[WEEX-241][iOS] add WXVideoComponent "poster" attribute

[xuyouyang]

• [iOS] add WXVideoComponent poster feature and add support "poster" attribute to

feature:241

[weex-bot]

	Messages
📖	has no android file changed.
📖	android test finished.

Generated by 🚫 dangerJS

[acton393]

hi, @xuyouyang what's the "poster" feature， is it the paused picture about player display?

[xuyouyang]

NO.
The poster attribute specifies an image to be shown while the video is downloading, or until the user hits the play button. If this is not included, the first frame of the video will be used instead.
You can see this "https://www.w3schools.com/tags/att_video_poster.asp"
It is a attribute in HTML <video> tag
@acton393

[acton393]

@xuyouyang I got it and find the w3c rules about it : https://developer.mozilla.org/en-US/docs/Web/HTML/Element/video

thanks, we can make it more standard by add more attributes and styles, what about Android?
documentation will be updated when this merged

[acton393]

How about lazy load when front-end developer specify the poster attributes

[xuyouyang]

good ideal! I will modify this later.

[acton393]

@xuyouyang as the development process shows, we need create a jira issue in apache, and format your pull request title and commit log.

I have created a jira issue for this feature, and the issue id is WEEX-241, the issue address is https://issues.apache.org/jira/browse/WEEX-241

what you need to do next is to update the title as the following format
[WEEX-jiraId][iOS/Android] summary

thanks

[xuyouyang]

OK. Thank you very much! @acton393

[acton393]

@xuyouyang It look good to me and it will be accepted, thank you.
It would be better if Android player can support poster attributes.

[xuyouyang]

@acton393 Ha, it's sorry that I am not familiar with Android develop very much.😂