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parse.js
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2009 lines (1840 loc) · 64.9 KB
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'use strict';
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Any commits to this file should be reviewed with security in mind. *
* Changes to this file can potentially create security vulnerabilities. *
* An approval from 2 Core members with history of modifying *
* this file is required. *
* *
* Does the change somehow allow for arbitrary javascript to be executed? *
* Or allows for someone to change the prototype of built-in objects? *
* Or gives undesired access to variables likes document or window? *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
var $parseMinErr = minErr('$parse');
// Sandboxing Angular Expressions
// ------------------------------
// Angular expressions are generally considered safe because these expressions only have direct
// access to `$scope` and locals. However, one can obtain the ability to execute arbitrary JS code by
// obtaining a reference to native JS functions such as the Function constructor.
//
// As an example, consider the following Angular expression:
//
// {}.toString.constructor('alert("evil JS code")')
//
// This sandboxing technique is not perfect and doesn't aim to be. The goal is to prevent exploits
// against the expression language, but not to prevent exploits that were enabled by exposing
// sensitive JavaScript or browser APIs on Scope. Exposing such objects on a Scope is never a good
// practice and therefore we are not even trying to protect against interaction with an object
// explicitly exposed in this way.
//
// In general, it is not possible to access a Window object from an angular expression unless a
// window or some DOM object that has a reference to window is published onto a Scope.
// Similarly we prevent invocations of function known to be dangerous, as well as assignments to
// native objects.
//
// See https://docs.angularjs.org/guide/security
function ensureSafeMemberName(name, fullExpression) {
if (name === "__defineGetter__" || name === "__defineSetter__"
|| name === "__lookupGetter__" || name === "__lookupSetter__"
|| name === "__proto__") {
throw $parseMinErr('isecfld',
'Attempting to access a disallowed field in Angular expressions! '
+ 'Expression: {0}', fullExpression);
}
return name;
}
function getStringValue(name) {
// Property names must be strings. This means that non-string objects cannot be used
// as keys in an object. Any non-string object, including a number, is typecasted
// into a string via the toString method.
// -- MDN, https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Property_accessors#Property_names
//
// So, to ensure that we are checking the same `name` that JavaScript would use, we cast it
// to a string. It's not always possible. If `name` is an object and its `toString` method is
// 'broken' (doesn't return a string, isn't a function, etc.), an error will be thrown:
//
// TypeError: Cannot convert object to primitive value
//
// For performance reasons, we don't catch this error here and allow it to propagate up the call
// stack. Note that you'll get the same error in JavaScript if you try to access a property using
// such a 'broken' object as a key.
return name + '';
}
function ensureSafeObject(obj, fullExpression) {
// nifty check if obj is Function that is fast and works across iframes and other contexts
if (obj) {
if (obj.constructor === obj) {
throw $parseMinErr('isecfn',
'Referencing Function in Angular expressions is disallowed! Expression: {0}',
fullExpression);
} else if (// isWindow(obj)
obj.window === obj) {
throw $parseMinErr('isecwindow',
'Referencing the Window in Angular expressions is disallowed! Expression: {0}',
fullExpression);
} else if (// isElement(obj)
obj.children && (obj.nodeName || (obj.prop && obj.attr && obj.find))) {
throw $parseMinErr('isecdom',
'Referencing DOM nodes in Angular expressions is disallowed! Expression: {0}',
fullExpression);
} else if (// block Object so that we can't get hold of dangerous Object.* methods
obj === Object) {
throw $parseMinErr('isecobj',
'Referencing Object in Angular expressions is disallowed! Expression: {0}',
fullExpression);
}
}
return obj;
}
var CALL = Function.prototype.call;
var APPLY = Function.prototype.apply;
var BIND = Function.prototype.bind;
function ensureSafeFunction(obj, fullExpression) {
if (obj) {
if (obj.constructor === obj) {
throw $parseMinErr('isecfn',
'Referencing Function in Angular expressions is disallowed! Expression: {0}',
fullExpression);
} else if (obj === CALL || obj === APPLY || obj === BIND) {
throw $parseMinErr('isecff',
'Referencing call, apply or bind in Angular expressions is disallowed! Expression: {0}',
fullExpression);
}
}
}
function ensureSafeAssignContext(obj, fullExpression) {
if (obj) {
if (obj === (0).constructor || obj === (false).constructor || obj === ''.constructor ||
obj === {}.constructor || obj === [].constructor || obj === Function.constructor) {
throw $parseMinErr('isecaf',
'Assigning to a constructor is disallowed! Expression: {0}', fullExpression);
}
}
}
var OPERATORS = createMap();
forEach('+ - * / % === !== == != < > <= >= && || ! = |'.split(' '), function(operator) { OPERATORS[operator] = true; });
var ESCAPE = {"n":"\n", "f":"\f", "r":"\r", "t":"\t", "v":"\v", "'":"'", '"':'"'};
/////////////////////////////////////////
/**
* @constructor
*/
var Lexer = function(options) {
this.options = options;
};
Lexer.prototype = {
constructor: Lexer,
lex: function(text) {
this.text = text;
this.index = 0;
this.tokens = [];
while (this.index < this.text.length) {
var ch = this.text.charAt(this.index);
if (ch === '"' || ch === "'") {
this.readString(ch);
} else if (this.isNumber(ch) || ch === '.' && this.isNumber(this.peek())) {
this.readNumber();
} else if (this.isIdent(ch)) {
this.readIdent();
} else if (this.is(ch, '(){}[].,;:?')) {
this.tokens.push({index: this.index, text: ch});
this.index++;
} else if (this.isWhitespace(ch)) {
this.index++;
} else {
var ch2 = ch + this.peek();
var ch3 = ch2 + this.peek(2);
var op1 = OPERATORS[ch];
var op2 = OPERATORS[ch2];
var op3 = OPERATORS[ch3];
if (op1 || op2 || op3) {
var token = op3 ? ch3 : (op2 ? ch2 : ch);
this.tokens.push({index: this.index, text: token, operator: true});
this.index += token.length;
} else {
this.throwError('Unexpected next character ', this.index, this.index + 1);
}
}
}
return this.tokens;
},
is: function(ch, chars) {
return chars.indexOf(ch) !== -1;
},
peek: function(i) {
var num = i || 1;
return (this.index + num < this.text.length) ? this.text.charAt(this.index + num) : false;
},
isNumber: function(ch) {
return ('0' <= ch && ch <= '9') && typeof ch === "string";
},
isWhitespace: function(ch) {
// IE treats non-breaking space as \u00A0
return (ch === ' ' || ch === '\r' || ch === '\t' ||
ch === '\n' || ch === '\v' || ch === '\u00A0');
},
isIdent: function(ch) {
return ('a' <= ch && ch <= 'z' ||
'A' <= ch && ch <= 'Z' ||
'_' === ch || ch === '$');
},
isExpOperator: function(ch) {
return (ch === '-' || ch === '+' || this.isNumber(ch));
},
throwError: function(error, start, end) {
end = end || this.index;
var colStr = (isDefined(start)
? 's ' + start + '-' + this.index + ' [' + this.text.substring(start, end) + ']'
: ' ' + end);
throw $parseMinErr('lexerr', 'Lexer Error: {0} at column{1} in expression [{2}].',
error, colStr, this.text);
},
readNumber: function() {
var number = '';
var start = this.index;
while (this.index < this.text.length) {
var ch = lowercase(this.text.charAt(this.index));
if (ch == '.' || this.isNumber(ch)) {
number += ch;
} else {
var peekCh = this.peek();
if (ch == 'e' && this.isExpOperator(peekCh)) {
number += ch;
} else if (this.isExpOperator(ch) &&
peekCh && this.isNumber(peekCh) &&
number.charAt(number.length - 1) == 'e') {
number += ch;
} else if (this.isExpOperator(ch) &&
(!peekCh || !this.isNumber(peekCh)) &&
number.charAt(number.length - 1) == 'e') {
this.throwError('Invalid exponent');
} else {
break;
}
}
this.index++;
}
this.tokens.push({
index: start,
text: number,
constant: true,
value: Number(number)
});
},
readIdent: function() {
var start = this.index;
while (this.index < this.text.length) {
var ch = this.text.charAt(this.index);
if (!(this.isIdent(ch) || this.isNumber(ch))) {
break;
}
this.index++;
}
this.tokens.push({
index: start,
text: this.text.slice(start, this.index),
identifier: true
});
},
readString: function(quote) {
var start = this.index;
this.index++;
var string = '';
var rawString = quote;
var escape = false;
while (this.index < this.text.length) {
var ch = this.text.charAt(this.index);
rawString += ch;
if (escape) {
if (ch === 'u') {
var hex = this.text.substring(this.index + 1, this.index + 5);
if (!hex.match(/[\da-f]{4}/i)) {
this.throwError('Invalid unicode escape [\\u' + hex + ']');
}
this.index += 4;
string += String.fromCharCode(parseInt(hex, 16));
} else {
var rep = ESCAPE[ch];
string = string + (rep || ch);
}
escape = false;
} else if (ch === '\\') {
escape = true;
} else if (ch === quote) {
this.index++;
this.tokens.push({
index: start,
text: rawString,
constant: true,
value: string
});
return;
} else {
string += ch;
}
this.index++;
}
this.throwError('Unterminated quote', start);
}
};
var AST = function(lexer, options) {
this.lexer = lexer;
this.options = options;
};
AST.Program = 'Program';
AST.ExpressionStatement = 'ExpressionStatement';
AST.AssignmentExpression = 'AssignmentExpression';
AST.ConditionalExpression = 'ConditionalExpression';
AST.LogicalExpression = 'LogicalExpression';
AST.BinaryExpression = 'BinaryExpression';
AST.UnaryExpression = 'UnaryExpression';
AST.CallExpression = 'CallExpression';
AST.MemberExpression = 'MemberExpression';
AST.Identifier = 'Identifier';
AST.Literal = 'Literal';
AST.ArrayExpression = 'ArrayExpression';
AST.Property = 'Property';
AST.ObjectExpression = 'ObjectExpression';
AST.ThisExpression = 'ThisExpression';
AST.LocalsExpression = 'LocalsExpression';
// Internal use only
AST.NGValueParameter = 'NGValueParameter';
AST.prototype = {
ast: function(text) {
this.text = text;
this.tokens = this.lexer.lex(text);
var value = this.program();
if (this.tokens.length !== 0) {
this.throwError('is an unexpected token', this.tokens[0]);
}
return value;
},
program: function() {
var body = [];
while (true) {
if (this.tokens.length > 0 && !this.peek('}', ')', ';', ']'))
body.push(this.expressionStatement());
if (!this.expect(';')) {
return { type: AST.Program, body: body};
}
}
},
expressionStatement: function() {
return { type: AST.ExpressionStatement, expression: this.filterChain() };
},
filterChain: function() {
var left = this.expression();
var token;
while ((token = this.expect('|'))) {
left = this.filter(left);
}
return left;
},
expression: function() {
return this.assignment();
},
assignment: function() {
var result = this.ternary();
if (this.expect('=')) {
result = { type: AST.AssignmentExpression, left: result, right: this.assignment(), operator: '='};
}
return result;
},
ternary: function() {
var test = this.logicalOR();
var alternate;
var consequent;
if (this.expect('?')) {
alternate = this.expression();
if (this.consume(':')) {
consequent = this.expression();
return { type: AST.ConditionalExpression, test: test, alternate: alternate, consequent: consequent};
}
}
return test;
},
logicalOR: function() {
var left = this.logicalAND();
while (this.expect('||')) {
left = { type: AST.LogicalExpression, operator: '||', left: left, right: this.logicalAND() };
}
return left;
},
logicalAND: function() {
var left = this.equality();
while (this.expect('&&')) {
left = { type: AST.LogicalExpression, operator: '&&', left: left, right: this.equality()};
}
return left;
},
equality: function() {
var left = this.relational();
var token;
while ((token = this.expect('==','!=','===','!=='))) {
left = { type: AST.BinaryExpression, operator: token.text, left: left, right: this.relational() };
}
return left;
},
relational: function() {
var left = this.additive();
var token;
while ((token = this.expect('<', '>', '<=', '>='))) {
left = { type: AST.BinaryExpression, operator: token.text, left: left, right: this.additive() };
}
return left;
},
additive: function() {
var left = this.multiplicative();
var token;
while ((token = this.expect('+','-'))) {
left = { type: AST.BinaryExpression, operator: token.text, left: left, right: this.multiplicative() };
}
return left;
},
multiplicative: function() {
var left = this.unary();
var token;
while ((token = this.expect('*','/','%'))) {
left = { type: AST.BinaryExpression, operator: token.text, left: left, right: this.unary() };
}
return left;
},
unary: function() {
var token;
if ((token = this.expect('+', '-', '!'))) {
return { type: AST.UnaryExpression, operator: token.text, prefix: true, argument: this.unary() };
} else {
return this.primary();
}
},
primary: function() {
var primary;
if (this.expect('(')) {
primary = this.filterChain();
this.consume(')');
} else if (this.expect('[')) {
primary = this.arrayDeclaration();
} else if (this.expect('{')) {
primary = this.object();
} else if (this.selfReferential.hasOwnProperty(this.peek().text)) {
primary = copy(this.selfReferential[this.consume().text]);
} else if (this.options.literals.hasOwnProperty(this.peek().text)) {
primary = { type: AST.Literal, value: this.options.literals[this.consume().text]};
} else if (this.peek().identifier) {
primary = this.identifier();
} else if (this.peek().constant) {
primary = this.constant();
} else {
this.throwError('not a primary expression', this.peek());
}
var next;
while ((next = this.expect('(', '[', '.'))) {
if (next.text === '(') {
primary = {type: AST.CallExpression, callee: primary, arguments: this.parseArguments() };
this.consume(')');
} else if (next.text === '[') {
primary = { type: AST.MemberExpression, object: primary, property: this.expression(), computed: true };
this.consume(']');
} else if (next.text === '.') {
primary = { type: AST.MemberExpression, object: primary, property: this.identifier(), computed: false };
} else {
this.throwError('IMPOSSIBLE');
}
}
return primary;
},
filter: function(baseExpression) {
var args = [baseExpression];
var result = {type: AST.CallExpression, callee: this.identifier(), arguments: args, filter: true};
while (this.expect(':')) {
args.push(this.expression());
}
return result;
},
parseArguments: function() {
var args = [];
if (this.peekToken().text !== ')') {
do {
args.push(this.expression());
} while (this.expect(','));
}
return args;
},
identifier: function() {
var token = this.consume();
if (!token.identifier) {
this.throwError('is not a valid identifier', token);
}
return { type: AST.Identifier, name: token.text };
},
constant: function() {
// TODO check that it is a constant
return { type: AST.Literal, value: this.consume().value };
},
arrayDeclaration: function() {
var elements = [];
if (this.peekToken().text !== ']') {
do {
if (this.peek(']')) {
// Support trailing commas per ES5.1.
break;
}
elements.push(this.expression());
} while (this.expect(','));
}
this.consume(']');
return { type: AST.ArrayExpression, elements: elements };
},
object: function() {
var properties = [], property;
if (this.peekToken().text !== '}') {
do {
if (this.peek('}')) {
// Support trailing commas per ES5.1.
break;
}
property = {type: AST.Property, kind: 'init'};
if (this.peek().constant) {
property.key = this.constant();
} else if (this.peek().identifier) {
property.key = this.identifier();
} else {
this.throwError("invalid key", this.peek());
}
this.consume(':');
property.value = this.expression();
properties.push(property);
} while (this.expect(','));
}
this.consume('}');
return {type: AST.ObjectExpression, properties: properties };
},
throwError: function(msg, token) {
throw $parseMinErr('syntax',
'Syntax Error: Token \'{0}\' {1} at column {2} of the expression [{3}] starting at [{4}].',
token.text, msg, (token.index + 1), this.text, this.text.substring(token.index));
},
consume: function(e1) {
if (this.tokens.length === 0) {
throw $parseMinErr('ueoe', 'Unexpected end of expression: {0}', this.text);
}
var token = this.expect(e1);
if (!token) {
this.throwError('is unexpected, expecting [' + e1 + ']', this.peek());
}
return token;
},
peekToken: function() {
if (this.tokens.length === 0) {
throw $parseMinErr('ueoe', 'Unexpected end of expression: {0}', this.text);
}
return this.tokens[0];
},
peek: function(e1, e2, e3, e4) {
return this.peekAhead(0, e1, e2, e3, e4);
},
peekAhead: function(i, e1, e2, e3, e4) {
if (this.tokens.length > i) {
var token = this.tokens[i];
var t = token.text;
if (t === e1 || t === e2 || t === e3 || t === e4 ||
(!e1 && !e2 && !e3 && !e4)) {
return token;
}
}
return false;
},
expect: function(e1, e2, e3, e4) {
var token = this.peek(e1, e2, e3, e4);
if (token) {
this.tokens.shift();
return token;
}
return false;
},
selfReferential: {
'this': {type: AST.ThisExpression },
'$locals': {type: AST.LocalsExpression }
}
};
function ifDefined(v, d) {
return typeof v !== 'undefined' ? v : d;
}
function plusFn(l, r) {
if (typeof l === 'undefined') return r;
if (typeof r === 'undefined') return l;
return l + r;
}
function isStateless($filter, filterName) {
var fn = $filter(filterName);
return !fn.$stateful;
}
function findConstantAndWatchExpressions(ast, $filter) {
var allConstants;
var argsToWatch;
switch (ast.type) {
case AST.Program:
allConstants = true;
forEach(ast.body, function(expr) {
findConstantAndWatchExpressions(expr.expression, $filter);
allConstants = allConstants && expr.expression.constant;
});
ast.constant = allConstants;
break;
case AST.Literal:
ast.constant = true;
ast.toWatch = [];
break;
case AST.UnaryExpression:
findConstantAndWatchExpressions(ast.argument, $filter);
ast.constant = ast.argument.constant;
ast.toWatch = ast.argument.toWatch;
break;
case AST.BinaryExpression:
findConstantAndWatchExpressions(ast.left, $filter);
findConstantAndWatchExpressions(ast.right, $filter);
ast.constant = ast.left.constant && ast.right.constant;
ast.toWatch = ast.left.toWatch.concat(ast.right.toWatch);
break;
case AST.LogicalExpression:
findConstantAndWatchExpressions(ast.left, $filter);
findConstantAndWatchExpressions(ast.right, $filter);
ast.constant = ast.left.constant && ast.right.constant;
ast.toWatch = ast.constant ? [] : [ast];
break;
case AST.ConditionalExpression:
findConstantAndWatchExpressions(ast.test, $filter);
findConstantAndWatchExpressions(ast.alternate, $filter);
findConstantAndWatchExpressions(ast.consequent, $filter);
ast.constant = ast.test.constant && ast.alternate.constant && ast.consequent.constant;
ast.toWatch = ast.constant ? [] : [ast];
break;
case AST.Identifier:
ast.constant = false;
ast.toWatch = [ast];
break;
case AST.MemberExpression:
findConstantAndWatchExpressions(ast.object, $filter);
if (ast.computed) {
findConstantAndWatchExpressions(ast.property, $filter);
}
ast.constant = ast.object.constant && (!ast.computed || ast.property.constant);
ast.toWatch = [ast];
break;
case AST.CallExpression:
allConstants = ast.filter ? isStateless($filter, ast.callee.name) : false;
argsToWatch = [];
forEach(ast.arguments, function(expr) {
findConstantAndWatchExpressions(expr, $filter);
allConstants = allConstants && expr.constant;
if (!expr.constant) {
argsToWatch.push.apply(argsToWatch, expr.toWatch);
}
});
ast.constant = allConstants;
ast.toWatch = ast.filter && isStateless($filter, ast.callee.name) ? argsToWatch : [ast];
break;
case AST.AssignmentExpression:
findConstantAndWatchExpressions(ast.left, $filter);
findConstantAndWatchExpressions(ast.right, $filter);
ast.constant = ast.left.constant && ast.right.constant;
ast.toWatch = [ast];
break;
case AST.ArrayExpression:
allConstants = true;
argsToWatch = [];
forEach(ast.elements, function(expr) {
findConstantAndWatchExpressions(expr, $filter);
allConstants = allConstants && expr.constant;
if (!expr.constant) {
argsToWatch.push.apply(argsToWatch, expr.toWatch);
}
});
ast.constant = allConstants;
ast.toWatch = argsToWatch;
break;
case AST.ObjectExpression:
allConstants = true;
argsToWatch = [];
forEach(ast.properties, function(property) {
findConstantAndWatchExpressions(property.value, $filter);
allConstants = allConstants && property.value.constant;
if (!property.value.constant) {
argsToWatch.push.apply(argsToWatch, property.value.toWatch);
}
});
ast.constant = allConstants;
ast.toWatch = argsToWatch;
break;
case AST.ThisExpression:
ast.constant = false;
ast.toWatch = [];
break;
case AST.LocalsExpression:
ast.constant = false;
ast.toWatch = [];
break;
}
}
function getInputs(body) {
if (body.length != 1) return;
var lastExpression = body[0].expression;
var candidate = lastExpression.toWatch;
if (candidate.length !== 1) return candidate;
return candidate[0] !== lastExpression ? candidate : undefined;
}
function isAssignable(ast) {
return ast.type === AST.Identifier || ast.type === AST.MemberExpression;
}
function assignableAST(ast) {
if (ast.body.length === 1 && isAssignable(ast.body[0].expression)) {
return {type: AST.AssignmentExpression, left: ast.body[0].expression, right: {type: AST.NGValueParameter}, operator: '='};
}
}
function isLiteral(ast) {
return ast.body.length === 0 ||
ast.body.length === 1 && (
ast.body[0].expression.type === AST.Literal ||
ast.body[0].expression.type === AST.ArrayExpression ||
ast.body[0].expression.type === AST.ObjectExpression);
}
function isConstant(ast) {
return ast.constant;
}
function ASTCompiler(astBuilder, $filter) {
this.astBuilder = astBuilder;
this.$filter = $filter;
}
ASTCompiler.prototype = {
compile: function(expression, expensiveChecks) {
var self = this;
var ast = this.astBuilder.ast(expression);
this.state = {
nextId: 0,
filters: {},
expensiveChecks: expensiveChecks,
fn: {vars: [], body: [], own: {}},
assign: {vars: [], body: [], own: {}},
inputs: []
};
findConstantAndWatchExpressions(ast, self.$filter);
var extra = '';
var assignable;
this.stage = 'assign';
if ((assignable = assignableAST(ast))) {
this.state.computing = 'assign';
var result = this.nextId();
this.recurse(assignable, result);
this.return_(result);
extra = 'fn.assign=' + this.generateFunction('assign', 's,v,l');
}
var toWatch = getInputs(ast.body);
self.stage = 'inputs';
forEach(toWatch, function(watch, key) {
var fnKey = 'fn' + key;
self.state[fnKey] = {vars: [], body: [], own: {}};
self.state.computing = fnKey;
var intoId = self.nextId();
self.recurse(watch, intoId);
self.return_(intoId);
self.state.inputs.push(fnKey);
watch.watchId = key;
});
this.state.computing = 'fn';
this.stage = 'main';
this.recurse(ast);
var fnString =
// The build and minification steps remove the string "use strict" from the code, but this is done using a regex.
// This is a workaround for this until we do a better job at only removing the prefix only when we should.
'"' + this.USE + ' ' + this.STRICT + '";\n' +
this.filterPrefix() +
'var fn=' + this.generateFunction('fn', 's,l,a,i') +
extra +
this.watchFns() +
'return fn;';
/* jshint -W054 */
var fn = (new Function('$filter',
'ensureSafeMemberName',
'ensureSafeObject',
'ensureSafeFunction',
'getStringValue',
'ensureSafeAssignContext',
'ifDefined',
'plus',
'text',
fnString))(
this.$filter,
ensureSafeMemberName,
ensureSafeObject,
ensureSafeFunction,
getStringValue,
ensureSafeAssignContext,
ifDefined,
plusFn,
expression);
/* jshint +W054 */
this.state = this.stage = undefined;
fn.literal = isLiteral(ast);
fn.constant = isConstant(ast);
return fn;
},
USE: 'use',
STRICT: 'strict',
watchFns: function() {
var result = [];
var fns = this.state.inputs;
var self = this;
forEach(fns, function(name) {
result.push('var ' + name + '=' + self.generateFunction(name, 's'));
});
if (fns.length) {
result.push('fn.inputs=[' + fns.join(',') + '];');
}
return result.join('');
},
generateFunction: function(name, params) {
return 'function(' + params + '){' +
this.varsPrefix(name) +
this.body(name) +
'};';
},
filterPrefix: function() {
var parts = [];
var self = this;
forEach(this.state.filters, function(id, filter) {
parts.push(id + '=$filter(' + self.escape(filter) + ')');
});
if (parts.length) return 'var ' + parts.join(',') + ';';
return '';
},
varsPrefix: function(section) {
return this.state[section].vars.length ? 'var ' + this.state[section].vars.join(',') + ';' : '';
},
body: function(section) {
return this.state[section].body.join('');
},
recurse: function(ast, intoId, nameId, recursionFn, create, skipWatchIdCheck) {
var left, right, self = this, args, expression;
recursionFn = recursionFn || noop;
if (!skipWatchIdCheck && isDefined(ast.watchId)) {
intoId = intoId || this.nextId();
this.if_('i',
this.lazyAssign(intoId, this.computedMember('i', ast.watchId)),
this.lazyRecurse(ast, intoId, nameId, recursionFn, create, true)
);
return;
}
switch (ast.type) {
case AST.Program:
forEach(ast.body, function(expression, pos) {
self.recurse(expression.expression, undefined, undefined, function(expr) { right = expr; });
if (pos !== ast.body.length - 1) {
self.current().body.push(right, ';');
} else {
self.return_(right);
}
});
break;
case AST.Literal:
expression = this.escape(ast.value);
this.assign(intoId, expression);
recursionFn(expression);
break;
case AST.UnaryExpression:
this.recurse(ast.argument, undefined, undefined, function(expr) { right = expr; });
expression = ast.operator + '(' + this.ifDefined(right, 0) + ')';
this.assign(intoId, expression);
recursionFn(expression);
break;
case AST.BinaryExpression:
this.recurse(ast.left, undefined, undefined, function(expr) { left = expr; });
this.recurse(ast.right, undefined, undefined, function(expr) { right = expr; });
if (ast.operator === '+') {
expression = this.plus(left, right);
} else if (ast.operator === '-') {
expression = this.ifDefined(left, 0) + ast.operator + this.ifDefined(right, 0);
} else {
expression = '(' + left + ')' + ast.operator + '(' + right + ')';
}
this.assign(intoId, expression);
recursionFn(expression);
break;
case AST.LogicalExpression:
intoId = intoId || this.nextId();
self.recurse(ast.left, intoId);
self.if_(ast.operator === '&&' ? intoId : self.not(intoId), self.lazyRecurse(ast.right, intoId));
recursionFn(intoId);
break;
case AST.ConditionalExpression:
intoId = intoId || this.nextId();
self.recurse(ast.test, intoId);
self.if_(intoId, self.lazyRecurse(ast.alternate, intoId), self.lazyRecurse(ast.consequent, intoId));
recursionFn(intoId);
break;
case AST.Identifier:
intoId = intoId || this.nextId();
if (nameId) {
nameId.context = self.stage === 'inputs' ? 's' : this.assign(this.nextId(), this.getHasOwnProperty('l', ast.name) + '?l:s');
nameId.computed = false;
nameId.name = ast.name;
}
ensureSafeMemberName(ast.name);
self.if_(self.stage === 'inputs' || self.not(self.getHasOwnProperty('l', ast.name)),
function() {
self.if_(self.stage === 'inputs' || 's', function() {
if (create && create !== 1) {
self.if_(
self.not(self.nonComputedMember('s', ast.name)),
self.lazyAssign(self.nonComputedMember('s', ast.name), '{}'));
}
self.assign(intoId, self.nonComputedMember('s', ast.name));
});
}, intoId && self.lazyAssign(intoId, self.nonComputedMember('l', ast.name))
);
if (self.state.expensiveChecks || isPossiblyDangerousMemberName(ast.name)) {
self.addEnsureSafeObject(intoId);
}
recursionFn(intoId);
break;
case AST.MemberExpression:
left = nameId && (nameId.context = this.nextId()) || this.nextId();
intoId = intoId || this.nextId();
self.recurse(ast.object, left, undefined, function() {
self.if_(self.notNull(left), function() {
if (create && create !== 1) {
self.addEnsureSafeAssignContext(left);
}
if (ast.computed) {
right = self.nextId();
self.recurse(ast.property, right);
self.getStringValue(right);
self.addEnsureSafeMemberName(right);
if (create && create !== 1) {
self.if_(self.not(self.computedMember(left, right)), self.lazyAssign(self.computedMember(left, right), '{}'));
}