vue-wp/vue-theme/src/pages/list.vue

<template lang="pug">
.page--list.f-col.between
    article.f-grow

        header.center.t-up
            .title.f-row
                h3 {{ type }} list
                span(v-if="sortBy")
                    h3 &nbsp;sorted {{ sortBy.replace('-', ' ') }}

            h3(v-if="!loaded") loading...
            .content(
                v-else-if="allPagesLoaded && type && allPages[type]"
                v-html="allPages[type].content"
            )

        ul.posts.f-col(v-if="posts && loaded" :class="{ 'is-grid': grid }")
            li(v-for="(post, i) in posts" :key="post.slug").post.shadow
                card(:content="post" :type="type" :wide="isWide")
        
        //- Important: Do NOT remove this! Required for intersection observer
        footer
            p(v-if="loadingFetched") loading more {{ type }}...
            p(v-if="showMeta") {{ `${type} count: ${Object.values(posts).length}` }}
            p(v-if="showMeta") {{ `show sidebar: ${sidebar}` }}

    sidebar(v-if="sidebar" :type="`${type}`" layout="list")
</template>

<script>
import featuredImage from '@/components/featured-image'
import card from '@/components/card'
import sidebar from '@/components/sidebars/sidebar'
import { postTypeGetters, scrollTop, heroUtils } from './mixin-post-types'

import { postTypes, sortTypes, convertTitleCase } from '@/utils/helpers'

const TIMEOUT = 1
const INTERSECT_SELECTOR = '.page--list > article footer'

const wideTypes = ['event', 'exhibition']
const gridTypes = ['episode', 'artist']
const sansSidebarTypes = ['episode']

export default {
    components: { sidebar, featuredImage, card },
    mixins: [postTypeGetters, scrollTop, heroUtils],
    data() {
        return {
            showMeta:false,
            page: 0,
            perPage: 21,
            keepFetching: true,
            loadingFetched: false,
            observer: null
        }
    },
    computed: {
        grid() {
            return gridTypes.includes(this.type)
        },
        isWide() {
            return wideTypes.includes(this.type)
        },
        sidebar() {
            return !sansSidebarTypes.includes(this.type)
        },
        type() {
            // Checks for type and fixes Episodes route edge case
            return this.$route.params.type
        },
        sortBy() {
            return this.$route.params.sortBy
        },
        pType() {
            if(!this.type) return
            return `${convertTitleCase(this.type)}s`
        },
        loaded() {
            if (!this.pType) return
            return this[`all${this.pType}Loaded`]
        },
        posts() {
            if (!this.pType) return
            return this[`all${this.pType}`]
        },
        shouldLoadAllAtOnce() {
            return this.type == 'episode' || this.type == 'artist' && this.sortBy == sortTypes.material
        }
    },
    methods: {
        async loadMorePosts(shouldClear) {
            if(shouldClear) this.$store.commit(`CLEAR_${this.pType.toUpperCase()}`)
            if(!this.keepFetching) return console.warn('nothing left to fetch...')

            try {
                this.loadingFetched = true
                this.page++

                const res = await this.getPosts(
                    {
                        limit: this.shouldLoadAllAtOnce ? -1 : this.perPage,
                        page: this.page
                    },
                    this.shouldLoadAllAtOnce ? 'All' : 'More'
                )

                this.loadingFetched = false
                
                // Stop trying to load more posts
                if(res && !res.length || this.shouldLoadAllAtOnce) {
                    this.keepFetching = false
                    if(!res.length) console.warn(`Empty response for ${this.type}:`, res.length)
                    if(this.shouldLoadAllAtOnce) console.warn(`Fetched all responses for ${this.type}:`, res.length)
                }
            } catch (err) { console.error(err) }
        },
        async getPosts(params, dispatchType) {
            if(!this.type) throw `post type: ${this.type} not found...`
            
            let res = []
            // We always grab all pages on hero init so no need to do it here
            if(this.pType && this.keepFetching && this.type != 'page') {
                res = await this.$store.dispatch(
                    `get${dispatchType}${this.pType}`,
                    { sortType: this.sortBy, params }
                )
            }
            return res
        },
        async getPage(type) {
            await this._getAllIfNotLoaded('page', this.$store)
            if(!this.allPages) throw 'no pages in state'
            const page = this.allPages.filter(page => page.slug == `${type}s`)[0]
            if(!page) throw `No page: ${type} found. Cannot set hero.`
            return page
        },
        // _setHeroInfo(post) {} from mixin
        // _clearHero(store) {} from mixin
        async checkAndSetHero(type) {
            this._clearHero(this.$store)
            try {
                const page = await this.getPage(type)
                // We always set a hero no matter what
                // Because the hero component will deal
                // with how to render based on hero.url
                this.$store.commit('SET_HERO', this._setHeroInfo(page))
            } catch (err) {
                console.error(err)
            }
        },
        setIntersectionLoader() {
            // KeepFetching is UNSET for certain post types and sort types in `loadMorePosts()`
            if(!this.keepFetching) return console.warn('Cannot setup intersection handler keepFetching is set false')
            
            // Always unset before setting the intersection loader
            this.unsetIntersectionLoader()

            // console.warn('Setting interesection loader...')
            this.observer = new IntersectionObserver(entries => {
                entries.forEach(entry => {
                    if (!entry.isIntersecting || this.loadingFetched) return
                    setTimeout(this.loadMorePosts, TIMEOUT)
                })
            }, { threshold: 0.80 })
            this.observer.observe(document.querySelector(INTERSECT_SELECTOR))
        },
        unsetIntersectionLoader() {
            const footerEl = document.querySelector(INTERSECT_SELECTOR)
            try {
                if(!footerEl) throw `cannot unset intersection handler missing el: ${footerEl}`
                if(!this.observer) throw `cannot unset intersection handler missing observer: ${this.observer}`
                this.observer.unobserve(footerEl)
                this.observer.disconnect()
            } catch (error) { console.error(error) }
        },
        initPostList() {
            this.page = 0
            this.keepFetching = true

            this.checkAndSetHero(this.type)

            // Clear any preloaded posts (from home, etc.)
            this.loadMorePosts(true)
            this.setIntersectionLoader()
        }
    },
    watch: {
        // This only fires navigating from
        // a list page, to another list page
        // and the post type has changed
        type(newType) {
            if(!postTypes.includes(newType)) return console.warn('Type not valid...')

            // Ignore types with presorts so the sortBy watcher can handle them
            const ignore = ['event', 'exhibition', 'artist']
            if(ignore.includes(newType)) return
            this.initPostList()
        },
        sortBy(newSort) {
            if(!Object.values(sortTypes).includes(newSort)) return
            this.initPostList()
        }
    },
    mounted() {
        // This only fires navigating from a non-list page > list page
        this.initPostList()
    },
    beforeDestroy() {
        this.unsetIntersectionLoader()
    }
}
</script>

<style lang="postcss">
// prettier-ignore
@import '../sss/variables.sss'
@import '../sss/theme.sss'
.page--list article
    > header
        padding: 1em
        > h1
            margin: 0
        > .content
            padding: 0
            width: 100%
    > footer
        padding: $ms-0

    /* posts not grid list */
    .posts
        list-style: none
        grid-gap: $ms--2
        .post
            width: 100%

    /* posts in grid list */
    .posts.is-grid
        width: 100%
        display: grid
        grid-template-columns: repeat(1, 1fr)
        align-items: start
        /* This is important for how the grid lines up to the page */
        justify-content: right 
        .post img
            width: 100%

@media (min-width: $medium)
    .page--list
        &.f-col
            flex-direction: row
        > article
            margin: 0 $ms--2 0 0
            .posts.is-grid
                grid-template-columns: repeat(3, 1fr)
</style>