# Day 12 - 编写日志列表页 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`&lt;tr&gt;`： ``` <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`&lt;tr&gt;`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：