发布/订阅标准问题 [英] Pub/Sub Criteria Issue

问题描述

我正在尝试在客户端创建过滤机制.我只发布了未被删除的集合；{ 移除:false }.然后在客户端上，我有时想添加第二个条件 {tag: 'Sports'}.不幸的是，我的代码不起作用.我假设我的订阅参数会扩展发布的标准.也许我错了?

I'm trying to create a filtering mechanism on the client side. I've published only collections that have not been removed; { removed: false }. Then on the client I sometimes want to add a second criteria {tag: 'Sports'}. The code I have does not work, unfortunately. I assumed my arguments for the subscribe would extend the criteria of the publish. Maybe I am wrong?

服务器:

Meteor.publish('posts', function() {
    return Posts.find({ removed: false });
});

客户:

Meteor.subscribe('posts', { tag: 'Sports' })

推荐答案

第一个解决方案

服务器:

Meteor.publish('posts', function(query) {
    // if passed query is NULL, then query = {}
    query = query || {};
    // we need to be sure that always we filter by  {removed : false}
    query.removed = false;
    return Posts.find(query);
});

客户:

Meteor.subscribe('posts',{tag:'Sports'});

第二种解决方案

您的发布功能很好，您正在客户端进行第二次过滤.

Second solution

Your publish function is fine, second filtering you are doing on client side.

客户:

Meteor.subscribe('posts');

第二个条件可以在模板助手中使用:

The second criteria can be used inside Template helper:

Template.template_name.posts = function(){
   return Posts.find({tag:'Sports'});
}

你这样使用它:

<template name="posts">
 {{ posts }}
</template>

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