[
https://issues.apache.org/jira/browse/AVRO-1245?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13659307#comment-13659307
]
Scott Carey commented on AVRO-1245:
-----------------------------------
Another possibility is to do it all at builder construction time -- there is
less to do when you are guaranteed a clean-slate, and the existing record must
be walked at least once for a deep copy anyway.
{code}
boolean replaceNullsWithDefaults = true;
boolean replaceEmptyStringsWithDefaults = true;
User.newBuilder(thirdPartyRedord, replaceNullsWithDefaults,
replaceEmptyStringsWithDefaults);
{code}
This bears resemblance to one of our other ideas -- that there is no 'read' and
'write', only 'from' and 'to' -- a deep copy is like serializing 'from' one
object 'to' another (rather than to binary, etc). Replacing values is a
special case of schema resolution when translating data from one object to
another.
> Add Merging Functionality to Generated Builders
> -----------------------------------------------
>
> Key: AVRO-1245
> URL: https://issues.apache.org/jira/browse/AVRO-1245
> Project: Avro
> Issue Type: Improvement
> Components: java
> Affects Versions: 1.7.3
> Environment: Linux Mint 32-bit, Java 7, Avro 1.7.3
> Reporter: Sharmarke Aden
> Priority: Minor
>
> Suppose I have a record with the following schema and default values:
> {code}
> {
> "type": "record",
> "namespace": "test",
> "name": "User",
> "fields": [
> {
> "name": "user",
> "type": ["null", "string"],
> "default": null
> },
> {
> "name": "privacy",
> "type": [
> {
> "type": "enum",
> "name": "Privacy",
> "namespace": "test",
> "symbols": ["Public", "Private"]
> },
> "null"
> ],
> "default": "Private"
> }
> ]
> }
> {code}
> Now suppose I have a record supplied to me by a third party whose privacy
> field value is null. Currently if you call
> "Builder.newBuilder(thirdPartyRecord)" it simply creates a new record with
> same values as the source record (privacy is null in the newly created
> builder).
> It's very important that the privacy value be set and so ideally I would like
> to perform a merge to mitigate any issues with default values being absent in
> the source record. I would like to propose that a new enhancement be added to
> the Builder to support merging of a source record to a new record. Perhaps
> something like this:
> {code}
> // recordWithoutDefaults record passed in.
> User.Builder builder = User.newBuilder();
> //ignore null values in the source record if the schema has a default
> //value for the field
> boolean ignoreNull = true;
> //ignore empty string values in the source record for string field
> //types with default field values
> boolean ignoreEmptyString = true;
> //while this is simple and useful in my use-case perhaps there's a
> //better/refined way of supporting veracious merging models
> builder.merge(recordWithoutDefaults, ignoreNull, ignoreEmptyString);
> {code}
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
