Object Page with blocks - sapui5

Question

I've got this ObjectPageLayout:
request.view.xml
<ObjectPageLayout>
<headerTitle>
...
</headerTitle>
<headerContent>
...
</headerContent>
<sections>
<ObjectPageSection
mode="Collapsed">
<subSections>
<ObjectPageSubSection title="fooBlock">
<blocks>
<blockdetail:FormBlock columnLayout="auto" /> <!-- MY BLOCK -->
</blocks>
</ObjectPageSubSection>
</subSections>
</ObjectPageSection>
</sections>
</ObjectPageLayout>
FormBlockCollapsed.view.xml (MY BLOCK)
<mvc:View xmlns:f="sap.ui.layout.form" xmlns:mvc="sap.ui.core.mvc"
xmlns:core="sap.ui.core" xmlns:l="sap.ui.layout" xmlns="sap.m"
controllerName="NAMESPACE.blocks.DetailsBlockCommon">
<FlexBox>
<HBox>
<VBox>
<f:SimpleForm >
<f:content>
<CheckBox class="sapUiSmallMarginBegin sapUiSmallMarginTop" id="myCheckbox" />
</f:content>
</f:SimpleForm>
</VBox>
</HBox>
</FlexBox>
...
</mvc:View>
So far, everything is fine. My Object page looks good a the checkbox is shown.
In my Controller request.controller.js i want to validate the checkbox in FormBlockCollapsed.view.xml
validateBlockForm: function(format){
console.log( oView.byId("myCheckbox").checked() ); //oView.byId("myCheckbox") is undefined
}
But i've no access to my checkbox in the block.
Cannot read property 'checked' of undefined
Further infos
FormBlock.js
sap.ui.define(['sap/uxap/BlockBase'], function (BlockBase) {
"use strict";
var MultiViewBlock = BlockBase.extend("NAMESPACE.blocks.FormBlock", {
metadata: {
views: {
Collapsed: {
viewName: "NAMESPACE.blocks.FormBlockCollapsed",
type: "XML"
}
}
}
});
return MultiViewBlock;
}, true);
DetailBlockCommon.js
sap.ui.define([
"NAMESPACE/controller/BaseController"
], function (BaseController) {
"use strict";
return BaseController.extend("NAMESPACE.blocks.DetailsBlockCommon", {
});
});

Answer 1

You can access the elements in a section by having the block's id and element's id.
First we have to define an id for the block in the xml view:
<blocks>
<blockdetail:FormBlock id="formBlock" columnLayout="auto" /> <!-- MY BLOCK -->
</blocks>
Then we generate the id of the elements like the following in the view controller. The state of the art here is to add -Collapsed-- as part of the id that adds by SAPUI5 to sections elements.
var sFieldId = this.getView().createId("formBlock") +
"-Collapsed--myCheckbox";
var oCheckbox = sap.ui.getCore().byId(sFieldId);

Answer 2

Check if oView is defined.
you can easily get it by this.getView()