import Vue from 'vue' import { hasFetch, normalizeError, addLifecycleHook, purifyData, createGetCounter } from '../utils' async function serverPrefetch() { if (!this._fetchOnServer) { return } // Call and await on $fetch try { await this.$options.fetch.call(this) } catch (err) { if (process.dev) { console.error('Error in fetch():', err) } this.$fetchState.error = normalizeError(err) } this.$fetchState.pending = false // Define an ssrKey for hydration this._fetchKey = this._fetchKey || this.$ssrContext.fetchCounters['']++ // Add data-fetch-key on parent element of Component const attrs = this.$vnode.data.attrs = this.$vnode.data.attrs || {} attrs['data-fetch-key'] = this._fetchKey // Add to ssrContext for window.__NUXT__.fetch <% if (debug) { %> if (this.$ssrContext.nuxt.fetch[this._fetchKey] !== undefined) { console.warn(`Duplicate fetch key detected (${this._fetchKey}). This may lead to unexpected results.`) } <% } %> this.$ssrContext.nuxt.fetch[this._fetchKey] = this.$fetchState.error ? { _error: this.$fetchState.error } : purifyData(this._data) } export default { created() { if (!hasFetch(this)) { return } if (typeof this.$options.fetchOnServer === 'function') { this._fetchOnServer = this.$options.fetchOnServer.call(this) !== false } else { this._fetchOnServer = this.$options.fetchOnServer !== false } const defaultKey = this.$options._scopeId || this.$options.name || '' const getCounter = createGetCounter(this.$ssrContext.fetchCounters, defaultKey) if (typeof this.$options.fetchKey === 'function') { this._fetchKey = this.$options.fetchKey.call(this, getCounter) } else { const key = 'string' === typeof this.$options.fetchKey ? this.$options.fetchKey : defaultKey this._fetchKey = key + getCounter(key) } // Added for remove vue undefined warning while ssr this.$fetch = () => {} // issue #8043 Vue.util.defineReactive(this, '$fetchState', { pending: true, error: null, timestamp: Date.now() }) addLifecycleHook(this, 'serverPrefetch', serverPrefetch) } }