javascript - 如何从使用 jquery 添加的项目中删除属性

Question

我在我的 jsp 页面中使用以下 jquery 将自动完成选项添加到具有 id mytextfield 的文本字段。

jQuery(function(){
                            $("#mytextfield").autocomplete("popuppages/listall.jsp");
});

在同一个页面中，有些情况下我必须从这个文本字段中删除这个自动完成功能。 (也就是说，同一字段必须充当文本字段，而不会根据用户对先前字段和选项的输入自动完成)

有什么方法可以让我从 $("#mytextfield") 的特定项目中删除这个新添加的“自动完成”属性。

我其实想知道有没有删除添加属性的选项

万一有人想引用那个自动完成代码，我把它附在下面..

;(function($) {

$.fn.extend({
    autocomplete: function(urlOrData, options) {
        var isUrl = typeof urlOrData == "string";
        options = $.extend({}, $.Autocompleter.defaults, {
            url: isUrl ? urlOrData : null,
            data: isUrl ? null : urlOrData,
            delay: isUrl ? $.Autocompleter.defaults.delay : 10,
            max: options && !options.scroll ? 10 : 150
        }, options);

        // if highlight is set to false, replace it with a do-nothing function
        options.highlight = options.highlight || function(value) { return value; };

        // if the formatMatch option is not specified, then use formatItem for backwards compatibility
        options.formatMatch = options.formatMatch || options.formatItem;

        return this.each(function() {
            new $.Autocompleter(this, options);
        });
    },
    result: function(handler) {
        return this.bind("result", handler);
    },
    search: function(handler) {
        return this.trigger("search", [handler]);
    },
    flushCache: function() {
        return this.trigger("flushCache");
    },
    setOptions: function(options){
        return this.trigger("setOptions", [options]);
    },
    unautocomplete: function() {
        return this.trigger("unautocomplete");
    }
});

$.Autocompleter = function(input, options) {

    var KEY = {
        UP: 38,
        DOWN: 40,
        DEL: 46,
        TAB: 9,
        RETURN: 13,
        ESC: 27,
        COMMA: 188,
        PAGEUP: 33,
        PAGEDOWN: 34,
        BACKSPACE: 8
    };

    // Create $ object for input element
    var $input = $(input).attr("autocomplete", "off").addClass(options.inputClass);

    var timeout;
    var previousValue = "";
    var cache = $.Autocompleter.Cache(options);
    var hasFocus = 0;
    var lastKeyPressCode;
    var config = {
        mouseDownOnSelect: false
    };
    var select = $.Autocompleter.Select(options, input, selectCurrent, config);

    var blockSubmit;

    // prevent form submit in opera when selecting with return key
    $.browser.opera && $(input.form).bind("submit.autocomplete", function() {
        if (blockSubmit) {
            blockSubmit = false;
            return false;
        }
    });

    // only opera doesn't trigger keydown multiple times while pressed, others don't work with keypress at all
    $input.bind(($.browser.opera ? "keypress" : "keydown") + ".autocomplete", function(event) {
        // a keypress means the input has focus
        // avoids issue where input had focus before the autocomplete was applied
        hasFocus = 1;
        // track last key pressed
        lastKeyPressCode = event.keyCode;
        switch(event.keyCode) {

            case KEY.UP:
                event.preventDefault();
                if ( select.visible() ) {
                    select.prev();
                } else {
                    onChange(0, true);
                }
                break;

            case KEY.DOWN:
                event.preventDefault();
                if ( select.visible() ) {
                    select.next();
                } else {
                    onChange(0, true);
                }
                break;

            case KEY.PAGEUP:
                event.preventDefault();
                if ( select.visible() ) {
                    select.pageUp();
                } else {
                    onChange(0, true);
                }
                break;

            case KEY.PAGEDOWN:
                event.preventDefault();
                if ( select.visible() ) {
                    select.pageDown();
                } else {
                    onChange(0, true);
                }
                break;

            // matches also semicolon
            case options.multiple && $.trim(options.multipleSeparator) == "," && KEY.COMMA:
            case KEY.TAB:
            case KEY.RETURN:
                if( selectCurrent() ) {
                    // stop default to prevent a form submit, Opera needs special handling
                    event.preventDefault();
                    blockSubmit = true;
                    return false;
                }
                break;

            case KEY.ESC:
                select.hide();
                break;

            default:
                clearTimeout(timeout);
                timeout = setTimeout(onChange, options.delay);
                break;
        }
    }).focus(function(){
        // track whether the field has focus, we shouldn't process any
        // results if the field no longer has focus
        hasFocus++;
    }).blur(function() {
        hasFocus = 0;
        if (!config.mouseDownOnSelect) {
            hideResults();
        }
    }).click(function() {
        // show select when clicking in a focused field
        if ( hasFocus++ > 1 && !select.visible() ) {
            onChange(0, true);
        }
    }).bind("search", function() {
        // TODO why not just specifying both arguments?
        var fn = (arguments.length > 1) ? arguments[1] : null;
        function findValueCallback(q, data) {
            var result;
            if( data && data.length ) {
                for (var i=0; i < data.length; i++) {
                    if( data[i].result.toLowerCase() == q.toLowerCase() ) {
                        result = data[i];
                        break;
                    }
                }
            }
            if( typeof fn == "function" ) fn(result);
            else $input.trigger("result", result && [result.data, result.value]);
        }
        $.each(trimWords($input.val()), function(i, value) {
            request(value, findValueCallback, findValueCallback);
        });
    }).bind("flushCache", function() {
        cache.flush();
    }).bind("setOptions", function() {
        $.extend(options, arguments[1]);
        // if we've updated the data, repopulate
        if ( "data" in arguments[1] )
            cache.populate();
    }).bind("unautocomplete", function() {
        select.unbind();
        $input.unbind();
        $(input.form).unbind(".autocomplete");
    });


    function selectCurrent() {
        var selected = select.selected();
        if( !selected )
            return false;

        var v = selected.result;
        previousValue = v;

        if ( options.multiple ) {
            var words = trimWords($input.val());
            if ( words.length > 1 ) {
                var seperator = options.multipleSeparator.length;
                var cursorAt = $(input).selection().start;
                var wordAt, progress = 0;
                $.each(words, function(i, word) {
                    progress += word.length;
                    if (cursorAt <= progress) {
                        wordAt = i;
                        return false;
                    }
                    progress += seperator;
                });
                words[wordAt] = v;
                // TODO this should set the cursor to the right position, but it gets overriden somewhere
                //$.Autocompleter.Selection(input, progress + seperator, progress + seperator);
                v = words.join( options.multipleSeparator );
            }
            v += options.multipleSeparator;
        }

        $input.val(v);
        hideResultsNow();
        $input.trigger("result", [selected.data, selected.value]);
        return true;
    }

    function onChange(crap, skipPrevCheck) {
        if( lastKeyPressCode == KEY.DEL ) {
            select.hide();
            return;
        }

        var currentValue = $input.val();

        if ( !skipPrevCheck && currentValue == previousValue )
            return;

        previousValue = currentValue;

        currentValue = lastWord(currentValue);
        if ( currentValue.length >= options.minChars) {
            $input.addClass(options.loadingClass);
            if (!options.matchCase)
                currentValue = currentValue.toLowerCase();
            request(currentValue, receiveData, hideResultsNow);
        } else {
            stopLoading();
            select.hide();
        }
    };

    function trimWords(value) {
        if (!value)
            return [""];
        if (!options.multiple)
            return [$.trim(value)];
        return $.map(value.split(options.multipleSeparator), function(word) {
            return $.trim(value).length ? $.trim(word) : null;
        });
    }

    function lastWord(value) {
        if ( !options.multiple )
            return value;
        var words = trimWords(value);
        if (words.length == 1) 
            return words[0];
        var cursorAt = $(input).selection().start;
        if (cursorAt == value.length) {
            words = trimWords(value)
        } else {
            words = trimWords(value.replace(value.substring(cursorAt), ""));
        }
        return words[words.length - 1];
    }

    // fills in the input box w/the first match (assumed to be the best match)
    // q: the term entered
    // sValue: the first matching result
    function autoFill(q, sValue){
        // autofill in the complete box w/the first match as long as the user hasn't entered in more data
        // if the last user key pressed was backspace, don't autofill
        if( options.autoFill && (lastWord($input.val()).toLowerCase() == q.toLowerCase()) && lastKeyPressCode != KEY.BACKSPACE ) {
            // fill in the value (keep the case the user has typed)
            $input.val($input.val() + sValue.substring(lastWord(previousValue).length));
            // select the portion of the value not typed by the user (so the next character will erase)
            $(input).selection(previousValue.length, previousValue.length + sValue.length);
        }
    };

    function hideResults() {
        clearTimeout(timeout);
        timeout = setTimeout(hideResultsNow, 200);
    };

    function hideResultsNow() {
        var wasVisible = select.visible();
        select.hide();
        clearTimeout(timeout);
        stopLoading();
        if (options.mustMatch) {
            // call search and run callback
            $input.search(
                function (result){
                    // if no value found, clear the input box
                    if( !result ) {
                        if (options.multiple) {
                            var words = trimWords($input.val()).slice(0, -1);
                            $input.val( words.join(options.multipleSeparator) + (words.length ? options.multipleSeparator : "") );
                        }
                        else {
                            $input.val( "" );
                            $input.trigger("result", null);
                        }
                    }
                }
            );
        }
    };

    function receiveData(q, data) {
        if ( data && data.length && hasFocus ) {
            stopLoading();
            select.display(data, q);
            autoFill(q, data[0].value);
            select.show();
        } else {
            hideResultsNow();
        }
    };

    function request(term, success, failure) {
        if (!options.matchCase)
            term = term.toLowerCase();
        var data = cache.load(term);
        // recieve the cached data
        if (data && data.length) {
            success(term, data);
        // if an AJAX url has been supplied, try loading the data now
        } else if( (typeof options.url == "string") && (options.url.length > 0) ){

            var extraParams = {
                timestamp: +new Date()
            };
            $.each(options.extraParams, function(key, param) {
                extraParams[key] = typeof param == "function" ? param() : param;
            });

            $.ajax({
                // try to leverage ajaxQueue plugin to abort previous requests
                mode: "abort",
                // limit abortion to this input
                port: "autocomplete" + input.name,
                dataType: options.dataType,
                url: options.url,
                data: $.extend({
                    q: lastWord(term),
                    limit: options.max
                }, extraParams),
                success: function(data) {
                    var parsed = options.parse && options.parse(data) || parse(data);
                    cache.add(term, parsed);
                    success(term, parsed);
                }
            });
        } else {
            // if we have a failure, we need to empty the list -- this prevents the the [TAB] key from selecting the last successful match
            select.emptyList();
            failure(term);
        }
    };

    function parse(data) {
        var parsed = [];
        var rows = data.split("\n");
        for (var i=0; i < rows.length; i++) {
            var row = $.trim(rows[i]);
            if (row) {
                row = row.split("|");
                parsed[parsed.length] = {
                    data: row,
                    value: row[0],
                    result: options.formatResult && options.formatResult(row, row[0]) || row[0]
                };
            }
        }
        return parsed;
    };

    function stopLoading() {
        $input.removeClass(options.loadingClass);
    };

};

$.Autocompleter.defaults = {
    inputClass: "ac_input",
    resultsClass: "ac_results",
    loadingClass: "ac_loading",
    minChars: 1,
    delay: 400,
    matchCase: false,
    matchSubset: true,
    matchContains: false,
    cacheLength: 10,
    max: 100,
    mustMatch: false,
    extraParams: {},
    selectFirst: true,
    formatItem: function(row) { return row[0]; },
    formatMatch: null,
    autoFill: false,
    width: 0,
    multiple: false,
    multipleSeparator: ", ",
    highlight: function(value, term) {
        return value.replace(new RegExp("(?![^&;]+;)(?!<[^<>]*)(" + term.replace(/([\^\$\(\)\[\]\{\}\*\.\+\?\|\\])/gi, "\\$1") + ")(?![^<>]*>)(?![^&;]+;)", "gi"), "<strong>$1</strong>");
    },
    scroll: true,
    scrollHeight: 180
};

$.Autocompleter.Cache = function(options) {

    var data = {};
    var length = 0;

    function matchSubset(s, sub) {
        if (!options.matchCase) 
            s = s.toLowerCase();
        var i = s.indexOf(sub);
        if (options.matchContains == "word"){
            i = s.toLowerCase().search("\\b" + sub.toLowerCase());
        }
        if (i == -1) return false;
        return i == 0 || options.matchContains;
    };

    function add(q, value) {
        if (length > options.cacheLength){
            flush();
        }
        if (!data[q]){ 
            length++;
        }
        data[q] = value;
    }

    function populate(){
        if( !options.data ) return false;
        // track the matches
        var stMatchSets = {},
            nullData = 0;

        // no url was specified, we need to adjust the cache length to make sure it fits the local data store
        if( !options.url ) options.cacheLength = 1;

        // track all options for minChars = 0
        stMatchSets[""] = [];

        // loop through the array and create a lookup structure
        for ( var i = 0, ol = options.data.length; i < ol; i++ ) {
            var rawValue = options.data[i];
            // if rawValue is a string, make an array otherwise just reference the array
            rawValue = (typeof rawValue == "string") ? [rawValue] : rawValue;

            var value = options.formatMatch(rawValue, i+1, options.data.length);
            if ( value === false )
                continue;

            var firstChar = value.charAt(0).toLowerCase();
            // if no lookup array for this character exists, look it up now
            if( !stMatchSets[firstChar] ) 
                stMatchSets[firstChar] = [];

            // if the match is a string
            var row = {
                value: value,
                data: rawValue,
                result: options.formatResult && options.formatResult(rawValue) || value
            };

            // push the current match into the set list
            stMatchSets[firstChar].push(row);

            // keep track of minChars zero items
            if ( nullData++ < options.max ) {
                stMatchSets[""].push(row);
            }
        };

        // add the data items to the cache
        $.each(stMatchSets, function(i, value) {
            // increase the cache size
            options.cacheLength++;
            // add to the cache
            add(i, value);
        });
    }

    // populate any existing data
    setTimeout(populate, 25);

    function flush(){
        data = {};
        length = 0;
    }

    return {
        flush: flush,
        add: add,
        populate: populate,
        load: function(q) {
            if (!options.cacheLength || !length)
                return null;
            /* 
             * if dealing w/local data and matchContains than we must make sure
             * to loop through all the data collections looking for matches
             */
            if( !options.url && options.matchContains ){
                // track all matches
                var csub = [];
                // loop through all the data grids for matches
                for( var k in data ){
                    // don't search through the stMatchSets[""] (minChars: 0) cache
                    // this prevents duplicates
                    if( k.length > 0 ){
                        var c = data[k];
                        $.each(c, function(i, x) {
                            // if we've got a match, add it to the array
                            if (matchSubset(x.value, q)) {
                                csub.push(x);
                            }
                        });
                    }
                }               
                return csub;
            } else 
            // if the exact item exists, use it
            if (data[q]){
                return data[q];
            } else
            if (options.matchSubset) {
                for (var i = q.length - 1; i >= options.minChars; i--) {
                    var c = data[q.substr(0, i)];
                    if (c) {
                        var csub = [];
                        $.each(c, function(i, x) {
                            if (matchSubset(x.value, q)) {
                                csub[csub.length] = x;
                            }
                        });
                        return csub;
                    }
                }
            }
            return null;
        }
    };
};

$.Autocompleter.Select = function (options, input, select, config) {
    var CLASSES = {
        ACTIVE: "ac_over"
    };

    var listItems,
        active = -1,
        data,
        term = "",
        needsInit = true,
        element,
        list;

    // Create results
    function init() {
        if (!needsInit)
            return;
        element = $("<div/>")
        .hide()
        .addClass(options.resultsClass)
        .css("position", "absolute")
        .appendTo(document.body);

        list = $("<ul/>").appendTo(element).mouseover( function(event) {
            if(target(event).nodeName && target(event).nodeName.toUpperCase() == 'LI') {
                active = $("li", list).removeClass(CLASSES.ACTIVE).index(target(event));
                $(target(event)).addClass(CLASSES.ACTIVE);            
            }
        }).click(function(event) {
            $(target(event)).addClass(CLASSES.ACTIVE);
            select();
            // TODO provide option to avoid setting focus again after selection? useful for cleanup-on-focus
            input.focus();
            return false;
        }).mousedown(function() {
            config.mouseDownOnSelect = true;
        }).mouseup(function() {
            config.mouseDownOnSelect = false;
        });

        if( options.width > 0 )
            element.css("width", options.width);

        needsInit = false;
    } 

    function target(event) {
        var element = event.target;
        while(element && element.tagName != "LI")
            element = element.parentNode;
        // more fun with IE, sometimes event.target is empty, just ignore it then
        if(!element)
            return [];
        return element;
    }

    function moveSelect(step) {
        listItems.slice(active, active + 1).removeClass(CLASSES.ACTIVE);
        movePosition(step);
        var activeItem = listItems.slice(active, active + 1).addClass(CLASSES.ACTIVE);
        if(options.scroll) {
            var offset = 0;
            listItems.slice(0, active).each(function() {
                offset += this.offsetHeight;
            });
            if((offset + activeItem[0].offsetHeight - list.scrollTop()) > list[0].clientHeight) {
                list.scrollTop(offset + activeItem[0].offsetHeight - list.innerHeight());
            } else if(offset < list.scrollTop()) {
                list.scrollTop(offset);
            }
        }
    };

    function movePosition(step) {
        active += step;
        if (active < 0) {
            active = listItems.size() - 1;
        } else if (active >= listItems.size()) {
            active = 0;
        }
    }

    function limitNumberOfItems(available) {
        return options.max && options.max < available
            ? options.max
            : available;
    }

    function fillList() {
        list.empty();
        var max = limitNumberOfItems(data.length);
        for (var i=0; i < max; i++) {
            if (!data[i])
                continue;
            var formatted = options.formatItem(data[i].data, i+1, max, data[i].value, term);
            if ( formatted === false )
                continue;
            var li = $("<li/>").html( options.highlight(formatted, term) ).addClass(i%2 == 0 ? "ac_even" : "ac_odd").appendTo(list)[0];
            $.data(li, "ac_data", data[i]);
        }
        listItems = list.find("li");
        if ( options.selectFirst ) {
            listItems.slice(0, 1).addClass(CLASSES.ACTIVE);
            active = 0;
        }
        // apply bgiframe if available
        if ( $.fn.bgiframe )
            list.bgiframe();
    }

    return {
        display: function(d, q) {
            init();
            data = d;
            term = q;
            fillList();
        },
        next: function() {
            moveSelect(1);
        },
        prev: function() {
            moveSelect(-1);
        },
        pageUp: function() {
            if (active != 0 && active - 8 < 0) {
                moveSelect( -active );
            } else {
                moveSelect(-8);
            }
        },
        pageDown: function() {
            if (active != listItems.size() - 1 && active + 8 > listItems.size()) {
                moveSelect( listItems.size() - 1 - active );
            } else {
                moveSelect(8);
            }
        },
        hide: function() {
            element && element.hide();
            listItems && listItems.removeClass(CLASSES.ACTIVE);
            active = -1;
        },
        visible : function() {
            return element && element.is(":visible");
        },
        current: function() {
            return this.visible() && (listItems.filter("." + CLASSES.ACTIVE)[0] || options.selectFirst && listItems[0]);
        },
        show: function() {
            var offset = $(input).offset();
            element.css({
                width: typeof options.width == "string" || options.width > 0 ? options.width : $(input).width(),
                top: offset.top + input.offsetHeight,
                left: offset.left
            }).show();
            if(options.scroll) {
                list.scrollTop(0);
                list.css({
                    maxHeight: options.scrollHeight,
                    overflow: 'auto'
                });

                if($.browser.msie && typeof document.body.style.maxHeight === "undefined") {
                    var listHeight = 0;
                    listItems.each(function() {
                        listHeight += this.offsetHeight;
                    });
                    var scrollbarsVisible = listHeight > options.scrollHeight;
                    list.css('height', scrollbarsVisible ? options.scrollHeight : listHeight );
                    if (!scrollbarsVisible) {
                        // IE doesn't recalculate width when scrollbar disappears
                        listItems.width( list.width() - parseInt(listItems.css("padding-left")) - parseInt(listItems.css("padding-right")) );
                    }
                }

            }
        },
        selected: function() {
            var selected = listItems && listItems.filter("." + CLASSES.ACTIVE).removeClass(CLASSES.ACTIVE);
            return selected && selected.length && $.data(selected[0], "ac_data");
        },
        emptyList: function (){
            list && list.empty();
        },
        unbind: function() {
            element && element.remove();
        }
    };
};

$.fn.selection = function(start, end) {
    if (start !== undefined) {
        return this.each(function() {
            if( this.createTextRange ){
                var selRange = this.createTextRange();
                if (end === undefined || start == end) {
                    selRange.move("character", start);
                    selRange.select();
                } else {
                    selRange.collapse(true);
                    selRange.moveStart("character", start);
                    selRange.moveEnd("character", end);
                    selRange.select();
                }
            } else if( this.setSelectionRange ){
                this.setSelectionRange(start, end);
            } else if( this.selectionStart ){
                this.selectionStart = start;
                this.selectionEnd = end;
            }
        });
    }
    var field = this[0];
    if ( field.createTextRange ) {
        var range = document.selection.createRange(),
            orig = field.value,
            teststring = "<->",
            textLength = range.text.length;
        range.text = teststring;
        var caretAt = field.value.indexOf(teststring);
        field.value = orig;
        this.selection(caretAt, caretAt + textLength);
        return {
            start: caretAt,
            end: caretAt + textLength
        }
    } else if( field.selectionStart !== undefined ){
        return {
            start: field.selectionStart,
            end: field.selectionEnd
        }
    }
};

})(jQuery);

Answer 1

看起来您正在寻找自动完成的destroy 或disable 方法..

检查文档...

destroy

disable

$("#mytextfield").autocomplete( "destroy" )
$("#mytextfield").autocomplete( "disable" )

不同之处在于销毁后你无法重新启用它......但是在使用 enable 禁用后你可以重新启用它......