# Cannot link with custom widget

**URL:** https://discourse.paraview.org/t/cannot-link-with-custom-widget/14373
**Category:** Development
**Created:** [April 10, 2024, 9:26am UTC](https://discourse.paraview.org/t/cannot-link-with-custom-widget/14373 "2024-04-10T09:26:11Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![joint](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/j/dc4da7/32.png) [@joint](https://discourse.paraview.org/u/joint)
#### Post date: [April 10, 2024, 9:26am UTC](https://discourse.paraview.org/t/cannot-link-with-custom-widget/14373/1 "2024-04-10T09:26:11Z")

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Hello dear Paraview developers!

I have added my custom widget to Qt/ApplicationComponents

Then I tried to edit cmake in my plugin:

```auto
include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../../Qt/ApplicationComponents)
include_directories(${CMAKE_CURRENT_BINARY_DIR}/../../Qt/ApplicationComponents)

```

to use it in my plugin. However, I face linking issues

```auto
Severity	Code	Description	Project	File	Line	Suppression State	Details
Error	LNK2019	unresolved external symbol "protected: void __cdecl customWidget::process_clicked(void)" (?process_clicked@customWidget@@IEAAXXZ) referenced in function "private: void__cdecl pluginWidget::slotValueChanged(int)" (?slotValueChanged@pluginWidget2@@AEAAXH@Z)

```

I understand that the header is accessible, but the **definition cannot be found** , but I cant fix this, help me please

Best regards

---

<div class="post-metadata">

### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [April 17, 2024, 9:12am UTC](https://discourse.paraview.org/t/cannot-link-with-custom-widget/14373/2 "2024-04-17T09:12:28Z")

</div>

> my custom widget to Qt/ApplicationComponents

I’d suggest to not modify ParaView sources but indstead use the mechanism showed in `Examples/Plugins`.