BigQuery fails to save view that uses functions

As per the documentation https://cloud.google.com/bigquery/docs/reference/standard-sql/data-definition-language#create_function_statement , the functionality is still in Beta phase but is doable. The functions can be viewed in the same dataset it was created and the view can be created. Please share if that worked fine for you or if you have any findings which would be helpful for others.

Saving a view created with a temp function is still not supported, but what you can do is plan the SQL-query (already rolled out for the latest UI), and then save it as a table. This worked for me, but I guess it depends on the query parameters you want.

##standardSQL
## JS in SQL to extract multiple h.CDs at the same time. 
CREATE TEMPORARY FUNCTION getCustomDimension(cd ARRAY<STRUCT< index INT64, 
value STRING>>, index INT64)
RETURNS STRING
LANGUAGE js AS """
     for(var i = 0; i < cd.length; i++) {
     var item = cd[i];
     if(item.index == index) {
         return item.value
  }
}
return '';
""";

SELECT DISTINCT h.page.pagePath, getcustomDimension(h.customDimensions,20), fullVisitorId,h.page.pagePathLevel1, h.page.pagePathLevel2, h.page.pagePathLevel3, getcustomDimension(h.customDimensions,3)
FROM
`XXX.ga_sessions_*`,
UNNEST(hits) AS h
WHERE
    ### rolling timeframe
    _TABLE_SUFFIX = FORMAT_DATE('%Y%m%d',DATE_SUB(CURRENT_DATE(),INTERVAL YY DAY))
    AND h.type='PAGE'

Credit for the solution goes to https://medium.com/@JustinCarmony/strategies-for-easier-google-analytics-bigquery-analysis-custom-dimensions-cad8afe7a153

Since the issue was marked as resolved, BigQuery now supports permanents registration of UDFs. In order to use your UDF in a view, you'll need to first create it.

CREATE OR REPLACE FUNCTION `ACCOUNT-NAME11111.test.STR_TO_TIMESTAMP`
    (str STRING) 
    RETURNS TIMESTAMP AS (PARSE_TIMESTAMP('%Y-%m-%dT%H:%M:%E*SZ', str));

• Note that you must use a backtick for the function's name.
• There's no TEMPORARY in the statement, as the function will be globally registered and persisted.
• Due to the way BigQuery handles namespaces, you must include both the project name and the dataset name (test) in the function's name.

Once it's created and working successfully, you can use it a view.

create view test.test_view as
select `ACCOUNT-NAME11111.test.STR_TO_TIMESTAMP`('2015-02-10T13:00:00Z') as ts

You can then query you view directly without explicitly specifying the UDF anywhere.

select * from test.test_view