我正在为 SilverStripe 网站上的页面构建一些分页,默认情况下首先显示所有文章,但用户可以通过从下拉控件中选择年份来选择要查看的文章。
这是文章的模板。现在我有代码在页面首次加载或重新加载时添加分页,并且所有文章都是从服务器获取的:
<select id="SelectNewsYear">
<option value="">Select a year</option>
<% loop $GroupedNewsByDate.GroupedBy(PublishYear) %>
<option value="$PublishYear">$PublishYear</option>
<% end_loop %>
<option value="all">Show all</option>
</select>
<br /><br />
<div class="RecentNews">
<% loop $PaginatedReleases %>
$ArticleDate.format("F j, Y"), <a href="$URLSegment">$H1</a><br />
<% end_loop %>
<% if $PaginatedReleases.MoreThanOnePage %>
<% if $PaginatedReleases.NotFirstPage %>
<a class="prev" href="$PaginatedReleases.PrevLink">Prev</a>
<% end_if %>
<% loop $PaginatedReleases.Pages %>
<% if $CurrentBool %>
$PageNum
<% else %>
<% if $Link %>
<a href="$Link">$PageNum</a>
<% else %>
...
<% end_if %>
<% end_if %>
<% end_loop %>
<% if $PaginatedReleases.NotLastPage %>
<a class="next" href="$PaginatedReleases.NextLink">Next</a>
<% end_if %>
<% end_if %>
</div>
Page.php中的PaginatedReleases函数:
//Returns a paginted list of news releases
public function PaginatedReleases(){
$newslist = NewsReleaseArticlePage::get()->sort('ArticleDate', "DESC");
return new PaginatedList($newslist, $this->getRequest());
}
现在的问题是如何在从下拉列表中选择年份时保持分页功能。最初,我并不关心分页,因为我更关心下拉列表的功能。这是我目前设置的 jQuery 和 AJAX 代码,它从下拉列表中获取年份值并将其传递给服务器以执行相应的函数:
(function($) {
$(document).ready(function() {
var SelectNewsYear = $('#SelectNewsYear');
var month = new Array();
month[0] = "January";
month[1] = "February";
month[2] = "March";
month[3] = "April";
month[4] = "May";
month[5] = "June";
month[6] = "July";
month[7] = "August";
month[8] = "September";
month[9] = "October";
month[10] = "November";
month[11] = "December";
SelectNewsYear.change(function() {
if (SelectNewsYear.val() != "" && SelectNewsYear.val() != null && SelectNewsYear.find('option:selected').attr('value') !="all") {
sendYear();
}
else{
showAll();
}
});
//get all articles by the year selected
function sendYear(){
var year = SelectNewsYear.find('option:selected').attr('value');
$.ajax({
type: "POST",
url: "/home/getNewsByYear/"+year,
dataType: "json"
}).done(function (response) {
var list = '';
var newsSection = $('.RecentNewsByYear');
for (var i=0;i<response.length;i++){
var newsDate = new Date(response[i].date);
var monthFullName = month[newsDate.getUTCMonth()];
list += monthFullName + " " + newsDate.getUTCDate() +", " +newsDate.getFullYear() + ', ' + '<a href="' + response[i].article + '"target="_blank">' + response[i].title +"</a> <br />";
}
newsSection.empty();
newsSection.append(list);
});
}
});
}(jQuery));
$ = jQuery.noConflict();
以及 Page.php 中的 getNewsByYear 函数:
//Get all recent news by year based on selected year from dropdown
public function getNewsByYear(){
//Get the year selected by the dropdown
$newsReleaseYear = $this->getRequest()->param('ID');
//Group together all news that are associated with that selected year
$newsReleases = NewsReleaseArticlePage::get();
$return = array();
//put the news releases into the array that match the selected year
foreach($newsReleases as $newsRelease){
$newsDate = date("Y", strtotime($newsRelease->ArticleDate));
if($newsDate == $newsReleaseYear){
$return[] = array(
'title' => $newsRelease->H1,
'date' => $newsRelease->ArticleDate,
'article' => $newsRelease->URLSegment
);
}
}
return json_encode($return);
}
getNewsByYear 函数按原样运行良好,但我不确定如何在此处合并 SilverStripe PaginationList 功能。我想知道是否有一种方法可以在不依赖 json 编码数据的情况下返回所选文章?
最佳答案
当您返回 JSON 以从 JSON 构建 HTML 标记时,肯定有改进的余地……
我还认为,以一种无需 JS 即可运行的方式编写您的应用程序逻辑,然后添加 JS 以逐步增强您的应用程序是一种很好的做法。这样您就不会将每个非 JS 设备/阅读器/用户拒之门外。
所以这就是我要做的(准备广泛的回答):
启用按年份过滤
首先,您希望能够按年份过滤您的记录。我认为您通过 URL 启用过滤的方法很好,所以这就是我们要做的:
1。获取分页列表,可选择按年份过滤
在您的 Controller 中,添加/修改以下方法:
public function PaginatedReleases($year = null)
{
$list = NewsReleaseArticlePage::get()->sort('ArticleDate', 'DESC');
if ($year) {
$list = $list->where(array('YEAR("ArticleDate") = ?' => $year));
}
return PaginatedList::create($list, $this->getRequest());
}
这将允许您通过传入 $year
获取所有条目,或仅获取特定年份的条目。参数。
2。将一年的 Action 添加到您的 Controller
public static $allowed_actions = array(
'year' => true
);
public function year()
{
$year = $this->request->param('ID');
$data = array(
'Year' => $year,
'PaginatedReleases' => $this->PaginatedReleases($year)
);
return $data;
}
运行后dev/build
,您应该已经能够通过更改 URL(例如 mypage/year/2016
或 mypage/year/2015
等)按年份过滤您的条目
使用带有下拉列表的表单进行过滤
将以下内容添加到您的 Controller 以创建一个表单来过滤您的条目:
public function YearFilterForm()
{
// get an array of all distinct years
$list = SQLSelect::create()
->addFrom('NewsReleaseArticlePage')
->selectField('YEAR("ArticleDate")', 'Year')
->setOrderBy('Year', 'DESC')
->addGroupBy('"Year"')->execute()->column('Year');
// create an associative array with years as keys & values
$values = array_combine($list, $list);
// our fields just contain the dropdown, which uses the year values
$fields = FieldList::create(array(
DropdownField::create(
'Year',
'Year',
$values,
$this->getRequest()->param('ID')
)->setHasEmptyDefault(true)->setEmptyString('(all)')
));
$actions = FieldList::create(array(
FormAction::create('doFilter', 'Submit')
));
return Form::create($this, 'YearFilterForm', $fields, $actions);
}
实现doFilter
功能。它只是重定向到正确的 URL,具体取决于选择的年份:
public function doFilter($data, $form)
{
if(empty($data['Year'])){
return $this->redirect($this->Link());
} else {
return $this->redirect($this->Link('year/' . $data['Year']));
}
}
不要忘记将表单名称添加到 allowed_actions
:
public static $allowed_actions = array(
'YearFilterForm' => true, // <- this should be added!
'year' => true
);
现在删除你的<select>
从您的模板输入字段并将其替换为:$YearFilterForm
.
运行后dev/build
,您应该有一个页面,其中包含允许按年份过滤的表单(具有工作分页)
启用 AJAX
使用 AJAX,我们希望能够只加载页面的更改部分。因此,首先要做的是:
1。为应该异步加载的内容创建一个单独的模板
创建模板 Includes/ArticleList.ss
<div id="ArticleList" class="RecentNews">
<% loop $PaginatedReleases %>
$ArticleDate.format("F j, Y"), <a href="$URLSegment">$H1</a><br />
<% end_loop %>
<% if $PaginatedReleases.MoreThanOnePage %>
<% if $PaginatedReleases.NotFirstPage %>
<a class="prev pagination" href="$PaginatedReleases.PrevLink">Prev</a>
<% end_if %>
<% loop $PaginatedReleases.Pages %>
<% if $CurrentBool %>
$PageNum
<% else %>
<% if $Link %>
<a href="$Link" class="pagination">$PageNum</a>
<% else %>
...
<% end_if %>
<% end_if %>
<% end_loop %>
<% if $PaginatedReleases.NotLastPage %>
<a class="next pagination" href="$PaginatedReleases.NextLink">Next</a>
<% end_if %>
<% end_if %>
</div>
然后您的页面模板可以精简为:
$YearFilterForm
<% include ArticleList %>
在 dev/build
之后,一切都应该像以前一样工作。
2。当通过 AJAX 请求页面时,提供部分内容
因为这会影响对 year
的调用和 index
(未过滤的条目),在您的 Controller 中创建一个辅助方法,如下所示:
protected function handleYearRequest(SS_HTTPRequest $request)
{
$year = $request->param('ID');
$data = array(
'Year' => $year,
'PaginatedReleases' => $this->PaginatedReleases($year)
);
if($request->isAjax()) {
// in case of an ajax request, render only the partial template
return $this->renderWith('ArticleList', $data);
} else {
// returning an array will cause the page to render normally
return $data;
}
}
然后您可以添加/修改 index
和 year
看起来相同的方法:
public function year()
{
return $this->handleYearRequest($this->request);
}
public function index()
{
return $this->handleYearRequest($this->request);
}
3。用一些 JavaScript 连接一切
(function($) {
$(function(){
// hide form actions, as we want to trigger form submittal
// automatically when dropdown changes
$("#Form_YearFilterForm .Actions").hide();
// bind a change event on the dropdown to automatically submit
$("#Form_YearFilterForm").on("change", "select", function (e) {
$("#Form_YearFilterForm").submit();
});
// handle form submit events
$("#Form_YearFilterForm").on("submit", function(e){
e.preventDefault();
var form = $(this);
$("#ArticleList").addClass("loading");
// submit form via ajax
$.post(
form.attr("action"),
form.serialize(),
function(data, status, xhr){
$("#ArticleList").replaceWith($(data));
}
);
return false;
});
// handle pagination clicks
$("body").on("click", "a.pagination", function (e) {
e.preventDefault();
$("#ArticleList").addClass("loading");
$.get(
$(this).attr("href"),
function(data, status, xhr){
$("#ArticleList").replaceWith($(data));
}
);
return false;
});
});
})(jQuery);
结论
您现在有了一个可以在非 JS 设备上正常降级的解决方案。通过下拉菜单和分页进行过滤是启用 AJAX 的。标记未在 JS 和模板中定义,它只是负责标记的 SilverStripe 模板。
剩下要做的就是在内容刷新时添加漂亮的加载动画 ;)
关于php - SilverStripe - 根据下拉选择创建分页,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37685842/