Created attachment 112003 [details]
Said file

With the attached file, when writing on the field i get
file:///usr/lib/qt/qml/QtQuick/Controls/Styles/Plasma/TextFieldStyle.qml:46:17: QML QQuickItem: Binding loop detected for property "implicitHeight"
file:///usr/lib/qt/qml/QtQuick/Controls/Styles/Plasma/TextFieldStyle.qml:46:17: QML QQuickItem: Binding loop detected for property "implicitHeight"
file:///usr/lib/qt/qml/QtQuick/Controls/Styles/Plasma/TextFieldStyle.qml:46:17: QML QQuickItem: Binding loop detected for property "implicitHeight"
file:///usr/lib/qt/qml/QtQuick/Controls/Styles/Plasma/TextFieldStyle.qml:46:17: QML QQuickItem: Binding loop detected for property "implicitHeight"

Which doesn't make any sense since i'm not changing the height.

Putting the code here for quick reading too

import QtQuick 2.6
import org.kde.plasma.components 2.0 as PlasmaComponents

Item {
    width: 800
    height: 600

    PlasmaComponents.TextField {
        width: text !== "" ? 500 : 250
    }
}