Feature/#343 performance of typeahead/select2 with thousands of users

[iCatCat]

1. Made perfomance tests for typeahead and select2 with 1000/5000/10000 and 50000 users. Typeahead works fast with large amounts of data. Select2 was already going slow with 5000 users.
   Adding new user to a DB was done with a following method:

'users.createUsers'(name, numberOfUsers) {
        console.log('-------------------------- METHOD: createUsers ');  
        for (let i = 1; i < numberOfUsers; i++) {  
            let newUser = name + i;  
            let newPassword = 'Password' +i;  
            let newEmail = 't@test' + newUser + '.de';  
            Accounts.createUser({username: newUser, password: newPassword, email: newEmail});              
            Meteor.users.update({'username': newUser}, {$set: {'emails.0.verified': true}});  
            console.log('Created user: ' + newUser + ' with password: ' + newPassword);  
    }  
}  

2. Performance of select2 was increased by searching data remote. Made tests with 5000 / 10000 and 15 000 users => works amazing

[migerh]

Looks good. Please check the code climate findings and fix them: https://codeclimate.com/github/4minitz/4minitz/pull/356

[migerh]

This function call is almost identical to the one in topicInfoItemEdit. The only difference appears to be a bool flag given to the responsiblesSearch meteor method (third parameter. It's true here and false in topicInfoItemEdit.js).

Can you please try to factor this out into a separate function and call that function from both locations?

[migerh]

This makes us open for a possible XSS attack, e.g. if the full name of a responsible user contains HTML/JavaScript. @felixble was already involved in safely handling raw html rendering, he may know more about how to mitigate this.

[felixble]

Yes, we had similar issues with our ConfirmationDialog which could be solved by using the blaze template engine.

Have a look at the function Blaze.renderWithData(templateOrView, data, parentNode, [nextNode], [parentView]).

I would suggest to prepare a simple array of responsibles containing the required data (responsibleId and fullname). Then you could provide a meteor template which consumes such an array and prints for each item an option-Element. Then you can use the function Blaze.renderWithData by passing the template, the data as well as the element selectResponsibles as parentNode. You can access the template with its name just like this: Template['template-name'].

The meteor docs says "If [the nextNode is] not provided, the template will be inserted as the last child of parentNode." (see Blaze.renderWithData So it should have the same effect as appending strings like you did before. Fortunately, the blaze engine takes care about sanitizing the raw html 👍