Margins on children of ConstraintLayout do not display?

Question

I'm using Android's new ConstraintLayout for my app and I've been having problems having margins on elements show up. For reference I'm using the following line in my gradle file for ConstraintLayout com.android.support.constraint:constraint-layout:1.0.0-beta4. The code in my layout is below.

<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingStart="@dimen/activity_horizontal_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/post_vertical_padding"
    android:paddingEnd="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingBottom="@dimen/post_vertical_padding"
    android:background="?android:attr/selectableItemBackground">

    <TextView
        style="@style/TitleText"
        android:id="@+id/post_type"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="@dimen/post_line_vertical_padding"
        android:layout_marginEnd="@dimen/post_type_horizontal_padding"
        android:layout_marginRight="@dimen/post_type_horizontal_padding"
        app:layout_constraintLeft_toRightOf="@id/poster_profile_pic"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/poster_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintLeft_toRightOf="@id/post_type"
        app:layout_constraintBaseline_toBaselineOf="@id/post_type" />

</android.support.constraint.ConstraintLayout>

Answer 1

1. If you use paddingStart, no need for paddingLeft
2. app:layout_constraintLeft_toRightOf="@id/poster_profile_pic" there is no image view here with id poster_profile_pic
3. android:layout_marginBottom will not work unless you include constraintBottom_toBottomOf="parent"
4. android:layout_marginRight should be android:layout_marginLeft but in poster_name because poster_name has app:layout_constraintLeft_toRightOf="@id/post_type"