Add delay key stroke for filter

[longprao]

Added ability to add a delay for filter.

Test passed.

Usage:

$scope.tableParams = new ngTableParams({
    page: 1,            // show first page
    count: 10,          // count per page
    sorting: {
        _id: 'desc'     // initial sorting
    }
}, {
    total: 10,           // length of data
    filterDelay: 750,    // default value (milliseconds)
    getData: function($defer, params) {
        Transaction.get(params.url(), function(data) {
            params.total(data.total);
            $defer.resolve(data.data);
        });
    }
});

[longprao]

#137

#119

[coveralls]

Coverage remained the same when pulling 0242a33 on longprao:master into c83e219 on esvit:master.

[dylanlgs]

+1

Might also be nice to have a minimum number of characters for live filtering, or a incremental character filter. For instance, if filtering by a state (US states, or provinces in other countries) field, you may want to filter by 2 characters for postal abbreviations, but at least 4 characters for full state name, since the shortest one "Utah" has 4 chars.

[darioguarascio]

Definitely a must-have feauture. Thanks @longprao

[darioguarascio]

Did you think about custom filters ? I created a drop down one, and the delay affects that as well.
It would be great to have the delay being applied only to free input, not fixed ones like dropdowns, checkboxes, radio, etc.

[esvit]

thanks, I added your changes to master branch

[lijuenc]

Echoing what @disfasia said.

While having a filter delay on keystrokes is nice, the filterDelay setting currently applies to all filters on an ngTable. This means that whether or not the filter values come from a textbox (where a keystroke delay makes sense) or another source like the value of a drop-down select (where a keystroke delay does not make sense), there will always be a [###]ms delay.

If your tables use a combination of textbox and non-textbox sources for filters, the delay can get pretty jarring. My workaround right now is to just use a filterDelay of 0 across the board.

[qharlie]

Brilliant thanks @longprao