(ee.isString()) {
							var edep = new RequireEnsureItemDependency(ee.string, ee.range);
							edep.loc = dep.loc;
							dep.addDependency(edep);
						} else {
							failed = true;
						}
					});
				});
				if(failed) {
					return;
				}
				if(fnExpression) {
					if(fnExpression.fn.body.type === "BlockStatement")
						this.walkStatement(fnExpression.fn.body);
					else
						this.walkExpression(fnExpression.fn.body);
				}
				old.addBlock(dep);
			} finally {
				this.state.current = old;
			}
			if(!fnExpression) {
				this.walkExpression(fnExpressionArg);
			}
			return true;
		}
	}
});