Why do I have a JavaScript parser error with this

2019-08-28 04:17发布

问题:

I have a JavaScript parser plug-in in Visual Studios 2012 and it is throwing an error at line 30 of this code, which is the closing curly brace for the $.mask piece from Mr. Bush:

/*
    Masked Input plugin for jQuery
    Copyright (c) 2007-2013 Josh Bush (digitalbush.com)
    Licensed under the MIT license (http://digitalbush.com/projects/masked-input-plugin/#license)
    Version: 1.3.1
*/
 (function($) {
    function getPasteEvent() {
        var el = document.createElement('input'),
        name = 'onpaste';
        el.setAttribute(name, '');
        return (typeof el[name] === 'function') ? 'paste': 'input';
    }

    var pasteEventName = getPasteEvent() + ".mask",
    ua = navigator.userAgent,
    iPhone = /iphone/i.test(ua),
    android = /android/i.test(ua),
    caretTimeoutId;

    $.mask = {
        //Predefined character definitions
        definitions: {
            '9': "[0-9]",
            'a': "[A-Za-z]",
            '*': "[A-Za-z0-9]"
        },
        dataName: "rawMaskFn",
        placeholder: '_',
        };

    $.fn.extend({
        //Helper Function for Caret positioning
        caret: function(begin, end) {
            var range;

            if (this.length === 0 || this.is(":hidden")) {
                return;
            }

            if (typeof begin == 'number') {
                end = (typeof end === 'number') ? end: begin;
                return this.each(function() {
                    if (this.setSelectionRange) {
                        this.setSelectionRange(begin, end);
                    } else if (this.createTextRange) {
                        range = this.createTextRange();
                        range.collapse(true);
                        range.moveEnd('character', end);
                        range.moveStart('character', begin);
                        range.select();
                    }
                });
            } else {
                if (this[0].setSelectionRange) {
                    begin = this[0].selectionStart;
                    end = this[0].selectionEnd;
                } else if (document.selection && document.selection.createRange) {
                    range = document.selection.createRange();
                    begin = 0 - range.duplicate().moveStart('character', -100000);
                    end = begin + range.text.length;
                }
                return {
                    begin: begin,
                    end: end
                };
            }
        },
        unmask: function() {
            return this.trigger("unmask");
        },
        mask: function(mask, settings) {
            var input,
            defs,
            tests,
            partialPosition,
            firstNonMaskPos,
            len;

            if (!mask && this.length > 0) {
                input = $(this[0]);
                return input.data($.mask.dataName)();
            }
            settings = $.extend({
                placeholder: $.mask.placeholder,
                // Load default placeholder
                completed: null
            }, settings);

            defs = $.mask.definitions;
            tests = [];
            partialPosition = len = mask.length;
            firstNonMaskPos = null;

            $.each(mask.split(""), function(i, c) {
                if (c == '?') {
                    len--;
                    partialPosition = i;
                } else if (defs[c]) {
                    tests.push(new RegExp(defs[c]));
                    if (firstNonMaskPos === null) {
                        firstNonMaskPos = tests.length - 1;
                    }
                } else {
                    tests.push(null);
                }
            });

            return this.trigger("unmask").each(function() {
                var input = $(this),
                buffer = $.map(mask.split(""), function(c, i) {
                    if (c != '?') {
                        return defs[c] ? settings.placeholder: c;
                    }
                }),
                focusText = input.val();

                function seekNext(pos) {
                    while (++pos < len && !tests[pos]);
                    return pos;
                }

                function seekPrev(pos) {
                    while (--pos >= 0 && !tests[pos]);
                    return pos;
                }

                function shiftL(begin, end) {
                    var i,
                    j;

                    if (begin < 0) {
                        return;
                    }

                    for (i = begin, j = seekNext(end); i < len; i++) {
                        if (tests[i]) {
                            if (j < len && tests[i].test(buffer[j])) {
                                buffer[i] = buffer[j];
                                buffer[j] = settings.placeholder;
                            } else {
                                break;
                            }

                            j = seekNext(j);
                        }
                    }
                    writeBuffer();
                    input.caret(Math.max(firstNonMaskPos, begin));
                }

                function shiftR(pos) {
                    var i,
                    c,
                    j,
                    t;

                    for (i = pos, c = settings.placeholder; i < len; i++) {
                        if (tests[i]) {
                            j = seekNext(i);
                            t = buffer[i];
                            buffer[i] = c;
                            if (j < len && tests[j].test(t)) {
                                c = t;
                            } else {
                                break;
                            }
                        }
                    }
                }

                function keydownEvent(e) {
                    var k = e.which,
                    pos,
                    begin,
                    end;

                    //backspace, delete, and escape get special treatment
                    if (k === 8 || k === 46 || (iPhone && k === 127)) {
                        pos = input.caret();
                        begin = pos.begin;
                        end = pos.end;

                        if (end - begin === 0) {
                            begin = k !== 46 ? seekPrev(begin) : (end = seekNext(begin - 1));
                            end = k === 46 ? seekNext(end) : end;
                        }
                        clearBuffer(begin, end);
                        shiftL(begin, end - 1);

                        e.preventDefault();
                    } else if (k == 27) {
                        //escape
                        input.val(focusText);
                        input.caret(0, checkVal());
                        e.preventDefault();
                    }
                }

                function keypressEvent(e) {
                    var k = e.which,
                    pos = input.caret(),
                    p,
                    c,
                    next;

                    if (e.ctrlKey || e.altKey || e.metaKey || k < 32) {
                        //Ignore
                        return;
                    } else if (k) {
                        if (pos.end - pos.begin !== 0) {
                            clearBuffer(pos.begin, pos.end);
                            shiftL(pos.begin, pos.end - 1);
                        }

                        p = seekNext(pos.begin - 1);
                        if (p < len) {
                            c = String.fromCharCode(k);
                            if (tests[p].test(c)) {
                                shiftR(p);

                                buffer[p] = c;
                                writeBuffer();
                                next = seekNext(p);

                                if (android) {
                                    setTimeout($.proxy($.fn.caret, input, next), 0);
                                } else {
                                    input.caret(next);
                                }

                                if (settings.completed && next >= len) {
                                    settings.completed.call(input);
                                }
                            }
                        }
                        e.preventDefault();
                    }
                }

                function clearBuffer(start, end) {
                    var i;
                    for (i = start; i < end && i < len; i++) {
                        if (tests[i]) {
                            buffer[i] = settings.placeholder;
                        }
                    }
                }

                function writeBuffer() {
                    input.val(buffer.join(''));
                }

                function checkVal(allow) {
                    //try to place characters where they belong
                    var test = input.val(),
                    lastMatch = -1,
                    i,
                    c;

                    for (i = 0, pos = 0; i < len; i++) {
                        if (tests[i]) {
                            buffer[i] = settings.placeholder;
                            while (pos++<test.length) {
                                c = test.charAt(pos - 1);
                                if (tests[i].test(c)) {
                                    buffer[i] = c;
                                    lastMatch = i;
                                    break;
                                }
                            }
                            if (pos > test.length) {
                                break;
                            }
                        } else if (buffer[i] === test.charAt(pos) && i !== partialPosition) {
                            pos++;
                            lastMatch = i;
                        }
                    }
                    if (allow) {
                        writeBuffer();
                    } else if (lastMatch + 1 < partialPosition) {
                        input.val("");
                        clearBuffer(0, len);
                    } else {
                        writeBuffer();
                        input.val(input.val().substring(0, lastMatch + 1));
                    }
                    return (partialPosition ? i: firstNonMaskPos);
                }

                input.data($.mask.dataName, function() {
                    return $.map(buffer, function(c, i) {
                        return tests[i] && c != settings.placeholder ? c: null;
                    }).join('');
                });

                if (!input.attr("readonly"))
                    input.one("unmask", function() {
                    input.unbind(".mask").removeData($.mask.dataName);
                }).bind("focus.mask", function() {
                    clearTimeout(caretTimeoutId);
                    var pos,
                    moveCaret;

                    focusText = input.val();
                    pos = checkVal();

                    caretTimeoutId = setTimeout(function() {
                        writeBuffer();
                        if (pos == mask.length) {
                            input.caret(0, pos);
                        } else {
                            input.caret(pos);
                        }
                    }, 10);
                }).bind("blur.mask", function() {
                    checkVal();
                    if (input.val() != focusText)
                        input.change();
                }).bind("keydown.mask", keydownEvent).bind("keypress.mask", keypressEvent).bind(pasteEventName, function() {
                    setTimeout(function() {
                        var pos = checkVal(true);
                        input.caret(pos);
                        if (settings.completed && pos == input.val().length)
                            settings.completed.call(input);
                    }, 0);
                });
                checkVal();
                //Perform initial check for existing values
                });
        }
    });

})(jQuery);

I'm still pretty new to JS and jQuery, can anyone tell me why? I arrived here while investigating why the mask code was causing some errors in ie8.

Again, my parser doesn't like the closing curly of this block:

$.mask = {
    //Predefined character definitions
    definitions: {
        '9': "[0-9]",
        'a': "[A-Za-z]",
        '*': "[A-Za-z0-9]"
    },
    dataName: "rawMaskFn",
    placeholder: '_',
    };

Any help would be greatly appreciated!

回答1:

Maybe because of the additional comma after the placeholder: ... line?



回答2:

It looks like you've got an extra comma in there

$.mask = {
        //Predefined character definitions
        definitions: {
            '9': "[0-9]",
            'a': "[A-Za-z]",
            '*': "[A-Za-z0-9]"
        },
        dataName: "rawMaskFn",
        placeholder: '_'
        };


回答3:

    placeholder: '_',
};

There is a spare ,. It thinks that there should be one more member, but there isn't. Remove it and it will work.

    placeholder: '_'
};

The error comes from the line with }; because the error isn't the unneeded , but that the object ends before the last member.