UpdateTextStyle Request Clearing Bold When Setting fontFamily - google-docs-api

Question

I am trying to update the font of a range of text in a Google Docs document using the API. I am trying to change just the font and not the font size or style attributes like bold or italic. So if for example I have a document with just the text below as the content:
Hello world
I want to change just the font for the word Hello but leave it the same size and still bold and italic.
I tried to accomplish this with the following code documents.batchUpdate request
{
"requests": [
{
"updateTextStyle": {
"range": {
"startIndex": 1,
"endIndex": 6
},
"textStyle": {
"weightedFontFamily": {
"fontFamily": "Times New Roman"
}
},
"fields": "weightedFontFamily"
}
}
]
}
The result is a successful response from the server but when I check the document I see it changed the font keeping the size and italic attribute, but it didn't keep the bold attribute. I have also tried this using the Google API Explorer and can reproduce the same results.
My question is how do I change the font without loosing the bold? It seems like it should be possible as it kept the italic attribute in tact. Why is bold different? Is it a bug?
My goal is to just change the font leaving the other attributes as is so I do not want to set bold or other attributes explicitly. I also don't want to have to determine the attributes before hand and reset them. That is more work and will be slower and shouldn't be necessary if italic is maintained.
I am able to do something very similar without issue in Google Sheets using a repeatCell.cell.userEnteredFormat.textFormat.fontFamily request and it maintains the bold and italic.
Thanks in advance for any insight or help.

Answer 1

How do I change the font without loosing the bold?
Answer
You have to first save the font weight and bold settings for the range of text you want to modify. There may be more then one font setting for the range. To get the font weight and bold settings for the range you must first check textRun.textStyle. If not defined there you must lookup the paragraphs namedStyleType and check it for the weight and bold settings. If not defined there you must check the NORMAL_TEXT namedStyleType. If not defined there you must use the Google Docs editor default value which for weight is 400 and bold is false.
Once you have the font info for the range you make make a requests for each different font. The request would be like the one in the original question but would set the weightedFontFamily.weight and the bold attributes based on the saved font info.
{
"requests": [
{
"updateTextStyle": {
"range": {
"startIndex": 1,
"endIndex": 6
},
"textStyle": {
"weightedFontFamily": {
"fontFamily": "Times New Roman"
"weight": savedWeight
},
"bold": savedBold
},
"fields": "weightedFontFamily"
}
}
]
}
Why is bold different?
Answer
The Google Docs API uses weightedFontFamily where the weight sub-attribute defaults to 400 and not the current font weight. The bold setting just increases the weight, so bold and weight are linked. There is no current way in the API to set just the font leaving weight/bold alone.
Is it a bug?
Answer
Based on a reply from #Tanaike I have reported the issue to Google via the Google Issue Tracker (https://issuetracker.google.com/165029692). They informed me it was working as intended.