The QSelect component has two types of selection: single or multiple. This component opens up a menu for the selection list and action. A filter can also be used for longer lists.
In case you are looking for a dropdown “button” instead of “input” use Button Dropdown instead.
Design
Overview
WARNING
For your QSelect you can use only one of the main designs (filled, outlined, standout, borderless). You cannot use multiple as they are self-exclusive.
Decorators
Coloring
Clearable
As a helper, you can use clearable prop so user can reset model to null through an appended icon. The second QSelect in the example below is the equivalent of using clearable.
Disable and readonly
Slots with QBtn type “submit”
WARNING
When placing a QBtn with type “submit” in one of the “before”, “after”, “prepend”, or “append” slots of a QField, QInput or QSelect, you should also add a @click listener on the QBtn in question. This listener should call the method that submits your form. All “click” events in such slots are not propagated to their parent elements.
Menu transitions
WARNING
Please note that transitions do not work when using options-cover prop.
In the example below there’s a few transitions showcased. For a full list of transitions available, go to Transitions.
Options list display mode
By default QSelect shows the list of options as a menu on desktop and as a dialog on mobiles. You can force one behavior by using the behavior property.
WARNING
Please note that on iOS menu behavior might generate problems, especially when used in combination with use-input prop. You can use a conditional behavior prop like :behavior="$q.platform.is.ios === true ? 'dialog' : 'menu'" to use dialog mode only on iOS.
The model
WARNING
The model for single selection can be anything (String, Object, …) while the model for multiple selection must be an Array.
The model content can be influenced by emit-value prop as you’ll learn in “The options” section below.
The options
Options type
Affecting model
When emit-value is used, the model becomes the determined value from the specified selected option. Default is to emit the whole option. It makes sense to use it only when the options are of Object form.
When map-options is used, the model can contain only the value, and it will be mapped against the options to determine its label. There is a performance penalty involved, so use it only if absolutely necessary. It’s not needed, for example, if the model contains the whole Object (so contains the label prop).
Custom prop names
By default, QSelect looks at label, value, disable and sanitize props of each option from the options array Objects. But you can override those:
WARNING
If you use functions for custom props always check if the option is null. These functions are used both for options in the list and for the selected options.
Customizing menu options
WARNING
The list of options is rendered using virtual scroll, so if you render more than one element for an option you must set a q-virtual-scroll--with-prev class on all elements except the first one.
Here is another example where we add a QToggle to each option. The possibilities are endless.
By default, when there are no options, the menu won’t appear. But you can customize this scenario and specify what the menu should display.
Lazy loading
The following example shows a glimpse of how you can play with lazy loading the options. This means, along with many other things, that options prop is not required on first render.
You can dynamically load new options when scroll reaches the end:
Cover mode
Disable TAB selection
The display value
Filtering and autocomplete
Native attributes with “use-input”
All the attributes set on QSelect that are not in the list of props in the API will be passed to the native input field used (please check use-input prop description first to understand what it does) for filtering / autocomplete / adding new value. Some examples: autocomplete, placeholder.
More information: native input attributes.
Create new values
TIP
The following are just a few examples to get you started into making your own QSelect behavior. This is not exhaustive list of possibilities that QSelect offers.
It makes sense to use this feature along with use-input prop.
In order to enable the creation of new values, you need to either specify the new-value-mode prop and/or listen for @new-value event. If you use both, then the purpose of listening to @new-value would be only to override the new-value-mode in your custom scenarios.
The new-value-mode prop
The new-value-mode prop value specifies how the value should be added: add (adds a value, even if duplicate), add-unique (add only if NOT duplicate) or toggle (adds value if it’s not already in model, otherwise it removes it).
By using this prop you don’t need to also listen for @new-value event, unless you have some specific scenarios for which you want to override the behavior.
The @new-value event
The @new-value event is emitted with the value to be added and a done callback. The done callback has two optional parameters:
- the value to be added
- the behavior (same values of
new-value-modeprop, and when it is specified it overrides that prop – if it is used) – default behavior (if not usingnew-value-mode) is to add the value even if it would be a duplicate
Calling done() with no parameters simply empties the input box value, without tampering with the model in any way.
Using menu and filtering
Filtering and adding the new values to menu:
Filters new values (in the example below the value to be added requires at least 3 characters to pass), and does not add to menu:
Generating multiple values from input:
Sanitization
By default, all options (included selected ones) are sanitized. This means that displaying them in HTML format is disabled. However, if you require HTML on your options and you trust their content, then there are a few ways to do this.
You can force the HTML form of the menu options by:
- setting
htmlkey of the trusted option totrue(for specific trusted options) - or by setting
options-htmlprop of QSelect (for all options)
The displayed value of QSelect is displayed as HTML if:
- the
display-value-htmlprop of QSelect is set - or you are not using
display-valueand- the
options-htmlprop of QSelect is set - any selected option has
htmlkey set totrue
- the
WARNING
If you use selected or selected-item slots, then you are responsible for sanitization of the display value. The display-value-html prop will not apply.
Render performance
The render performance is NOT affected much by the number of options, unless map-options is used on a large set. Notice the infinite scroll in place which renders additional options as the user scrolls through the list.
TIP
- (Composition API) To get the best performance while using lots of options, do not wrap the array that you are passing in the
optionsprop with ref()/computed()/reactive()/etc. This allows Vue to skip making the list “responsive” to changes. - (Options API) To get the best performance while using lots of options, freeze the array that you are passing in the
optionsprop usingObject.freeze(items). This allows Vue to skip making the list “responsive” to changes.
Keyboard navigation
When QSelect is focused:
- pressing ENTER, ARROW DOWN (or SPACE if
use-inputis not set) will open the list of options - if
use-chipsis set:- pressing SHIFT + TAB will navigate backwards through the QChips (if a QChip is selected TAB will navigate forward through the QChips)
- pressing ENTER when a QChip is selected will remove that option from the selection
- pressing BACKSPACE will remove the last option from the selection (when
use-inputis set the input should be empty)
- pressing BACKSPACE when
clearableis set then:- it clears the model (with
nullvalue) for single selection - it removes the last added value for multiple selection
- it clears the model (with
- pressing TAB (or SHIFT + TAB if
use-chipsis not set or the first QChip is selected) will navigate to the next or previous focusable element on page - typing text (0 - 9 or A - Z) if
use-inputis not set will:- create a search buffer (will be reset when a new key is not typed for 1.5 seconds) that will be used to search in the options labels
- select the next option starting with that letter (after the current focused one) if the first key in buffer is typed multiple times
- select the next option (starting with the current focused one) that matches the typed text (the match is fuzzy - the option label should start with the first letter and contain all the letters)
When the list of options is opened:
- pressing ARROW UP or ARROW DOWN will navigate up or down in the list of options
- pressing PAGE UP or PAGE DOWN will navigate one page up or down in the list of options
- pressing HOME or END will navigate to the start or end of the list of options (only if you are not using
use-input, or the input is empty) - when navigating using arrow keys, navigation will wrap when reaching the start or end of the list
- pressing ENTER (or SPACE when
use-inputis not set, or TAB whenmultipleanddisable-tab-selectionare not set) when an option is selected in the list will:- select the option and close the list of options if
multipleanddisable-tab-selectionare not set - toggle the option if
multipleis set
- select the option and close the list of options if
Native form submit
When dealing with a native form which has an action and a method (eg. when using Quasar with ASP.NET controllers), you need to specify the name property on QSelect, otherwise formData will not contain it (if it should) - all value are converted to string (native behaviour, so do not use Object values):