I am trying to mimic the functionality of the right sidebar of this example for my Angular site.
I don't know what this is called, or even how to go about it on the front end or back end!
My assumption:
Create a form with values coming straight from the DB and only show the desired parameter (i.e. db.collection.find(query, {parameter: 1}) which will be called to update each time a user modifies the form. Additionally, the results would also be updated on selection (I have over 100MB of documents, returning ALL of them would be troublesome, how can I limit the number of documents returned to let's say 20 or 50 (user input?) and paginate it (1000 documents returned / 50 per page = 20 'pages')
Each input that is selected, a { 'field' : value } would be returned -- but I am not sure how to control an empty value (i.e. what if a user doesn't pick a fuel type or transmission range?)
How do I go about designing such a feature correctly?
1) In your query, use limit statement:
var options = { "limit": 20 }
collection.find({}, options).toArray(...);
2) you can validate user empty input (for eg. with express-validator):
req.checkBody('postparam', 'Invalid postparam').notEmpty()
req.getValidationResult().then(function(result) {
if (!result.isEmpty()) {
res.status(400).send('There have been validation errors: ' + util.inspect(result.array()));
return;
}
and based on result choose default value/pass error/render ask page for user