# Extending computed property of administration component

**URL:** <https://forum.shopware.com/t/extending-computed-property-of-administration-component/66821>\
**Category:** Programming (EN)\
**Created:** [8. Mai 2020 um 20:50 UTC](https://forum.shopware.com/t/extending-computed-property-of-administration-component/66821 "2020-05-08T20:50:09Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![JeroenBalk](https://avatars.discourse-cdn.com/v4/letter/j/7cd45c/32.png) [@JeroenBalk](https://forum.shopware.com/u/JeroenBalk)\
**Post date:** [8. Mai 2020 um 20:50 UTC](https://forum.shopware.com/t/extending-computed-property-of-administration-component/66821/1 "2020-05-08T20:50:09Z")

</div>

Hello,

I tried to extend a component in the administration, like explained on this page:&nbsp;[https://docs.shopware.com/en/shopware-platform-dev-en/developer-guide/administration/inheritance](https://docs.shopware.com/en/shopware-platform-dev-en/developer-guide/administration/inheritance)

I want to add an extra menu option in the sidebar list on the Content -\> Shopping Experiences page. So I created a plugin with the cli. In /src/Resources/app/administration/src/main I created the following code:

```
const { Component } = Shopware;

Component.extend('sw-cms-list', {
    computed: {
        sortPageTypes() {
            return [
                { value: '', name: this.$tc('sw-cms.sorting.labelSortByAllPages'), active: true },
                { value: 'page', name: this.$tc('sw-cms.sorting.labelSortByShopPages') },
                { value: 'landingpage', name: this.$tc('sw-cms.sorting.labelSortByLandingPages') },
                { value: 'product_list', name: this.$tc('sw-cms.sorting.labelSortByCategoryPages') },
                { value: 'custom_form', name: 'Custom form' }
            ];
        }
    }
});

```

My console shows an error:&nbsp;Uncaught TypeError: Cannot read property ‘template’ of undefined  
&nbsp; &nbsp; at Object.extend (commons.js?1588970146199238:1)  
&nbsp; &nbsp; at Object.0ZX1 (custom-forms.js?1588970147777:1)

So, what is exactly wrong with my extend? Why do I need to define a template since I only want to overwrite one function from computed?