我遇到了这个问题,我不知道如何解决它。我在页面中使用了ui-select multiselect。首先,对获取数据的url进行http.get请求,然后填充ui-select选项。数据很大 - 数据长度为2100.此数据将显示为选项。 (数据在加载页面时在开头提取并存储在数组中)
但问题是每次我点击multiselect来选择一个选项时,填充列表需要4-5秒,页面变得很慢。我该怎么做才能减少这段时间?
选择数据存储在数组中,数据类型是字符串数组。
<ui-select multiple ng-model="selectedFields.name" style="width: 100%;">
<ui-select-match placeholder="Select fields...">{{$item}}</ui-select-match>
<ui-select-choices repeat="fields in availableFields | filter:$select.search">
{{fields}}
</ui-select-choices>
</ui-select>
在控制器中,
$scope.selectedFields = {};
$scope.selectedFields.name = [];
$scope.init = function() {
$http.get(url)
.success( function(response, status, headers, config) {
availableFields = response;
})
.error( function(err) {
});
};
$scope.init();
如果不是这样,是否还有其他选项/选择我可以使用哪些选项/选项不会延迟显示选择?
答案 0 :(得分:14)
这是ui-select中的已知问题。我尝试了以下方法,都工作
1)有一个解决方法 - 使用
| limitTo: 100
这会将选择显示限制为100,但可以选择所有选项。请查看this thread了解更多详情。
2)从某些时候开始,需要在选项中显示整个列表,1)不是一个可行的选择。我使用了不同的库 - selectize.js。这是页面中给出的plunker演示
答案 1 :(得分:6)
这是装饰uiSelectChoices
指令的完整解决方案。
用户滚动时会逐步填充项目。
还负责滚动搜索。
也适用于position={auto, up, down}
实施例
<ui-select-choices
position="up"
all-choices="ctrl.allTenThousandItems"
refresh-delay="0"
repeat="person in $select.pageOptions.people | propsFilter: {name: $select.search, age: $select.search} ">
<div ng-bind-html="person.name | highlight: $select.search"></div>
<small>
email: {{person.email}}
age: <span ng-bind-html="''+person.age | highlight: $select.search"></span>
</small>
</ui-select-choices>
指令
app.directive('uiSelectChoices', ['$timeout', '$parse', '$compile', '$document', '$filter', function($timeout, $parse, $compile, $document, $filter) {
return function(scope, elm, attr) {
var raw = elm[0];
var scrollCompleted = true;
if (!attr.allChoices) {
throw new Error('ief:ui-select: Attribute all-choices is required in ui-select-choices so that we can handle pagination.');
}
scope.pagingOptions = {
allOptions: scope.$eval(attr.allChoices)
};
attr.refresh = 'addMoreItems()';
var refreshCallBack = $parse(attr.refresh);
elm.bind('scroll', function(event) {
var remainingHeight = raw.offsetHeight - raw.scrollHeight;
var scrollTop = raw.scrollTop;
var percent = Math.abs((scrollTop / remainingHeight) * 100);
if (percent >= 80) {
if (scrollCompleted) {
scrollCompleted = false;
event.preventDefault();
event.stopPropagation();
var callback = function() {
scope.addingMore = true;
refreshCallBack(scope, {
$event: event
});
scrollCompleted = true;
};
$timeout(callback, 100);
}
}
});
var closeDestroyer = scope.$on('uis:close', function() {
var pagingOptions = scope.$select.pagingOptions || {};
pagingOptions.filteredItems = undefined;
pagingOptions.page = 0;
});
scope.addMoreItems = function(doneCalBack) {
console.log('new addMoreItems');
var $select = scope.$select;
var allItems = scope.pagingOptions.allOptions;
var moreItems = [];
var itemsThreshold = 100;
var search = $select.search;
var pagingOptions = $select.pagingOptions = $select.pagingOptions || {
page: 0,
pageSize: 20,
items: $select.items
};
if (pagingOptions.page === 0) {
pagingOptions.items.length = 0;
}
if (!pagingOptions.originalAllItems) {
pagingOptions.originalAllItems = scope.pagingOptions.allOptions;
}
console.log('search term=' + search);
console.log('prev search term=' + pagingOptions.prevSearch);
var searchDidNotChange = search && pagingOptions.prevSearch && search == pagingOptions.prevSearch;
console.log('isSearchChanged=' + searchDidNotChange);
if (pagingOptions.filteredItems && searchDidNotChange) {
allItems = pagingOptions.filteredItems;
}
pagingOptions.prevSearch = search;
if (search && search.length > 0 && pagingOptions.items.length < allItems.length && !searchDidNotChange) {
//search
if (!pagingOptions.filteredItems) {
//console.log('previous ' + pagingOptions.filteredItems);
}
pagingOptions.filteredItems = undefined;
moreItems = $filter('filter')(pagingOptions.originalAllItems, search);
//if filtered items are too many scrolling should occur for filtered items
if (moreItems.length > itemsThreshold) {
if (!pagingOptions.filteredItems) {
pagingOptions.page = 0;
pagingOptions.items.length = 0;
} else {
}
pagingOptions.page = 0;
pagingOptions.items.length = 0;
allItems = pagingOptions.filteredItems = moreItems;
} else {
allItems = moreItems;
pagingOptions.items.length = 0;
pagingOptions.filteredItems = undefined;
}
} else {
console.log('plain paging');
}
pagingOptions.page++;
if (pagingOptions.page * pagingOptions.pageSize < allItems.length) {
moreItems = allItems.slice(pagingOptions.items.length, pagingOptions.page * pagingOptions.pageSize);
}
for (var k = 0; k < moreItems.length; k++) {
pagingOptions.items.push(moreItems[k]);
}
scope.calculateDropdownPos();
scope.$broadcast('uis:refresh');
if (doneCalBack) doneCalBack();
};
scope.$on('$destroy', function() {
elm.off('scroll');
closeDestroyer();
});
};
}]);
答案 2 :(得分:4)
如上所述,ui-select存在相当多的性能问题,但是针对限制问题有一种解决方法。
如果您遵循akashrajkn的方法,那么您会注意到它实际上会删除重要的数据,因为它一次只会渲染100个。有一个修复已通过单元测试,它可以在这里的线程中找到:
https://github.com/angular-ui/ui-select/pull/716
基本上,如果您在本地存储javascript文件,则可以调整未分类的版本。您需要做的就是实现他在pull请求中所做的更改,它应该会有很大帮助。为了应用限制因素,请看下面的修改示例:
<ui-select multiple ng-model="selectedFields.name" limit = "10" style="width: 100%;">
<ui-select-match placeholder="Select fields...">{{$item}}</ui-select-match>
<ui-select-choices repeat="fields in availableFields | filter:$select.search | limitTo:$select.limit ">
{{fields}}
</ui-select-choices>
</ui-select>
以上内容将限制您在下拉列表中的数据,同时保持所需的一致性级别。
答案 3 :(得分:3)
因为我不能发表评论(没有足够的代表)我写这个作为答案,我很抱歉这个问题没有答案。
@bhantol我将以下代码行更改为您的解决方案,这对我来说非常适合我
for (var k = 0; k < moreItems.length; k++) {
pagingOptions.items.push(moreItems[k]);
}
for (var k = 0; k < moreItems.length; k++) {
if (pagingOptions.items.indexOf(moreItems[k]) == -1){
pagingOptions.items.push(moreItems[k]);
}
}
如果用户开始编写过滤器然后将其删除,这可以防止出现重复的项目。
另外我只是想通了如果列表小于20个项目它将无法工作所以我改变了:
if (pagingOptions.page * pagingOptions.pageSize < allItems.length) {
moreItems = allItems.slice(pagingOptions.items.length, pagingOptions.page * pagingOptions.pageSize);
}
到:
if (pagingOptions.page * pagingOptions.pageSize < allItems.length) {
moreItems = allItems.slice(pagingOptions.items.length, pagingOptions.page * pagingOptions.pageSize);
}
else{ moreItems = allItems;}
也许这会以某种方式帮助你,并且再次回答没有回答这个问题。