#255 - implement autocomplete in non post forms

#255 (closed) - implement AutoCompleteComponent and make name & bio fields auto-complete

src/components/autocomplete_input/autocomplete_input.js

+import Completion from '../../services/completion/completion.js'
+import { take, filter, map } from 'lodash'
+
+const AutoCompleteInput = {
+  props: [
+    'id',
+    'classObj',
+    'value',
+    'placeholder',
+    'autoResize',
+    'multiline',
+    'drop',
+    'dragoverPrevent',
+    'paste',
+    'keydownMetaEnter',
+    'keyupCtrlEnter'
+  ],
+  components: {},
+  mounted () {
+    this.autoResize && this.resize(this.$refs.textarea)
+    const textLength = this.$refs.textarea.value.length
+    this.$refs.textarea.setSelectionRange(textLength, textLength)
+  },
+  data () {
+    return {
+      caret: 0,
+      highlighted: 0,
+      text: this.value
+    }
+  },
+  computed: {
+    users () {
+      return this.$store.state.users.users
+    },
+    emoji () {
+      return this.$store.state.instance.emoji || []
+    },
+    customEmoji () {
+      return this.$store.state.instance.customEmoji || []
+    },
+    textAtCaret () {
+      return (this.wordAtCaret || {}).word || ''
+    },
+    wordAtCaret () {
+      const word = Completion.wordAtPosition(this.text, this.caret - 1) || {}
+      return word
+    },
+    candidates () {
+      const firstchar = this.textAtCaret.charAt(0)
+      if (firstchar === '@') {
+        const query = this.textAtCaret.slice(1).toUpperCase()
+        const matchedUsers = filter(this.users, (user) => {
+          return user.screen_name.toUpperCase().startsWith(query) ||
+            user.name && user.name.toUpperCase().startsWith(query)
+        })
+        if (matchedUsers.length <= 0) {
+          return false
+        }
+        // eslint-disable-next-line camelcase
+        return map(take(matchedUsers, 5), ({screen_name, name, profile_image_url_original}, index) => ({
+          // eslint-disable-next-line camelcase
+          screen_name: `@${screen_name}`,
+          name: name,
+          img: profile_image_url_original,
+          highlighted: index === this.highlighted
+        }))
+      } else if (firstchar === ':') {
+        if (this.textAtCaret === ':') { return }
+        const matchedEmoji = filter(this.emoji.concat(this.customEmoji), (emoji) => emoji.shortcode.startsWith(this.textAtCaret.slice(1)))
+        if (matchedEmoji.length <= 0) {
+          return false
+        }
+        return map(take(matchedEmoji, 5), ({shortcode, image_url, utf}, index) => ({
+          screen_name: `:${shortcode}:`,
+          name: '',
+          utf: utf || '',
+          // eslint-disable-next-line camelcase
+          img: utf ? '' : this.$store.state.instance.server + image_url,
+          highlighted: index === this.highlighted
+        }))
+      } else {
+        return false
+      }
+    }
+  },
+  methods: {
+    setCaret ({target: {selectionStart}}) {
+      this.caret = selectionStart
+    },
+    cycleBackward (e) {
+      const len = this.candidates.length || 0
+      if (len > 0) {
+        e.preventDefault()
+        this.highlighted -= 1
+        if (this.highlighted < 0) {
+          this.highlighted = this.candidates.length - 1
+        }
+      } else {
+        this.highlighted = 0
+      }
+    },
+    cycleForward (e) {
+      const len = this.candidates.length || 0
+      if (len > 0) {
+        if (e.shiftKey) { return }
+        e.preventDefault()
+        this.highlighted += 1
+        if (this.highlighted >= len) {
+          this.highlighted = 0
+        }
+      } else {
+        this.highlighted = 0
+      }
+    },
+    replace (replacement) {
+      this.text = Completion.replaceWord(this.text, this.wordAtCaret, replacement)
+      const el = this.$el.querySelector('textarea')
+      el.focus()
+      this.caret = 0
+    },
+    replaceCandidate (e) {
+      const len = this.candidates.length || 0
+      if (this.textAtCaret === ':' || e.ctrlKey) { return }
+      if (len > 0) {
+        e.preventDefault()
+        const candidate = this.candidates[this.highlighted]
+        const replacement = candidate.utf || (candidate.screen_name + ' ')
+        this.text = Completion.replaceWord(this.text, this.wordAtCaret, replacement)
+        const el = this.$el.querySelector('textarea') || this.$el.querySelector('input')
+        el.focus()
+        this.caret = 0
+        this.highlighted = 0
+      }
+    },
+    resize (e) {
+      const target = e.target || e
+      if (!(target instanceof window.Element)) { return }
+      const vertPadding = Number(window.getComputedStyle(target)['padding-top'].substr(0, 1)) +
+            Number(window.getComputedStyle(target)['padding-bottom'].substr(0, 1))
+      // Auto is needed to make textbox shrink when removing lines
+      target.style.height = 'auto'
+      target.style.height = `${target.scrollHeight - vertPadding}px`
+      if (target.value === '') {
+        target.style.height = null
+      }
+    }
+  }
+}
+
+export default AutoCompleteInput