jinja.js

/*!
 * Jinja Templating for JavaScript v0.1.8
 * https://github.com/sstur/jinja-js
 *
 * This is a slimmed-down Jinja2 implementation [http://jinja.pocoo.org/]
 *
 * In the interest of simplicity, it deviates from Jinja2 as follows:
 * - Line statements, cycle, super, macro tags and block nesting are not implemented
 * - auto escapes html by default (the filter is "html" not "e")
 * - Only "html" and "safe" filters are built in
 * - Filters are not valid in expressions; `foo|length > 1` is not valid
 * - Expression Tests (`if num is odd`) not implemented (`is` translates to `==` and `isnot` to `!=`)
 *
 * Notes:
 * - if property is not found, but method '_get' exists, it will be called with the property name (and cached)
 * - `{% for n in obj %}` iterates the object's keys; get the value with `{% for n in obj %}{{ obj[n] }}{% endfor %}`
 * - subscript notation `a[0]` takes literals or simple variables but not `a[item.key]`
 * - `.2` is not a valid number literal; use `0.2`
 *
 */
/*global require, exports, module, define */

(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
        typeof define === 'function' && define.amd ? define(['exports'], factory) :
            (global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.jinja = {}));
})(this, (function (jinja) {
    "use strict";
    var STRINGS = /'(\\.|[^'])*'|"(\\.|[^"'"])*"/g;
    var IDENTS_AND_NUMS = /([$_a-z][$\w]*)|([+-]?\d+(\.\d+)?)/g;
    var NUMBER = /^[+-]?\d+(\.\d+)?$/;
    //non-primitive literals (array and object literals)
    var NON_PRIMITIVES = /\[[@#~](,[@#~])*\]|\[\]|\{([@i]:[@#~])(,[@i]:[@#~])*\}|\{\}/g;
    //bare identifiers such as variables and in object literals: {foo: 'value'}
    var IDENTIFIERS = /[$_a-z][$\w]*/ig;
    var VARIABLES = /i(\.i|\[[@#i]\])*/g;
    var ACCESSOR = /(\.i|\[[@#i]\])/g;
    var OPERATORS = /(===?|!==?|>=?|<=?|&&|\|\||[+\-\*\/%])/g;
    //extended (english) operators
    var EOPS = /(^|[^$\w])(and|or|not|is|isnot)([^$\w]|$)/g;
    var LEADING_SPACE = /^\s+/;
    var TRAILING_SPACE = /\s+$/;

    var START_TOKEN = /\{\{\{|\{\{|\{%|\{#/;
    var TAGS = {
        '{{{': /^('(\\.|[^'])*'|"(\\.|[^"'"])*"|.)+?\}\}\}/,
        '{{': /^('(\\.|[^'])*'|"(\\.|[^"'"])*"|.)+?\}\}/,
        '{%': /^('(\\.|[^'])*'|"(\\.|[^"'"])*"|.)+?%\}/,
        '{#': /^('(\\.|[^'])*'|"(\\.|[^"'"])*"|.)+?#\}/
    };

    var delimeters = {
        '{%': 'directive',
        '{{': 'output',
        '{#': 'comment'
    };

    var operators = {
        and: '&&',
        or: '||',
        not: '!',
        is: '==',
        isnot: '!='
    };

    var constants = {
        'true': true,
        'false': false,
        'null': null
    };

    function Parser() {
        this.nest = [];
        this.compiled = [];
        this.childBlocks = 0;
        this.parentBlocks = 0;
        this.isSilent = false;
    }

    Parser.prototype.push = function (line) {
        if (!this.isSilent) {
            this.compiled.push(line);
        }
    };

    Parser.prototype.parse = function (src) {
        this.tokenize(src);
        return this.compiled;
    };

    Parser.prototype.tokenize = function (src) {
        var lastEnd = 0, parser = this, trimLeading = false;
        matchAll(src, START_TOKEN, function (open, index, src) {
            //here we match the rest of the src against a regex for this tag
            var match = src.slice(index + open.length).match(TAGS[open]);
            match = (match ? match[0] : '');
            //here we sub out strings so we don't get false matches
            var simplified = match.replace(STRINGS, '@');
            //if we don't have a close tag or there is a nested open tag
            if (!match || ~simplified.indexOf(open)) {
                return index + 1;
            }
            var inner = match.slice(0, 0 - open.length);
            //check for white-space collapse syntax
            if (inner.charAt(0) === '-') var wsCollapseLeft = true;
            if (inner.slice(-1) === '-') var wsCollapseRight = true;
            inner = inner.replace(/^-|-$/g, '').trim();
            //if we're in raw mode and we are not looking at an "endraw" tag, move along
            if (parser.rawMode && (open + inner) !== '{%endraw') {
                return index + 1;
            }
            var text = src.slice(lastEnd, index);
            lastEnd = index + open.length + match.length;
            if (trimLeading) text = trimLeft(text);
            if (wsCollapseLeft) text = trimRight(text);
            if (wsCollapseRight) trimLeading = true;
            if (open === '{{{') {
                //liquid-style: make {{{x}}} => {{x|safe}}
                open = '{{';
                inner += '|safe';
            }
            parser.textHandler(text);
            parser.tokenHandler(open, inner);
        });
        var text = src.slice(lastEnd);
        if (trimLeading) text = trimLeft(text);
        this.textHandler(text);
    };

    Parser.prototype.textHandler = function (text) {
        this.push('write(' + JSON.stringify(text) + ');');
    };

    Parser.prototype.tokenHandler = function (open, inner) {
        var type = delimeters[open];
        if (type === 'directive') {
            this.compileTag(inner);
        } else if (type === 'output') {
            var extracted = this.extractEnt(inner, STRINGS, '@');
            //replace || operators with ~
            extracted.src = extracted.src.replace(/\|\|/g, '~').split('|');
            //put back || operators
            extracted.src = extracted.src.map(function (part) {
                return part.split('~').join('||');
            });
            var parts = this.injectEnt(extracted, '@');
            if (parts.length > 1) {
                var filters = parts.slice(1).map(this.parseFilter.bind(this));
                this.push('filter(' + this.parseExpr(parts[0]) + ',' + filters.join(',') + ');');
            } else {
                this.push('filter(' + this.parseExpr(parts[0]) + ');');
            }
        }
    };

    Parser.prototype.compileTag = function (str) {
        var directive = str.split(' ')[0];
        var handler = tagHandlers[directive];
        if (!handler) {
            throw new Error('Invalid tag: ' + str);
        }
        handler.call(this, str.slice(directive.length).trim());
    };

    Parser.prototype.parseFilter = function (src) {
        src = src.trim();
        var match = src.match(/[:(]/);
        var i = match ? match.index : -1;
        if (i < 0) return JSON.stringify([src]);
        var name = src.slice(0, i);
        var args = src.charAt(i) === ':' ? src.slice(i + 1) : src.slice(i + 1, -1);
        args = this.parseExpr(args, {terms: true});
        return '[' + JSON.stringify(name) + ',' + args + ']';
    };

    Parser.prototype.extractEnt = function (src, regex, placeholder) {
        var subs = [], isFunc = typeof placeholder == 'function';
        src = src.replace(regex, function (str) {
            var replacement = isFunc ? placeholder(str) : placeholder;
            if (replacement) {
                subs.push(str);
                return replacement;
            }
            return str;
        });
        return {src: src, subs: subs};
    };

    Parser.prototype.injectEnt = function (extracted, placeholder) {
        var src = extracted.src, subs = extracted.subs, isArr = Array.isArray(src);
        var arr = (isArr) ? src : [src];
        var re = new RegExp('[' + placeholder + ']', 'g'), i = 0;
        arr.forEach(function (src, index) {
            arr[index] = src.replace(re, function () {
                return subs[i++];
            });
        });
        return isArr ? arr : arr[0];
    };

    //replace complex literals without mistaking subscript notation with array literals
    Parser.prototype.replaceComplex = function (s) {
        var parsed = this.extractEnt(s, /i(\.i|\[[@#i]\])+/g, 'v');
        parsed.src = parsed.src.replace(NON_PRIMITIVES, '~');
        return this.injectEnt(parsed, 'v');
    };

    //parse expression containing literals (including objects/arrays) and variables (including dot and subscript notation)
    //valid expressions: `a + 1 > b.c or c == null`, `a and b[1] != c`, `(a < b) or (c < d and e)`, 'a || [1]`
    Parser.prototype.parseExpr = function (src, opts) {
        opts = opts || {};
        //extract string literals -> @
        var parsed1 = this.extractEnt(src, STRINGS, '@');
        //note: this will catch {not: 1} and a.is; could we replace temporarily and then check adjacent chars?
        parsed1.src = parsed1.src.replace(EOPS, function (s, before, op, after) {
            return (op in operators) ? before + operators[op] + after : s;
        });
        //sub out non-string literals (numbers/true/false/null) -> #
        // the distinction is necessary because @ can be object identifiers, # cannot
        var parsed2 = this.extractEnt(parsed1.src, IDENTS_AND_NUMS, function (s) {
            return (s in constants || NUMBER.test(s)) ? '#' : null;
        });
        //sub out object/variable identifiers -> i
        var parsed3 = this.extractEnt(parsed2.src, IDENTIFIERS, 'i');
        //remove white-space
        parsed3.src = parsed3.src.replace(/\s+/g, '');

        //the rest of this is simply to boil the expression down and check validity
        var simplified = parsed3.src;
        //sub out complex literals (objects/arrays) -> ~
        // the distinction is necessary because @ and # can be subscripts but ~ cannot
        while (simplified !== (simplified = this.replaceComplex(simplified))) ;
        //now @ represents strings, # represents other primitives and ~ represents non-primitives
        //replace complex variables (those with dot/subscript accessors) -> v
        while (simplified !== (simplified = simplified.replace(/i(\.i|\[[@#i]\])+/, 'v'))) ;
        //empty subscript or complex variables in subscript, are not permitted
        simplified = simplified.replace(/[iv]\[v?\]/g, 'x');
        //sub in "i" for @ and # and ~ and v (now "i" represents all literals, variables and identifiers)
        simplified = simplified.replace(/[@#~v]/g, 'i');
        //sub out operators
        simplified = simplified.replace(OPERATORS, '%');
        //allow 'not' unary operator
        simplified = simplified.replace(/!+[i]/g, 'i');
        var terms = opts.terms ? simplified.split(',') : [simplified];
        terms.forEach(function (term) {
            //simplify logical grouping
            while (term !== (term = term.replace(/\(i(%i)*\)/g, 'i'))) ;
            if (!term.match(/^i(%i)*/)) {
              throw new Error('Invalid expression: ' + src + " " + term);
            }
        });
        parsed3.src = parsed3.src.replace(VARIABLES, this.parseVar.bind(this));
        parsed2.src = this.injectEnt(parsed3, 'i');
        parsed1.src = this.injectEnt(parsed2, '#');
        return this.injectEnt(parsed1, '@');
    };

    Parser.prototype.parseVar = function (src) {
        var args = Array.prototype.slice.call(arguments);
        var str = args.pop(), index = args.pop();
        //quote bare object identifiers (might be a reserved word like {while: 1})
        if (src === 'i' && str.charAt(index + 1) === ':') {
            return '"i"';
        }
        var parts = ['"i"'];
        src.replace(ACCESSOR, function (part) {
            if (part === '.i') {
                parts.push('"i"');
            } else if (part === '[i]') {
                parts.push('get("i")');
            } else {
                parts.push(part.slice(1, -1));
            }
        });
        return 'get(' + parts.join(',') + ')';
    };

    //escapes a name to be used as a javascript identifier
    Parser.prototype.escName = function (str) {
        return str.replace(/\W/g, function (s) {
            return '$' + s.charCodeAt(0).toString(16);
        });
    };

    Parser.prototype.parseQuoted = function (str) {
        if (str.charAt(0) === "'") {
            str = str.slice(1, -1).replace(/\\.|"/, function (s) {
                if (s === "\\'") return "'";
                return s.charAt(0) === '\\' ? s : ('\\' + s);
            });
            str = '"' + str + '"';
        }
        //todo: try/catch or deal with invalid characters (linebreaks, control characters)
        return JSON.parse(str);
    };


    //the context 'this' inside tagHandlers is the parser instance
    var tagHandlers = {
        'if': function (expr) {
            this.push('if (' + this.parseExpr(expr) + ') {');
            this.nest.unshift('if');
        },
        'else': function () {
            if (this.nest[0] === 'for') {
                this.push('}, function() {');
            } else {
                this.push('} else {');
            }
        },
        'elseif': function (expr) {
            this.push('} else if (' + this.parseExpr(expr) + ') {');
        },
        'endif': function () {
            this.nest.shift();
            this.push('}');
        },
        'for': function (str) {
            var i = str.indexOf(' in ');
            var name = str.slice(0, i).trim();
            var expr = str.slice(i + 4).trim();
            this.push('each(' + this.parseExpr(expr) + ',' + JSON.stringify(name) + ',function() {');
            this.nest.unshift('for');
        },
        'endfor': function () {
            this.nest.shift();
            this.push('});');
        },
        'raw': function () {
            this.rawMode = true;
        },
        'endraw': function () {
            this.rawMode = false;
        },
        'set': function (stmt) {
            var i = stmt.indexOf('=');
            var name = stmt.slice(0, i).trim();
            var expr = stmt.slice(i + 1).trim();
            this.push('set(' + JSON.stringify(name) + ',' + this.parseExpr(expr) + ');');
        },
        'block': function (name) {
            if (this.isParent) {
                ++this.parentBlocks;
                var blockName = 'block_' + (this.escName(name) || this.parentBlocks);
                this.push('block(typeof ' + blockName + ' == "function" ? ' + blockName + ' : function() {');
            } else if (this.hasParent) {
                this.isSilent = false;
                ++this.childBlocks;
                blockName = 'block_' + (this.escName(name) || this.childBlocks);
                this.push('function ' + blockName + '() {');
            }
            this.nest.unshift('block');
        },
        'endblock': function () {
            this.nest.shift();
            if (this.isParent) {
                this.push('});');
            } else if (this.hasParent) {
                this.push('}');
                this.isSilent = true;
            }
        },
        'extends': function (name) {
            name = this.parseQuoted(name);
            var parentSrc = this.readTemplateFile(name);
            this.isParent = true;
            this.tokenize(parentSrc);
            this.isParent = false;
            this.hasParent = true;
            //silence output until we enter a child block
            this.isSilent = true;
        },
        'include': function (name) {
            name = this.parseQuoted(name);
            var incSrc = this.readTemplateFile(name);
            this.isInclude = true;
            this.tokenize(incSrc);
            this.isInclude = false;
        }
    };

    //liquid style
    tagHandlers.assign = tagHandlers.set;
    //python/django style
    tagHandlers.elif = tagHandlers.elseif;

    var getRuntime = function runtime(data, opts) {
        var defaults = {autoEscape: 'toJson'};
        var _toString = Object.prototype.toString;
        var _hasOwnProperty = Object.prototype.hasOwnProperty;
        var getKeys = Object.keys || function (obj) {
            var keys = [];
            for (var n in obj) if (_hasOwnProperty.call(obj, n)) keys.push(n);
            return keys;
        };
        var isArray = Array.isArray || function (obj) {
            return _toString.call(obj) === '[object Array]';
        };
        var create = Object.create || function (obj) {
            function F() {
            }

            F.prototype = obj;
            return new F();
        };
        var toString = function (val) {
            if (val == null) return '';
            return (typeof val.toString == 'function') ? val.toString() : _toString.call(val);
        };
        var extend = function (dest, src) {
            var keys = getKeys(src);
            for (var i = 0, len = keys.length; i < len; i++) {
                var key = keys[i];
                dest[key] = src[key];
            }
            return dest;
        };
        //get a value, lexically, starting in current context; a.b -> get("a","b")
        var get = function () {
            var val, n = arguments[0], c = stack.length;
            while (c--) {
                val = stack[c][n];
                if (typeof val != 'undefined') break;
            }
            for (var i = 1, len = arguments.length; i < len; i++) {
                if (val == null) continue;
                n = arguments[i];
                val = (_hasOwnProperty.call(val, n)) ? val[n] : (typeof val._get == 'function' ? (val[n] = val._get(n)) : null);
            }
            return (val == null) ? '' : val;
        };
        var set = function (n, val) {
            stack[stack.length - 1][n] = val;
        };
        var push = function (ctx) {
            stack.push(ctx || {});
        };
        var pop = function () {
            stack.pop();
        };
        var write = function (str) {
            output.push(str);
        };
        var filter = function (val) {
            for (var i = 1, len = arguments.length; i < len; i++) {
                var arr = arguments[i], name = arr[0], filter = filters[name];
                if (filter) {
                    arr[0] = val;
                    //now arr looks like [val, arg1, arg2]
                    val = filter.apply(data, arr);
                } else {
                    throw new Error('Invalid filter: ' + name);
                }
            }
            if (opts.autoEscape && name !== opts.autoEscape && name !== 'safe') {
                //auto escape if not explicitly safe or already escaped
                val = filters[opts.autoEscape].call(data, val);
            }
            output.push(val);
        };
        var each = function (obj, loopvar, fn1, fn2) {
            if (obj == null) return;
            var arr = isArray(obj) ? obj : getKeys(obj), len = arr.length;
            var ctx = {loop: {length: len, first: arr[0], last: arr[len - 1]}};
            push(ctx);
            for (var i = 0; i < len; i++) {
                extend(ctx.loop, {index: i + 1, index0: i});
                fn1(ctx[loopvar] = arr[i]);
            }
            if (len === 0 && fn2) fn2();
            pop();
        };
        var block = function (fn) {
            push();
            fn();
            pop();
        };
        var render = function () {
            return output.join('');
        };
        data = data || {};
        opts = extend(defaults, opts || {});
        var filters = extend({
            html: function (val) {
                return toString(val)
                    .split('&').join('&amp;')
                    .split('<').join('&lt;')
                    .split('>').join('&gt;')
                    .split('"').join('&quot;');
            },
            safe: function (val) {
                return val;
            },
            toJson: function (val) {
                if (typeof val === 'object') {
                    return JSON.stringify(val);
                }
                return toString(val);
            }
        }, opts.filters || {});
        var stack = [create(data || {})], output = [];
        return {
            get: get,
            set: set,
            push: push,
            pop: pop,
            write: write,
            filter: filter,
            each: each,
            block: block,
            render: render
        };
    };

    var runtime;

    jinja.compile = function (markup, opts) {
        opts = opts || {};
        var parser = new Parser();
        parser.readTemplateFile = this.readTemplateFile;
        var code = [];
        code.push('function render($) {');
        code.push('var get = $.get, set = $.set, push = $.push, pop = $.pop, write = $.write, filter = $.filter, each = $.each, block = $.block;');
        code.push.apply(code, parser.parse(markup));
        code.push('return $.render();');
        code.push('}');
        code = code.join('\n');
        if (opts.runtime === false) {
            var fn = new Function('data', 'options', 'return (' + code + ')(runtime(data, options))');
        } else {
            runtime = runtime || (runtime = getRuntime.toString());
            fn = new Function('data', 'options', 'return (' + code + ')((' + runtime + ')(data, options))');
        }
        return {render: fn};
    };

    jinja.render = function (markup, data, opts) {
        var tmpl = jinja.compile(markup);
        return tmpl.render(data, opts);
    };

    jinja.templateFiles = [];

    jinja.readTemplateFile = function (name) {
        var templateFiles = this.templateFiles || [];
        var templateFile = templateFiles[name];
        if (templateFile == null) {
            throw new Error('Template file not found: ' + name);
        }
        return templateFile;
    };


    /*!
     * Helpers
     */

    function trimLeft(str) {
        return str.replace(LEADING_SPACE, '');
    }

    function trimRight(str) {
        return str.replace(TRAILING_SPACE, '');
    }

    function matchAll(str, reg, fn) {
        //copy as global
        reg = new RegExp(reg.source, 'g' + (reg.ignoreCase ? 'i' : '') + (reg.multiline ? 'm' : ''));
        var match;
        while ((match = reg.exec(str))) {
            var result = fn(match[0], match.index, str);
            if (typeof result == 'number') {
                reg.lastIndex = result;
            }
        }
    }
}));