Steps for ensuring the initial select option remains blank

Question

Steps for ensuring the initial select option remains blank

In my current project, I am utilizing AngularJS to implement ng-options for creating a <select> element.

Upon the initial page load with no option selected, the generated HTML appears as follows:

<select size="3" ng-model="item" ng-options="s.name for s in itemlist">
<option value="?" selected="selected"></option>
<option value="0">Item 1</option>
<option value="1">Item 2</option>
<option value="2">Item 3</option>
</select>

However, once an element is selected (e.g. Item 2), the blank first select disappears. This behavior occurs because the ng-model is set by the selected value. My intention is to always keep the first select option blank so that users can easily reset the filter.

javascript angularjs ng-options

Answer 1

Answer №1

Use this code snippet to accomplish the task:

<select size="3" model-bind="item" data-options="s.name for s in itemlist">
    <option value="">Choose an option</option>
</select>

Answer 2

Use this code snippet to accomplish the task:

<select size="3" model-bind="item" data-options="s.name for s in itemlist">
    <option value="">Choose an option</option>
</select>

Answer 3

Answer №2

For those who consider "null" to be a valid value for one of the options (imagine that "null" is a value of one of the items in typeOptions in the example below), I have discovered that the easiest way to ensure that an automatically added option is hidden is by using ng-if.

<select ng-options="option.value as option.name for option in typeOptions">
    <option value="" ng-if="false"></option>
</select>

Why use ng-if instead of ng-hide? Because you want CSS selectors targeting the first option inside the select element to only target the visible "real" options, not the hidden ones. This becomes particularly useful when utilizing Protractor for end-to-end testing and using by.css() to select select options for some reason.

Kevin - Gathered by Kevin

Answer 4

For those who consider "null" to be a valid value for one of the options (imagine that "null" is a value of one of the items in typeOptions in the example below), I have discovered that the easiest way to ensure that an automatically added option is hidden is by using ng-if.

<select ng-options="option.value as option.name for option in typeOptions">
    <option value="" ng-if="false"></option>
</select>

Why use ng-if instead of ng-hide? Because you want CSS selectors targeting the first option inside the select element to only target the visible "real" options, not the hidden ones. This becomes particularly useful when utilizing Protractor for end-to-end testing and using by.css() to select select options for some reason.

Kevin - Gathered by Kevin

Answer 5

Answer №3

If you want to skip using the ng-options and opt for using ng-repeat instead, you can do so by including a blank first option. Take a look at the example provided below.

<select size="3" ng-model="item">
    <option value="?" selected="selected"></option>
    <option ng-repeat="s in itemlist" value="{{s.value}}">{{s.name}}</option>
</select>

Answer 6

If you want to skip using the ng-options and opt for using ng-repeat instead, you can do so by including a blank first option. Take a look at the example provided below.

<select size="3" ng-model="item">
    <option value="?" selected="selected"></option>
    <option ng-repeat="s in itemlist" value="{{s.value}}">{{s.name}}</option>
</select>

Answer 7

Answer №4

Your optimal choice seems to be adding the empty item at the start of the itemlist.

Answer 8

Your optimal choice seems to be adding the empty item at the start of the itemlist.

Answer 9

Answer №5

The previous solution may introduce undesirable data into the model. To properly reset the model, please utilize the following directive: JS: Select Option

Directive"
 .directive('dropDown', function($filter) {
    return {

        require: 'ngModel',
        priority: 100,
        link: function(scope, element, attr, ngModel) {

            function parse(value) {

                if (value) {

                    if(value === "")
                    {
                        return "invalid"
                    }
                    else
                    {
                        return value;
                    }

                } else {
                    return;
                }
            }


            ngModel.$parsers.push(parse);

        }
    };
});

Answer 10

The previous solution may introduce undesirable data into the model. To properly reset the model, please utilize the following directive: JS: Select Option

Directive"
 .directive('dropDown', function($filter) {
    return {

        require: 'ngModel',
        priority: 100,
        link: function(scope, element, attr, ngModel) {

            function parse(value) {

                if (value) {

                    if(value === "")
                    {
                        return "invalid"
                    }
                    else
                    {
                        return value;
                    }

                } else {
                    return;
                }
            }


            ngModel.$parsers.push(parse);

        }
    };
});

Answer 11

Answer №6

After encountering a similar issue, I spent quite some time researching and eventually discovered that the root cause was related to the version of Angular I was using. If you are working with Angular 1.6.x, simply utilize the ng-value directive to resolve the issue.

Additionally, in my controller, I initialized a value like this:

$scope.item = 0;

Answer 12

After encountering a similar issue, I spent quite some time researching and eventually discovered that the root cause was related to the version of Angular I was using. If you are working with Angular 1.6.x, simply utilize the ng-value directive to resolve the issue.

Additionally, in my controller, I initialized a value like this:

$scope.item = 0;

Answer 13

Answer №7

        <select ng-model="userData.platform_id"
            ng-options="item.id as item.value for item in availablePlatformsList"
            ng-init="userData.platform_id=userData.platform_id||availablePlatformsList[0].id"></select>

Answer 14

        <select ng-model="userData.platform_id"
            ng-options="item.id as item.value for item in availablePlatformsList"
            ng-init="userData.platform_id=userData.platform_id||availablePlatformsList[0].id"></select>

Answer 15

Answer №8

Console

$scope.selection = '';

$scope.optionsList = {
   '' = '',
   'Option 0' = 1,
   'Option 1' = 2,
   'Option 2' = 3
};

Markup Language

<select data-ng-model="selection" data-ng-options="v as k for (k, v) in optionsList"></select>

Answer 16

Console

$scope.selection = '';

$scope.optionsList = {
   '' = '',
   'Option 0' = 1,
   'Option 1' = 2,
   'Option 2' = 3
};

Markup Language

<select data-ng-model="selection" data-ng-options="v as k for (k, v) in optionsList"></select>

Steps for ensuring the initial select option remains blank

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Answer №6

Answer №7

Answer №8

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