MVVM模式不但可用于Form表单,在复杂的管理页面中也能大显身手。例如,分页显示Blog的功能,我们先把后端代码写出来:
在apis.py中定义一个Page类用于存储分页信息:
class Page(object):
def __init__(self, item_count, page_index=1, page_size=10):
self.item_count = item_count
self.page_size = page_size
self.page_count = item_count // page_size + (1 if item_count % page_size > 0 else 0)
if (item_count == 0) or (page_index < 1) or (page_index > self.page_count):
self.offset = 0
self.limit = 0
self.page_index = 1
else:
self.page_index = page_index
self.offset = self.page_size * (page_index - 1)
self.limit = self.page_size
self.has_next = self.page_index < self.page_count
self.has_previous = self.page_index > 1
在urls.py中实现API:
def _get_blogs_by_page():
total = Blog.count_all()
page = Page(total, _get_page_index())
blogs = Blog.find_by('order by created_at desc limit ?,?', page.offset, page.limit)
return blogs, page
@api
@get('/api/blogs')
def api_get_blogs():
blogs, page = _get_blogs_by_page()
return dict(blogs=blogs, page=page)
返回模板页面:
@view('manage_blog_list.html')
@get('/manage/blogs')
def manage_blogs():
return dict(page_index=_get_page_index(), user=ctx.request.user)
模板页面首先通过API:GET /api/blogs?page=?拿到Model:
{
"page": {
"has_next": true,
"page_index": 1,
"page_count": 2,
"has_previous": false,
"item_count": 12
},
"blogs": [...]
}
然后,通过Vue初始化MVVM:
<script>
function initVM(data) {
$('#div-blogs').show();
var vm = new Vue({
el: '#div-blogs',
data: {
blogs: data.blogs,
page: data.page
},
methods: {
previous: function () {
gotoPage(this.page.page_index - 1);
},
next: function () {
gotoPage(this.page.page_index + 1);
},
edit_blog: function (blog) {
location.assign('/manage/blogs/edit/' + blog.id);
}
}
});
}
$(function() {
getApi('/api/blogs?page={{ page_index }}', function (err, results) {
if (err) {
return showError(err);
}
$('#div-loading').hide();
initVM(results);
});
});
</script>
View的容器是#div-blogs,包含一个table,我们用v-repeat可以把Model的数组blogs直接变成多行的<tr>:
<div id="div-blogs" class="uk-width-1-1" style="display:none">
<table class="uk-table uk-table-hover">
<thead>
<tr>
<th class="uk-width-5-10">标题 / 摘要</th>
<th class="uk-width-2-10">作者</th>
<th class="uk-width-2-10">创建时间</th>
<th class="uk-width-1-10">操作</th>
</tr>
</thead>
<tbody>
<tr v-repeat="blog: blogs" >
<td>
<a target="_blank" v-attr="href: '/blog/'+blog.id" v-text="blog.name"></a>
</td>
<td>
<a target="_blank" v-attr="href: '/user/'+blog.user_id" v-text="blog.user_name"></a>
</td>
<td>
<span v-text="blog.created_at.toDateTime()"></span>
</td>
<td>
<a href="#0" v-on="click: edit_blog(blog)"><i class="uk-icon-edit"></i>
</td>
</tr>
</tbody>
</table>
<div class="uk-width-1-1 uk-text-center">
<ul class="uk-pagination">
<li v-if="! page.has_previous" class="uk-disabled"><span><i class="uk-icon-angle-double-left"></i></span></li>
<li v-if="page.has_previous"><a v-on="click: previous()" href="#0"><i class="uk-icon-angle-double-left"></i></a></li>
<li class="uk-active"><span v-text="page.page_index"></span></li>
<li v-if="! page.has_next" class="uk-disabled"><span><i class="uk-icon-angle-double-right"></i></span></li>
<li v-if="page.has_next"><a v-on="click: next()" href="#0"><i class="uk-icon-angle-double-right"></i></a></li>
</ul>
</div>
</div>
往Model的blogs数组中增加一个Blog元素,table就神奇地增加了一行;把blogs数组的某个元素删除,table就神奇地减少了一行。所有复杂的Model-View的映射逻辑全部由MVVM框架完成,我们只需要在HTML中写上v-repeat指令,就什么都不用管了。
可以把v-repeat="blog: blogs"看成循环代码,所以,可以在一个<tr>内部引用循环变量blog。v-text和v-attr指令分别用于生成文本和DOM节点属性。
完整的Blog列表页如下: