Late reply, but this AnswerHub question was the first hit result on searching for it. I was searching for the same thing.
In UE4.15 (and likely any prior version) there is no specific property to set the font style (such as “Set Font Bold”). However, using the node “Set Font” of a (Text) Widget lets you enter a font name. This font name is exactly the name of the dropdown you specificy in the details panel. A bit irritating but that’s how it works. “Set Font” shouldn’t be confused with the actually font family. The Font Info structure has a Font and Font Family property.
For applying a bold and italic style of a font family having these fonts (such as Roboto):
You can receive the name of the desired font by opening the font asset or by copying the property in the details panel, right-click and choose copy. Paste it into a text editor, the content will have a sting of TypefaceFontName specificing the name. This is generally the same as the dropdown display but just in case it differs.
The standard names for the Roboto font are:
These styles are setup in the actual font asset and may differ from font to font.
I aim to make a dialogue system that parses text strings for font tags (eg. This isBold).
I don’t think the UMG widget text renderers (or Slate) does allow such thing. It was possible in UE3 but I haven’t found a documentation about a similar feature in UE4.
What you can do as a workaround. Parse the text and split it into chunks. Each chunk will be dynamically converted into single separate text widget (created on runtime) and added to a Wrap box.
So a text of “This text has a bold segment.” become:
<TextWidget>This text has a </TextWidget><TextWidget Font=“Bold”>bold</TextWidget><TextWidget> segment.</TextWidget>
This text has a bold segment.