What I ended up doing to get the Id of each Content type from the Sharepoint list was to use:
Text = fx ThisItem.'Content type'.Id in a Gallery Text Label Since I had records in the Sharepoint list with various content types assigned, I could deduce which Content type Id went with each ContentName.
Then, I put those Id's and ContentNames in a table as a global variable as advised, at the App level, onStart:
Set(glbContentTypes,
Table(
{Id: "AA277863BE0330970200B342B61A6D37C749A9B41C5D52B7", ContentName:"Desktops"},
{Id: "AA277863BE03309703006696FE7A12CB1E4D8F97F4CB1F417", ContentName:"Laptops"},
{Id: "AA277863BE0330970400B2DB9313202AEF4E8AB05FD62C15A", ContentName:"Servers"}
)
)
Then back in the Powerapp Gallery I can reference the Content type 'ContentName' as advised:
Text = fx LookUp(glbContentTypes, Id=ThisItem.'Content type'.Id, ContentName)
However, now I'm left wondering how to adjust my Gallery Search Filter to accommodate the 'ContentName' from that table set by the global variable?
I have (where: Tech Assets is the Sharepoint list, and glbContentTypes is the global variable):
SortByColumns(Filter([@'Tech Assets'],
(TextSearchBox1.Text in Title)
Or (TextSearchBox1.Text in 'ID Barcode')
Or (TextSearchBox1.Text in 'Building Room')
Or (TextSearchBox1.Text in 'Warranty Date')
Or (TextSearchBox1.Text in glbContentTypes.ContentName)
), "Title", If(SortDescending1, Descending, Ascending))
No errors, when adding "Or (TextSearchBox1.Text in glbContentTypes.ContentName)", but this added filter on my apps's variable's table's field's name doesn't seem to work.