ngOptions: add tooltip to selection

问题

using the following json collection:

 $scope.searchscope = [

{ id: 0, name: "Base", description: "Search only the specified base object. The value is equal to 0." },
{ id: 1, name: "OneLevel", description: "Search the child objects of the base object, but not the base object itself.The value is equal to 1" },
{ id: 2, name: "Subtree", description: "Search the base object and all child objects. The value is equal to 2" }
];

and the following markup

 <select data-ng-model="mySelections[0].SearchFilterMembershipsScope" data-ng-options="i.id as i.name for i in searchscope" data-ng-required="true"></select>

I have successfully generated a select with the 3 options. What would be the best angular way to display a tooltip of the currently selected items "description"? Also would it be possible to do this whilst the user is navigating the dropdown, i.e. making a choice, verses actually had made the choice?

回答1:

You would need a map from id → description. One way to populate it would be:

$scope.idToDescription = null;

$scope.$watch("searchscope", function(newval) {
    if( newval != null ) {
        $scope.idToDescription = {};
        var i;
        for( i=0; i < newval.length; i++ ) {
            $scope.idToDescription[newval[i].id] = newval[i].description;
        }
    }
});

And in your template use it as:

<select ... 
    title="{{ idToDescription[mySelections[0].SearchFilterMembershipsScope] }}">

回答2:

If you are using Twitter Bootstrap, you might also consider looking at Tooltips in UI Bootstrap and if you want fancier select boxes consider using ui-select2 based on Select2.

来源：https://stackoverflow.com/questions/19679665/ngoptions-add-tooltip-to-selection