AngularJS 分页
AngularJS paging
我用 spring mvc 进行了 AngularJS 分页,效果很好,但是应用程序从数据库中获取了大量数据,所以当我获取第一页时应用程序非常慢,因为它获取了所有内容记录,谁能帮我解决这个问题?我想根据 angularJS 分页
从数据库中获取数据子集
Spring mvc 控制器
@RequestMapping(value = "/rest/contacts",
method = RequestMethod.GET,
produces = MediaType.APPLICATION_JSON_VALUE)
@Timed
public List<Contact> getAll() {
return contactRepository.findAll();
}
AngularJS 服务
pagingpocApp.factory('Contact', function ($resource) {
return $resource('app/rest/contacts/:id', {}, {
'query': { method: 'GET', isArray: true},
'get': { method: 'GET'}
});
});
AngularJS 控制器
pagingpocApp.controller('ContactController', function ($scope, $filter,resolvedContact, Contact, resolvedRole) {
$scope.contacts = resolvedContact;
var sortingOrder = 'firstName';
$scope.sortingOrder = sortingOrder;
$scope.reverse = false;
$scope.filteredItems = [];
$scope.groupedItems = [];
$scope.itemsPerPage = 10;
$scope.pagedItems = [];
$scope.currentPage = 0;
var searchMatch = function (haystack, needle) {
if (!needle) {
return true;
}
return haystack.toLowerCase().indexOf(needle.toLowerCase()) !== -1;
};
// init the filtered items
$scope.search = function () {
$scope.filteredItems = $filter('filter')($scope.contacts, function (item) {
for(var attr in item) {
if (searchMatch(item[attr], $scope.query))
return true;
}
return false;
});
// take care of the sorting order
if ($scope.sortingOrder !== '') {
$scope.filteredItems = $filter('orderBy')($scope.filteredItems, $scope.sortingOrder, $scope.reverse);
}
$scope.currentPage = 0;
// now group by pages
$scope.groupToPages();
};
// calculate page in place
$scope.groupToPages = function () {
$scope.pagedItems = [];
for (var i = 0; i < $scope.filteredItems.length; i++) {
if (i % $scope.itemsPerPage === 0) {
$scope.pagedItems[Math.floor(i / $scope.itemsPerPage)] = [ $scope.filteredItems[i] ];
} else {
$scope.pagedItems[Math.floor(i / $scope.itemsPerPage)].push($scope.filteredItems[i]);
}
}
};
$scope.range = function (start, end) {
var ret = [];
if (!end) {
end = start;
start = 0;
}
for (var i = start; i < end; i++) {
ret.push(i);
}
return ret;
};
$scope.prevPage = function () {
if ($scope.currentPage > 0) {
$scope.currentPage--;
}
};
$scope.nextPage = function () {
if ($scope.currentPage < $scope.pagedItems.length - 1) {
$scope.currentPage++;
}
};
$scope.setPage = function () {
$scope.currentPage = this.n;
};
// functions have been describe process the data for display
$scope.search();
// change sorting order
$scope.sort_by = function(newSortingOrder) {
if ($scope.sortingOrder == newSortingOrder)
$scope.reverse = !$scope.reverse;
$scope.sortingOrder = newSortingOrder;
// icon setup
$('th i').each(function(){
// icon reset
$(this).removeClass().addClass('icon-sort');
});
if ($scope.reverse)
$('th.'+new_sorting_order+' i').removeClass().addClass('icon-chevron-up');
else
$('th.'+new_sorting_order+' i').removeClass().addClass('icon-chevron-down');
};
});
一个快速的选择是在您的 API 上创建一个 get 方法,它只 returns 数据的一个子集,一次可能只有 25 个联系人,或者一两页数据。然后,您可以在 angular 中创建一项服务,每 3 秒左右进行一次 get 调用,以获取接下来的 25 个联系人。一种延迟加载技术。
Ben Nadel 出色地 in this article 概述了他的公司如何处理使用延迟加载技术加载到页面的大量图像。通读他的例子可以给你一个很好的起点。
编辑:我还建议您参考 this solution 以获得更接近您希望实现的目标的答案。他建议一旦找到数据就将其推送到您的控制器:
function MyCtrl($scope, $timeout, $q) {
var fetchOne = function() {
var deferred = $q.defer();
$timeout(function() {
deferred.resolve([random(), random() + 100, random() + 200]);
}, random() * 5000);
return deferred.promise;
};
$scope.scans = [];
for (var i = 0; i < 2; i++) {
fetchOne().then(function(items) {
angular.forEach(items, function(item) {
$scope.scans.push(item);
});
});
};
}
我用 spring mvc 进行了 AngularJS 分页,效果很好,但是应用程序从数据库中获取了大量数据,所以当我获取第一页时应用程序非常慢,因为它获取了所有内容记录,谁能帮我解决这个问题?我想根据 angularJS 分页
从数据库中获取数据子集Spring mvc 控制器
@RequestMapping(value = "/rest/contacts",
method = RequestMethod.GET,
produces = MediaType.APPLICATION_JSON_VALUE)
@Timed
public List<Contact> getAll() {
return contactRepository.findAll();
}
AngularJS 服务
pagingpocApp.factory('Contact', function ($resource) {
return $resource('app/rest/contacts/:id', {}, {
'query': { method: 'GET', isArray: true},
'get': { method: 'GET'}
});
});
AngularJS 控制器
pagingpocApp.controller('ContactController', function ($scope, $filter,resolvedContact, Contact, resolvedRole) {
$scope.contacts = resolvedContact;
var sortingOrder = 'firstName';
$scope.sortingOrder = sortingOrder;
$scope.reverse = false;
$scope.filteredItems = [];
$scope.groupedItems = [];
$scope.itemsPerPage = 10;
$scope.pagedItems = [];
$scope.currentPage = 0;
var searchMatch = function (haystack, needle) {
if (!needle) {
return true;
}
return haystack.toLowerCase().indexOf(needle.toLowerCase()) !== -1;
};
// init the filtered items
$scope.search = function () {
$scope.filteredItems = $filter('filter')($scope.contacts, function (item) {
for(var attr in item) {
if (searchMatch(item[attr], $scope.query))
return true;
}
return false;
});
// take care of the sorting order
if ($scope.sortingOrder !== '') {
$scope.filteredItems = $filter('orderBy')($scope.filteredItems, $scope.sortingOrder, $scope.reverse);
}
$scope.currentPage = 0;
// now group by pages
$scope.groupToPages();
};
// calculate page in place
$scope.groupToPages = function () {
$scope.pagedItems = [];
for (var i = 0; i < $scope.filteredItems.length; i++) {
if (i % $scope.itemsPerPage === 0) {
$scope.pagedItems[Math.floor(i / $scope.itemsPerPage)] = [ $scope.filteredItems[i] ];
} else {
$scope.pagedItems[Math.floor(i / $scope.itemsPerPage)].push($scope.filteredItems[i]);
}
}
};
$scope.range = function (start, end) {
var ret = [];
if (!end) {
end = start;
start = 0;
}
for (var i = start; i < end; i++) {
ret.push(i);
}
return ret;
};
$scope.prevPage = function () {
if ($scope.currentPage > 0) {
$scope.currentPage--;
}
};
$scope.nextPage = function () {
if ($scope.currentPage < $scope.pagedItems.length - 1) {
$scope.currentPage++;
}
};
$scope.setPage = function () {
$scope.currentPage = this.n;
};
// functions have been describe process the data for display
$scope.search();
// change sorting order
$scope.sort_by = function(newSortingOrder) {
if ($scope.sortingOrder == newSortingOrder)
$scope.reverse = !$scope.reverse;
$scope.sortingOrder = newSortingOrder;
// icon setup
$('th i').each(function(){
// icon reset
$(this).removeClass().addClass('icon-sort');
});
if ($scope.reverse)
$('th.'+new_sorting_order+' i').removeClass().addClass('icon-chevron-up');
else
$('th.'+new_sorting_order+' i').removeClass().addClass('icon-chevron-down');
};
});
一个快速的选择是在您的 API 上创建一个 get 方法,它只 returns 数据的一个子集,一次可能只有 25 个联系人,或者一两页数据。然后,您可以在 angular 中创建一项服务,每 3 秒左右进行一次 get 调用,以获取接下来的 25 个联系人。一种延迟加载技术。
Ben Nadel 出色地 in this article 概述了他的公司如何处理使用延迟加载技术加载到页面的大量图像。通读他的例子可以给你一个很好的起点。
编辑:我还建议您参考 this solution 以获得更接近您希望实现的目标的答案。他建议一旦找到数据就将其推送到您的控制器:
function MyCtrl($scope, $timeout, $q) {
var fetchOne = function() {
var deferred = $q.defer();
$timeout(function() {
deferred.resolve([random(), random() + 100, random() + 200]);
}, random() * 5000);
return deferred.promise;
};
$scope.scans = [];
for (var i = 0; i < 2; i++) {
fetchOne().then(function(items) {
angular.forEach(items, function(item) {
$scope.scans.push(item);
});
});
};
}