Setting dynamic scope variables in AngularJs - sco

2019-01-07 02:23发布

I have a string I have gotten from a routeParam or a directive attribute or whatever, and I want to create a variable on the scope based on this. So:

$scope.<the_string> = "something".

However, if the string contains one or more dots I want to split it and actually "drill down" into the scope. So 'foo.bar' should become $scope.foo.bar. This means that the simple version won't work!

// This will not work as assigning variables like this will not "drill down"
// It will assign to a variables named the exact string, dots and all.
var the_string = 'life.meaning';
$scope[the_string] = 42;
console.log($scope.life.meaning);  // <-- Nope! This is undefined.
console.log($scope['life.meaning']);  // <-- It is in here instead!

When reading a variable based on a string you can get this behavior by doing $scope.$eval(the_string), but how to do it when assigning a value?

8条回答
够拽才男人
2楼-- · 2019-01-07 03:08

If you are ok with using Lodash, you can do the thing you wanted in one line using _.set():

_.set(object, path, value) Sets the property value of path on object. If a portion of path does not exist it’s created.

https://lodash.com/docs#set

So your example would simply be: _.set($scope, the_string, something);

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贪生不怕死
3楼-- · 2019-01-07 03:10

If you were trying to do what I imagine you were trying to do, then you only have to treat scope like a regular JS object.

This is what I use for an API success response for JSON data array...

function(data){

    $scope.subjects = [];

    $.each(data, function(i,subject){
        //Store array of data types
        $scope.subjects.push(subject.name);

        //Split data in to arrays
        $scope[subject.name] = subject.data;
    });
}

Now {{subjects}} will return an array of data subject names, and in my example there would be a scope attribute for {{jobs}}, {{customers}}, {{staff}}, etc. from $scope.jobs, $scope.customers, $scope.staff

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