Vue编译器源码分析compileToFunctions作用详解

var ref = compileToFunctions(template, {
	shouldDecodeNewlines: shouldDecodeNewlines,
	shouldDecodeNewlinesForhref: shouldDecodeNewlinesForhref,
	delimiters: options.delimiters,
	comments: options.comments
}, this);

// check whether current browser encodes a char inside attribute values
var div;
function getShouldDecode(href) {
	div = div || document.createElement('div');
	div.innerHTML = href ? "<a href=\"\n\"/>" : "<div a=\"\n\"/>";
	return div.innerHTML.indexOf('&#10;') > 0
}
// #3663: IE encodes newlines inside attribute values while other browsers don't
var shouldDecodeNewlines = inBrowser ? getShouldDecode(false) : false;
// #6828: chrome encodes content in a[href]
var shouldDecodeNewlinesForhref = inBrowser ? getShouldDecode(true) : false;

function createCompileToFunctionFn(compile) {
	var cache = Object.create(null);
	return function compileToFunctions(
		template,
		options,
		vm
	) {
		options = extend({}, options);
		var warn$$1 = options.warn || warn;
		delete options.warn;
		/* istanbul ignore if */
		{
			// detect possible CSP restriction
			try {
				new Function('return 1');
			} catch (e) {
				if (e.toString().match(/unsafe-eval|CSP/)) {
					warn$$1(
						'It seems you are using the standalone build of Vue.js in an ' +
						'environment with Content Security Policy that prohibits unsafe-eval. ' +
						'The template compiler cannot work in this environment. Consider ' +
						'relaxing the policy to allow unsafe-eval or pre-compiling your ' +
						'templates into render functions.'
					);
				}
			}
		}
		// check cache
		var key = options.delimiters ?
			String(options.delimiters) + template :
			template;
		if (cache[key]) {
			return cache[key]
		}
		// compile
		var compiled = compile(template, options);
		// check compilation errors/tips
		{
			if (compiled.errors && compiled.errors.length) {
				warn$$1(
					"Error compiling template:\n\n" + template + "\n\n" +
					compiled.errors.map(function(e) {
						return ("- " + e);
					}).join('\n') + '\n',
					vm
				);
			}
			if (compiled.tips && compiled.tips.length) {
				compiled.tips.forEach(function(msg) {
					return tip(msg, vm);
				});
			}
		}
		// turn code into functions
		var res = {};
		var fnGenErrors = [];
		res.render = createFunction(compiled.render, fnGenErrors);
		res.staticRenderFns = compiled.staticRenderFns.map(function(code) {
			return createFunction(code, fnGenErrors)
		});
		// check function generation errors.
		// this should only happen if there is a bug in the compiler itself.
		// mostly for codegen development use
		/* istanbul ignore if */
		{
			if ((!compiled.errors || !compiled.errors.length) && fnGenErrors.length) {
				warn$$1(
					"Failed to generate render function:\n\n" +
					fnGenErrors.map(function(ref) {
						var err = ref.err;
						var code = ref.code;
						return ((err.toString()) + " in\n\n" + code + "\n");
					}).join('\n'),
					vm
				);
			}
		}
		return (cache[key] = res)
	}
}

options = extend({}, options);
var warn$$1 = options.warn || warn;
delete options.warn;

// detect possible CSP restriction
try {
	new Function('return 1');
} catch (e) {
	if (e.toString().match(/unsafe-eval|CSP/)) {
		warn$$1(
			'It seems you are using the standalone build of Vue.js in an ' +
			'environment with Content Security Policy that prohibits unsafe-eval. ' +
			'The template compiler cannot work in this environment. Consider ' +
			'relaxing the policy to allow unsafe-eval or pre-compiling your ' +
			'templates into render functions.'
		);
	}
}

var key = options.delimiters ?
	String(options.delimiters) + template :
	template;
if (cache[key]) {
	return cache[key]
}

return (cache[key] = res)

// compile
var compiled = compile(template, options);
// check compilation errors/tips
if (compiled.errors && compiled.errors.length) {
	warn$$1(
		"Error compiling template:\n\n" + template + "\n\n" +
		compiled.errors.map(function(e) {
			return ("- " + e);
		}).join('\n') + '\n',
		vm
	);
   }
if (compiled.tips && compiled.tips.length) {
	compiled.tips.forEach(function(msg) {
		return tip(msg, vm);
	});
   }
}

// turn code into functions
var res = {};
var fnGenErrors = [];
res.render = createFunction(compiled.render, fnGenErrors);
res.staticRenderFns = compiled.staticRenderFns.map(function(code) {
	return createFunction(code, fnGenErrors)
});

function createFunction(code, errors) {
	try {
		return new Function(code)
	} catch (err) {
		errors.push({
			err: err,
			code: code
		});
		return noop
	}
}

res.staticRenderFns = compiled.staticRenderFns.map(function(code) {
	return createFunction(code, fnGenErrors)
});

// check function generation errors.
// this should only happen if there is a bug in the compiler itself.
// mostly for codegen development use
/* istanbul ignore if */
if ((!compiled.errors || !compiled.errors.length) && fnGenErrors.length) {
	warn$$1(
		"Failed to generate render function:\n\n" +
		fnGenErrors.map(function(ref) {
			var err = ref.err;
			var code = ref.code;
			return ((err.toString()) + " in\n\n" + code + "\n");
		}).join('\n'),
		vm
	);
}
return (cache[key] = res)