在Meteor应用中安排Mongo集合清理

Question

So I've created an app that basically allows my teammates to fill out and submit forms. In original testing, Meteor would randomly refresh the page (even though no dependent data sources had been updated), and they would lose the info already entered in the form. So I hacked together a two-way data binding solution by making the app generate a temporary document, in a separate Mongo collection, that would store the form data until the user completes and submits the form -- at which point, the app removes the temporary document. I also used iron router to dynamically generate a unique page using the new document's id.

My problem is that, if the user doesn't submit or cancel the form, the document doesn't get removed, and I'm left with a bunch of unnecessary data. I want to schedule a weekly clean up of that Meteor collection, but I have no idea how to do this. I'm not sure what code is relevant here, but I've included the event that creates and removes the temporary document:

Screens = new Meteor.Collection('screens') // where forms will ultimately be stored
Forms = new Meteor.Collection('forms') // form templates
NewScreen = new Meteor.Collection('newscreen') //used for temporary data storage

//event that generates temporary object when users start new form
'click [name=new-screen]': function(e, tmpl) {
      NewScreen.insert({
        first: '',
        role: this.position_name,
        answers: [],
        form_id: this._id,
        position_name: this.position_name,
        form_bundle: this.form_bundle,
        created_at: new Date
      });


//event that stores form data in the final collection, and removes the temporary storage document

'click [name=submit]': function(e, tmpl) {
      e.preventDefault();

      var newObj = {};
      var q_elements = $('.question-form li');
      var a_elements = $('textarea');
      var ca_elements = $('.correct-answer');
      var qa_bundle = []

      for(i=0; i<q_elements.length; i++){
        myObj={}
        myObj['question'] = q_elements[i].innerHTML;
        myObj['answer'] = a_elements[i+1].value;
        myObj['correct_answer'] = ca_elements[i].innerHTML.split('</b> ')[1];
        qa_bundle.push(myObj);
      }

      newObj['name'] = $('input')[0].value;
      newObj['prescreen_notes'] = $('#prescreen-notes')[0].value;
      newObj['role'] = this.position_name;
      newObj['qa_bundle'] = qa_bundle;
      newObj['created_at'] = new Date;


      Screens.insert(newObj);

      for(i=0;i<$('input').length; i++){
        $('input')[i].value = '';
      }

      for(i=0;i<$('textarea').length; i++){
        $('textarea')[i].value = '';
      }

      $('#new-id')[0].innerHTML = 'Link to candidate prescreen: <a href="/screens/' + Screens.find().fetch()[Screens.find().fetch().length-1]._id +'">' + Screens.find().fetch()[Screens.find().fetch().length-1]._id + '</a>';

      NewScreen.remove({_id: window.location.pathname.split('/')[window.location.pathname.split('/').length-1]})  
    },

If it helps, I've committed the version of the app that the "meteor build" command spits out to make it a node.js app, to a github repo here: https://github.com/gharezlak/prescreens

Answer 1

I think you can set a timeout event when user ask for the form. Event time can be hours or days based on you application logic.

When even is raised, you will check if form was submitted, and clean single document if needed.

Answer 2

Use the synced-cron package

SyncedCron.add({
  name: 'Cleanup NewScreen Colleciton',
  schedule: function(parser) {
    return parser.text('every weekend');
  },
  job: function() {
    var date = new Date();
    date.setDate(date.getDate() - 1);  // 1 day ago
    NewScreen.remove({createdAt: { $lt: date }})
  }
});

However, you may be better off storing these temporary values clientside in localstorage.