CODEWITHSUNDEEP
node.jsmongodbexpresspug
Max Sherbakov
Max Sherbakov

Reputation: 1955

how to passing few variables from mongodb query to jade tpl

//posts
var docs, cats;
var db = req.db;
var catcollection = db.get('catcollection');
var postcollection = db.get('postcollection');
 // find all post
     postcollection.find({},{},function(e,docs){
        console.log('posts ---> '+util.inspect(docs));
      }); // end find all post
    catcollection.find({},{},function(e,catss){
        cats=catss;
      console.log('cats --> '+util.inspect(cats)); //<<<---- write objects from mongo 

     }); // end find all cats for select

res.render('newpost', {
        posts : docs, cats:cats, title: 'Add New post'});

}); **//<<<---it  didn't passing the  cats:cats and post vars to jade **

jade template 

extends layout
  block content
   h1= title

   form#formAddPost(name="addpost",method="post",action="/addpost")

      input#inputPostTitle(type="text", placeholder="posttitle", name="posttitle")

         textarea#inputPostTitle(placeholder="postdesc", name="postdesc")

        textarea#inputPostTitle(placeholder="posttext", name="posttext")

       select#selectPostCats(placeholder="postdesc", name="posttext")
            each cat, i in cats
                     option(value="#{cat._id}") #{cat.titlecat}

         button#btnSubmit(type="submit") submit


  ul
     each post, i in posts
        li= i+" "
             a(href="/editpst/#{post._id}")=#{post.title}

I get this error message in jade tpl Cannot read property 'length' of undefined

but if I wrote 

   catcollection.find({},{},function(e,catss){
      cats=catss;
        console.log('cats --> '+util.inspect(cats));
    **res.render('newpost', {
          cats:cats, title: 'Add New post'});**

   }); // end find all cats for select

It passing category list to jade , but i can't pass post list to jade. How to passing few variables (posts and cats ) to jade tpl?

Upvotes: 2

Views: 165

Answers (1)

Explosion Pills
Explosion Pills

Reputation: 191809

Both of the .finds execute asynchronously so you don't know when (or if) either one will complete. That is to say you need to wait until both of the callbacks are called before you attempt to render the template.

The simplest way in your current implementation would be to nest everything:

postcollection.find({},{},function(e,docs){
  // handle errors
  catcollection.find({},{},function(e,cats){
    res.render('newpost', {
      posts : docs, cats:cats, title: 'Add New post'});
    });
  }); 
});

However you can do these queries simultaneously because they do not depend on each other. The best way to do that is to probably use promises.

Promise.all([postcollection.find(), catcollection.find()])
.then(function (docs, cats) {
    res.render('newpost', {
      posts : docs, cats:cats, title: 'Add New post'});
    });
});

This assumes that .find returns a promise. It should for the current Mongo driver.

Upvotes: 2

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