Question

假设我有一个能够找到集合中所有未结投注的函数：

app.get('/profile/bet-history', function(req, res, next){
        var user = req.user;
        if(user){
            Bet.find({$query : {"username" : user.username, "settled":false, "paired" : true}, $orderby : {_id : -1}})
                .then(function(doc){
                    res.render('profile/bet-history', {bets: doc, user: req.user}); 
            });
        }else{
            res.redirect('/login');
        }
    });

我有一个Handlebars模板，可以呈现上述bets和user数据：

<tbody>
    {{#if bets}}
        {{#each bets}}
            <tr>
                <td>{{date this.createdAt}}</td>
                <td>{{this.market}}({{this.bet}})</td>
                <td>{{this.stake}}</td>
                <td>{{this.odds}}</td>
                <td>{{render the potential returns here}}</td>
            </tr>
        {{/each}}
    {{else}}
        <tr>
            <td>
                <p>You have no matched bets. Please come back later.</p>
            </td>
        </tr>
    {{/if}}        
</tbody>

我想通过调用一些函数.find()对calcReturns()返回的每个单独结果执行快速“潜在回报”计算，该函数接收返回的投注并将投注乘以赔率然后再渲染函数的结果与.find()调用返回的数据一起，该调用在{{#each}}部分中呈现。一个关键要求是我想在外部.js文件中使用一个函数，我不想在Mongo数据库中使用另一个字段。

Answer 1

您可以在从数据库中检索到投注后在本地计算潜在回报。

app.get('/profile/bet-history', function(req, res, next){
        var user = req.user;
        if(user){
            Bet.find({$query : {"username" : user.username, "settled":false, "paired" : true}, $orderby : {_id : -1}})
                .then(function(doc){
                    // Add the potential_returns for our render object here
                    doc.forEach(function(x) {
                        // Calculate the potential returns
                        x.potential_returns = x.bet * x.odds
                    })
                    res.render('profile/bet-history', {bets: doc, user: req.user}); 
            });
        }else{
            res.redirect('/login');
        }
    });

potential_returns可以与<tr>

的其他属性相同的方式添加到doc

<tbody>
    {{#if bets}}
        {{#each bets}}
            <tr>
                <td>{{date this.createdAt}}</td>
                <td>{{this.market}}({{this.bet}})</td>
                <td>{{this.stake}}</td>
                <td>{{this.odds}}</td>
                <td>{{this.potential_returns}}</td>
            </tr>
        {{/each}}
    {{else}}
        <tr>
            <td>
                <p>You have no matched bets. Please come back later.</p>
            </td>
        </tr>
    {{/if}}        
</tbody>

Answer 2

扩展jervtub的答案，为了使用外部JS功能，这是最终的解决方案：

获取请求

var updates = require('./update.js');

app.get('/profile/bet-history', function(req, res, next){
        var user = req.user;
        if(user){
            Bet.find({$query : {"username" : user.username, "settled":false, "paired" : true}, $orderby : {_id : -1}})
                .then(function(doc){
                    // Add the potential_returns for our render object here
                    doc.forEach(function(x) {
                        updates.calcReturns(x);
                    })
                    res.render('profile/bet-history', {bets: doc, user: req.user}); 
            });
        }else{
            res.redirect('/login');
        }
});

Update.js文件

module.exports = {
    calcReturns : function(x){
        if(x.bet == "Back"){
            x.potential_returns = x.stake * x.odds + x.stake;
        }else{
            x.potential_returns = x.stake * 2;
        }
    }
};

把手模板

<tbody>
    {{#if bets}}
        {{#each bets}}
            <tr>
                <td>{{date this.createdAt}}</td>
                <td>{{this.market}}({{this.bet}})</td>
                <td>{{this.stake}}</td>
                <td>{{this.odds}}</td>
                <td>{{this.potential_returns}}</td>
            </tr>
        {{/each}}
    {{else}}
        <tr>
            <td>
                <p>You have no matched bets. Please come back later.</p>
            </td>
        </tr>
    {{/if}}        
</tbody>

使用Mongoose渲染额外数据会导致Handlebars

2 个答案: