[Issue 797]Filter tableview message for empty key and add example for tableview

[liangyuanpeng]

(If this PR fixes a github issue, please add Fixes #<xyz>.)

Fixes #797

Motivation

Explain here the context, and why you're making that change. What is the problem you're trying to solve.

Modifications

• Add example for tableview
• Filter tableview message for empty key

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API: (yes / no)
• The schema: (yes / no / don't know)
• The default values of configurations: (yes / no)
• The wire protocol: (yes / no)

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / GoDocs / not documented)
• If a feature is not applicable for documentation, explain why?
• If a feature is not documented yet in this PR, please create a followup issue for adding the documentation

[pgier]

LGTM

[pgier]

Minor suggestion to just return if the key is empty instead of nesting in the if.

Suggested change

	if msg.Key() != "" {
	if msg.Key() == "" {
	return
	}

[merlimat]

@liangyuanpeng The change looks good, can you also expand the unit test to verify the key is delete from the table view?

[liangyuanpeng]

@merlimat @pgier Resolved review conment and add test, PTAL, Thanks.

[liangyuanpeng]

Closed by not review.