You can create a file on SharePoint using a dynamic url/library, but you can't update the properties using a dynamic function.
For example if you need to create a file in different SharePoint libraries depending on the content, you need to create a switch with x (the number of libraries) update file properties functions.
I agree: some minimal properties should be available at design time
For updating/creating items, all properties should be available during design time.If the specific library is unknown during design time, then let the dev supply the column names and values. It's the dev's job to know those things. If there's a column name or datatype mismatch during runtime, then just throw an error saying that.Having to use the switch statement with duplicate actions is an incredibly frustrating and error-prone workaround.
I agree, this should be possible, so frustrating it is currently not possible.
We need all file/item properties available even if they are parameterized. Just do it like all the 'low code' tooling out there is doing it: If a variable is supplied that can not be resolved at design time, show a popup to have the user enter the actual resolvable values and then have the action resolve that value and work on it at design time.
The one workaround for now is to resort to the mess of doing it with the REST calls with JSON, but without copy-paste options for actions in Flow (https://powerusers.microsoft.com/t5/Flow-Ideas/Copy-action-time-saver/idi-p/30822), this is an absolute no-go as it is time-intensive, error prone and non-repeatable through DTAP especially if you have to repeat the same kind of constructs within a singular flow. It also defeats the whole 'low-code' angle Flow was aiming for, because be honest JSON is not meant as a readable format.
#April2019: Flow has to mature a bit more to make it actually useful for larger, real life projects.
We have the same requirement. This is for a client's payroll requirement where all payslips are emailed in with the relevant HR number on the subject line - employee quantity changing etc, completely impractical to manually do this.
We can extract the attached payslip file from the email, lookup the HR number in a list and find out where the employee's private HR library is and create the file there but we need to set some custom columns which without the update properties accepting dynamic parameters for site and library makes it impossible. What's frustrating is that the update properties action even works by using the variable for the site and other variable for the library name with the item id of the created item, it just won't let us set the properties themselves. I've even tried hardcoding the site and library to a single item then exporting the Flow to view the json, then editing in the appropriate 'body' section of json into an export of the dynamic version of the Flow and realistically that should work but I can't get the Flow to re-import. If anyway has any bright ideas on if this can fly as a workaround and what I need to do to get the import to be successful then reply.