I have an object of newsfeed items like below.
[{'story_id':130,'pinned':0,....},{'story_id':131,'pinned':1,....},{'story_id':132,'pinned':0,....},{'story_id':133,'pinned':0,....}]
I need to primarily order the news stories by their story_id DESC. But if a story has the property 'pinned'=1 it needs to be first.
filtered_news_feed: function() {
var list= _.orderBy(this.feed_items, ['story_id'],'desc');
return list;
},
The above works, but how do I do pinned items first, then the rest? For some reason the below completely ignores the story_id
var list= _.orderBy(this.feed_items, ['pinned','story_id'],'desc');
Using Array#sort:
const arr = [ {'story_id':130,'pinned':0}, {'story_id':131,'pinned':1}, {'story_id':132,'pinned':0}, {'story_id':133,'pinned':0} ];
const sorted = arr.sort(
({ story_id: storyIdA, pinned: pinnedA }, { story_id: storyIdB, pinned: pinnedB }) =>
pinnedB - pinnedA || storyIdB - storyIdA
);
console.log(sorted);You can achieve this results in many ways, one of them is:
filtered_news_feed: function() {
const pinnedItems = this.feed_items.filter(item => item.pinned === 1);
const normalItems = this.feed_items.filter(item => item.pinned === 0);
return [
...pinnedItems,
_.orderBy(normalItems, ['story_id'], 'desc')
];
}
First, separate pinned items from normal items. Then return merged array with pinned items at the beginning.
Note: I used modern features of ES here. You should compile it via babel or other tool.