Tips for verifying query data in a Meteor helper and guiding to a 404 page

Question

Tips for verifying query data in a Meteor helper and guiding to a 404 page

Initially, I do not use Meteor by itself but Angular-Meteor. The underlying principles are still the same. My challenge involves validating a resource in a helper function to determine its validity and make decisions based on the outcome.

I assumed that the find and findOne collection functions worked synchronously on the client side, but it appears that either they are not or I am implementing them incorrectly.

This is the code snippet I have:

this.helpers({
      post() {
        let _post = Posts.findOne({
          _id: this.postId
        });

        if( typeof _post == 'undefined' )
          return this.$state.go('404');

        return _post;
      }
    });

The value of this.postId is obtained from the URL parameters. While navigating within the application, everything works as expected. However, when I refresh the page, even though this.postId is defined, Posts.find() returns undefined, resulting in a redirection to the 404 page.

How can I address this issue effectively?

javascript angularjs meteor angular-meteor meteor-collections

Answer 1

Answer №1

The issue occurs because the page is refreshed and the view is loaded before the data is transmitted to the client. To resolve this, ensure that the data is available before checking for its presence. Essentially, this entails confirming the readiness of your subscription by using the following code snippet as an example:

const subscription = Meteor.subscribe('data');

if (subscription.ready()) {
  const item = Items.findOne(/**/);

  if (typeof item === 'undefined') {
    console.log('item does not exist');
  }
}

Answer 2

The issue occurs because the page is refreshed and the view is loaded before the data is transmitted to the client. To resolve this, ensure that the data is available before checking for its presence. Essentially, this entails confirming the readiness of your subscription by using the following code snippet as an example:

const subscription = Meteor.subscribe('data');

if (subscription.ready()) {
  const item = Items.findOne(/**/);

  if (typeof item === 'undefined') {
    console.log('item does not exist');
  }
}

Answer 3

Answer №2

@Riley is absolutely correct regarding the timing of view rendering before data readiness.

An alternative approach is to utilize a reactive variable through this.observeReactively()

Here's how your helper would be structured:

this.helpers({
  article() {
    let _article = Articles.findOne({
      _id: this.observeReactively('articleId')
    });

    if( typeof _article == 'undefined' )
      return this.$state.go('404');

    return _article;
  }
});

The helper will initially run and yield no results (prior to data readiness), so your code must handle this scenario as standard practice (avoid using $state.go('404'))

Just ensure to initialize this.articleId in your constructor for proper functioning of observeReactively().

Answer 4

@Riley is absolutely correct regarding the timing of view rendering before data readiness.

An alternative approach is to utilize a reactive variable through this.observeReactively()

Here's how your helper would be structured:

this.helpers({
  article() {
    let _article = Articles.findOne({
      _id: this.observeReactively('articleId')
    });

    if( typeof _article == 'undefined' )
      return this.$state.go('404');

    return _article;
  }
});

The helper will initially run and yield no results (prior to data readiness), so your code must handle this scenario as standard practice (avoid using $state.go('404'))

Just ensure to initialize this.articleId in your constructor for proper functioning of observeReactively().

Tips for verifying query data in a Meteor helper and guiding to a 404 page

Answer №1

Answer №2

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