Python版——博客网站<五> 编写日志列表页

开源地址：https://github.com/leebingbin/Python3.WebAPP.Blog

 

    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，咱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):
    '''
    Page object for display pages.
    '''

    def __init__(self, item_count, page_index=1, page_size=10):
        '''
        Init Pagination by item_count, page_index and page_size.

        >>> p1 = Page(100, 1)
        >>> p1.page_count
        10
        >>> p1.offset
        0
        >>> p1.limit
        10
        >>> p2 = Page(90, 9, 10)
        >>> p2.page_count
        9
        >>> p2.offset
        80
        >>> p2.limit
        10
        >>> p3 = Page(91, 10, 10)
        >>> p3.page_count
        10
        >>> p3.offset
        90
        >>> p3.limit
        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 > 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

    def __str__(self):
        return 'item_count: %s, page_count: %s, page_index: %s, page_size: %s, offset: %s, limit: %s' % (
            self.item_count, self.page_count, self.page_index, self.page_size, self.offset, self.limit)

    __repr__ = __str__

    在handlers.py中实现API：

@get('/api/blogs')
def api_blogs(*, page='1'):
    page_index = get_page_index(page)
    num = yield from Blog.findNumber('count(id)')
    p = Page(num, page_index)
    if num == 0:
        return dict(page=p, blogs=())
    blogs = yield from Blog.findAll(orderBy='created_at desc', limit=(p.offset, p.limit))
    return dict(page=p, blogs=blogs)

    管理页面：

@get('/manage/blogs')
def manage_blogs(*, page='1'):
    return {
        '__template__': 'manage_blogs.html',
        'page_index': get_page_index(page)
    }

    模板页面首先经过API：GET /api/blogs?page=?拿到Model：

{
    "page": {
        "has_next": true,
        "page_index": 1,
        "page_count": 2,
        "has_previous": false,
        "item_count": 15
    },
    "blogs": [...]
}

    而后，经过Vue初始化MVVM：

<script>
function initVM(data) {
    var vm = new Vue({
        el: '#vm',
        data: {
            blogs: data.blogs,
            page: data.page
        },
        methods: {
            edit_blog: function (blog) {
                location.assign('/manage/blogs/edit?id=' + blog.id);
            },
            delete_blog: function (blog) {
                if (confirm('确认要删除“' + blog.name + '”？删除后不可恢复！')) {
                    postJSON('/api/blogs/' + blog.id + '/delete', function (err, r) {
                        if (err) {
                            return alert(err.message || err.error || err);
                        }
                        refresh();
                    });
                }
            }
        }
    });
    $('#vm').show();
}
$(function() {
    getJSON('/api/blogs', {
        page: {{ page_index }}
    }, function (err, results) {
        if (err) {
            return fatal(err);
        }
        $('#loading').hide();
        initVM(results);
    });
});
</script>

    View的容器是#vm，包含一个table，咱们用v-repeat能够把Model的数组blogs直接变成多行的<tr>：

<div id="vm" class="uk-width-1-1">
    <a href="/manage/blogs/create" class="uk-button uk-button-primary"><i class="uk-icon-plus"></i> 新日志</a>

    <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">做者</th>
                <th class="uk-width-2-10">建立时间</th>
                <th class="uk-width-1-10">操做</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>
                    <a href="#0" v-on="click: delete_blog(blog)"><i class="uk-icon-trash-o"></i>
                </td>
            </tr>
        </tbody>
    </table>

    <div v-component="pagination" v-with="page"></div>
</div>

    往Model的blogs数组中增长一个Blog元素，table就神奇地增长了一行；把blogs数组的某个元素删除，table就神奇地减小了一行。全部复杂的Model-View的映射逻辑所有由MVVM框架完成，咱们只须要在HTML中写上v-repeat指令，就什么都不用管了。

    能够把v-repeat="blog: blogs"当作循环代码，因此，能够在一个<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。

 

 

 

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