Improve listener logic.

[dompuiu]

Description

Changed the code so that a listener is added on document.body only once. And only if there is a rule with the Google DL Push Event.

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] I have signed the Adobe Open Source CLA.
• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[dompuiu]

On a separate note, I see you added a Custom Event polyfill for IE. But the library code is a mix of ES5 and ES6 (const is used in the code). I think you need to decide if you really want to support IE. I wouldn't. But if you decide to support it, all the code needs to be ES5. Otherwise it won't run in IE.

[brobatr]

On a separate note, I see you added a Custom Event polyfill for IE. But the library code is a mix of ES5 and ES6 (const is used in the code). I think you need to decide if you really want to support IE. I wouldn't. But if you decide to support it, all the code needs to be ES5. Otherwise it won't run in IE.

hi @dompuiu this came from an observation from Brent, so I assumed that what we have, ES6, is OK (I think IE11 does support const with limitations), but that CustomEvent is a problem. Since we removed the transpile I had given up on IE! I'll review IE11 compatibility with what we have and decide whether to remove the polyfill again or not