Enables multisorting

[balping]

New property multiSort added. If it's false (default), everything works like before

However when it's set to true, you can sort data by several selected columns. The most recent selected column has the smallest precedence.

The generated request looks like this: ?sort=id|desc,name|asc,email|asc

Of course to get this working, you'll need a backend which is able to parse the above format.

Please note that this commit breaks backwards compatibility a bit. Now if you want to initialise the sort-order property, it should be done with an array like this. Just wrap your previous object in an array.

[{
    field: 'name',
    direction: 'asc'
}]

[ratiw]

@balping Nice! Just got a chance to look at your PR.

The breaking change is ok to me and it is necessary.

But I think it would be better if you could make the multisort to react to modifier key (like holding the ctrl or alt key while checking on the title to enable multisort) and clicking on the title without this modifier key will reset the sort to that column only. This could be achieve by passing $event as another argument to orderBy method like so,

    <th @click="orderBy(field, $event)"

and in the method declaration

    orderBy: function(field, event) {
        //...
        if (this.multisort && event.ctrlKey) {
            //...
        }
    }

What do you think? Would love to hear your opinion on this. :)

[balping]

@ratiw

Yes, I agree with you, it's probably more user friendly this way, so I added this functionality.

In addition I made another commit that marks fields with stronger precedence with darker color, like so: