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Day 12 - 编写日志列表页

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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:

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 > 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__

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) {
    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,我们用v-repeat可以把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">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>
                    <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blogv-textv-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:

awesomepy-manage-blogs

参考源码

day-12



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