Wechat mini program get wxml component from wxs file - wechat

Question

I need to get a component from a function in a wxs file
According to official documentation interactive-animation and event, when you handle an event or an observer from a wxs, a function parameter arrives ownerInstance which you can use to get any node from the wxml file
Handler Observer
WXML FILE
<wxs module="test" src="./test.wxs"></wxs>
<view id="tapTest" data-hi="Weixin" bindtap="{{test.tapName}}"> Click me! </view>
WXS FILE
function tapName(event, ownerInstance) {
console.log('tap Weixin', JSON.stringify(event))
var component = ownerInstance.selectComponent('#tapTest')
var componentHeight = component.getComputedStyle(['height']).height
//...
}
module.exports = {
tapName: tapName
}
Handler Observer
WXML FILE
<wxs module="test" src="./test.wxs"></wxs>
<view id="tapTest" change:prop="{{test.propObserver}}" prop="{{propValue}}" bindtouchmove="{{test.touchmove}}" class="movable"></view>
WXS FILE
touchmove: function(event, instance) {
console.log('log event', JSON.stringify(event))
},
propObserver: function(newValue, oldValue, ownerInstance, instance) {
console.log('prop observer', newValue, oldValue)
var component = ownerInstance.selectComponent('#tapTest')
var componentHeight = component.getComputedStyle(['height']).height
}
module.exports = {
touchmove: touchmove,
propObserver: propObserver
}
But I need to be able to get any wxml element from a function without it being an event or observer call, and to be able to read properties. For example:
WXML FILE
<wxs module="test" src="./test.wxs"></wxs>
<my-custom-component id="firstComponent">
<!-- ... -->
</my-custom-component>
<view>the height of component: {{test.getComponentHeight("firstComponent")}}</view>
wxs File
getComponentHeight: function(componentId) {
// ownerInstance NOT EXIST ....
var component = ownerInstance.selectComponent('#' + componentId)
var componentHeight = component.getComputedStyle(['height']).height
},
module.exports = {
getComponentHeight: getComponentHeight
}
I've tried putting ownerInstance as a parameter to see if it "injects" it, I've also tried putting this.selectComponent('#' + componentId) and it doesn't work either.
Please, help me!!!