paper-chip-input.html

<link rel="import" href="../polymer/polymer-element.html">
<link rel="import" href="../polymer/lib/elements/dom-if.html">
<link rel="import" href="../polymer/lib/elements/dom-repeat.html">
<link rel="import" href="./paper-chip.html">
<link rel="import" href="../iron-input/iron-input.html">
<link rel="import" href="../iron-flex-layout/iron-flex-layout.html">
<link rel="import" href="../paper-input/paper-input-behavior.html">
<link rel="import" href="../paper-input/paper-input-container.html">
<link rel="import" href="../paper-input/paper-input-error.html">
<link rel="import" href="../paper-input/paper-input-char-counter.html">
<link rel="import" href="../paper-item/paper-icon-item.html">
<link rel="import" href="../paper-item/paper-item.html">
<link rel="import" href="../paper-listbox/paper-listbox.html">
<link rel="import" href="../paper-material/paper-material.html">
<link rel="import" href="../paper-ripple/paper-ripple.html">
<link rel="import" href="../paper-styles/default-theme.html">

<dom-module id="paper-chip-input">
    <template>
        <style>
            :host {
                display: block;

                -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
                -webkit-tap-highlight-color: transparent;

                --paper-input-container-input: {
                    overflow: hidden;
                    white-space: nowrap;
                    text-overflow: ellipsis;
                    max-width: 100%;
                    box-sizing: border-box;
                    cursor: pointer;
                };

                @apply --paper-dropdown-menu;
                width: 100%;
            }

            :host([focused]) {
                outline: none;
            }

            :host([hidden]) {
                display: none !important;
            }

            :host([noline]) {
                --paper-input-container-underline: {
                    display: none;
                };
                --paper-input-container-underline-focus: {
                    display: none;
                };
                --paper-input-container-underline-disabled: {
                    display: none;
                };
            }

            :host([no-label-float]) #label {
                top: 22px;
            }

            div[container] {
                @apply --layout;
                @apply --layout-wrap;
            }

            iron-input {
                @apply --layout-flex-auto;
                max-width: 100%;
            }

            input {
                position: relative; /* to make a stacking context */
                outline: none;
                box-shadow: none;
                padding: 0;
                width: 100%;
                max-width: 100%;
                background: transparent;
                border: none;
                color: var(--paper-input-container-input-color, var(--primary-text-color));
                -webkit-appearance: none;
                text-align: inherit;
                vertical-align: bottom;

                /* Firefox sets a min-width on the input, which can cause layout issues */
                min-width: 0;

                @apply --paper-font-subhead;
                @apply --paper-input-container-input;

                line-height: 32px;
            }

            input::-webkit-outer-spin-button,
            input::-webkit-inner-spin-button {
                @apply --paper-input-container-input-webkit-spinner;
            }

            input::-webkit-clear-button {
                @apply --paper-input-container-input-webkit-clear;
            }

            input::-webkit-input-placeholder {
                color: var(--paper-input-container-color, var(--secondary-text-color));
            }

            input:-moz-placeholder {
                color: var(--paper-input-container-color, var(--secondary-text-color));
            }

            input::-moz-placeholder {
                color: var(--paper-input-container-color, var(--secondary-text-color));
            }

            input::-ms-clear {
                @apply --paper-input-container-ms-clear;
            }

            input:-ms-input-placeholder {
                color: var(--paper-input-container-color, var(--secondary-text-color));
            }

            label {
                pointer-events: none;
                line-height: 32px;
            }

            paper-input-container {
                @apply --layout-wrap;
            }

            paper-ripple {
                top: 12px;
                left: 0;
                bottom: 8px;
                right: 0;

                @apply --paper-dropdown-menu-ripple;
            }

            paper-material {
                position: absolute;
                display: block;
                max-height: var(--paper-chip-input-autocomplete-height, 300px);
                overflow-y: auto;
                background: var(--paper-chip-input-autocomplete-background, white);
                z-index: 1;
                white-space: nowrap;
                text-overflow: ellipsis;
                width: 100%;
                box-sizing: border-box;
                cursor: pointer;
            }

            paper-item.iron-selected {
                font-weight: inherit;
            }

            paper-chip {
                margin: 0 4px 4px 0;
            }

            [hidden] {
                display: none;
            }
        </style>


        <paper-input-container id="container" no-label-float="[[noLabelFloat]]" always-float-label="[[_computeAlwaysFloatLabel(alwaysFloatLabel,placeholder,values.length)]]"
            auto-validate$="[[autoValidate]]" disabled$="[[disabled]]" invalid="[[invalid]]">

            <slot name="prefix" slot="prefix"></slot>

            <label hidden$="[[_computeLabelVisibility(noLabelFloat,label,values.length)]]" aria-hidden="true" for="input" slot="label">[[label]]</label>

            <div container slot="input">
                <dom-repeat items="[[values]]" as="value">
                    <template>
                        <paper-chip value="[[value]]" on-remove="_removeChip" removable single-line>
                            <template is="dom-if" if="[[_lookupHasIcon(value)]]">
                                <iron-icon icon="[[_lookupIcon(value)]]" src="[[_lookupIconSrc(value)]]" slot="icon"></iron-icon>
                            </template>
                            <span slot="label" class="label">[[_lookupLabel(value)]]</span>
                        </paper-chip>
                    </template>
                </dom-repeat>
                <iron-input bind-value="{{stagedValue}}" id="input" maxlength$="[[maxlength]]" allowed-pattern="[[allowedPattern]]"
                    invalid="{{invalid}}" validator="[[validator]]">
                    <input id="nativeInput" aria-labelledby$="[[_ariaLabelledBy]]" aria-describedby$="[[_ariaDescribedBy]]" disabled$="[[disabled]]"
                        title$="[[title]]" type$="[[type]]" pattern$="[[pattern]]" required$="[[required]]" autocomplete$="[[autocomplete]]"
                        autofocus$="[[autofocus]]" inputmode$="[[inputmode]]" minlength$="[[minlength]]" maxlength$="[[maxlength]]"
                        min$="[[min]]" max$="[[max]]" step$="[[step]]" name$="[[name]]" placeholder$="[[placeholder]]" readonly$="[[readonly]]"
                        list$="[[list]]" size$="[[size]]" autocapitalize$="[[autocapitalize]]" autocorrect$="[[autocorrect]]" on-change="_onChange"
                        tabindex$="[[tabIndex]]" autosave$="[[autosave]]" results$="[[results]]" accept$="[[accept]]" multiple$="[[multiple]]">
                </iron-input>
            </div>

            <slot name="suffix" slot="suffix"></slot>

            <template is="dom-if" if="[[errorMessage]]">
                <paper-input-error aria-live="assertive" slot="add-on">[[errorMessage]]</paper-input-error>
            </template>

            <template is="dom-if" if="[[charCounter]]">
                <paper-input-char-counter slot="add-on"></paper-input-char-counter>
            </template>

        </paper-input-container>

        <template is="dom-if" if="[[autocomplete]]">
                <paper-material id="tips" elevation="1" hidden$=[[hidden]]>
                    <paper-listbox tabindex="0" id="list">
                        <dom-repeat items="[[_source]]">
                            <template>
                                <paper-icon-item tabindex="0" value="[[_computeValue(item)]]" label-text="[[_computeLabel(item)]]" icon="[[_computeIcon(item)]]" icon-src="[[_computeIconSrc(item)]]" on-tap="_select">
                                     <template is="dom-if" if="[[_hasIcon(item)]]">
                                         <iron-icon icon="[[_computeIcon(item)]]" src="[[_computeIconSrc(item)]]" slot="item-icon"></iron-icon>
                                     </template>
                                     [[_computeLabel(item)]]
                                     <paper-ripple></paper-ripple>
                                </paper-icon-item>
                            </template>
                        </dom-repeat>
                    </paper-listbox>
                </paper-material>
        </template>

    </template>
    <script>
        class PaperChipInput extends
            Polymer.mixinBehaviors(Polymer.IronA11yKeysBehavior,
                Polymer.mixinBehaviors(Polymer.PaperInputBehavior, Polymer.Element)) {

            static get is() {
                return "paper-chip-input"
            }

            static get properties() {
                return {
                    stagedValue: {
                        type: String,
                        notify: true
                    },
                    displayProperty: {
                        type: String,
                        value: "label"
                    },
                    valueProperty: {
                        type: String,
                        value: "value"
                    },
                    iconProperty: {
                        type: String,
                        value: "icon"
                    },
                    iconSrcProperty: {
                        type: String,
                        value: "iconSrc"
                    },
                    hidden: {
                        type: Boolean,
                        value: true
                    },
                    label: {
                        type: String,
                        value: "Tags"
                    },
                    values: {
                        type: Array,
                        notify: true,
                        value: () => []
                    },
                    datasource: {
                        type: Array,
                        value: () => []
                    },
                    _source: {
                        type: Array,
                        value: () => []
                    },
                    _hasValues: {
                        type: Boolean
                    },
                    _hasContent: {
                        type: Boolean
                    },
                    autocomplete: {
                        type: Boolean
                    },
                    enterKeys: {
                        type: Array,
                        value: () => ["enter"]
                    },
                    filter: {
                        type: Function,
                        value: function () {
                            return (data, value) =>
                                data.filter(
                                    (item) => this._computeLabel(item).toLowerCase().startsWith(value.toLowerCase())
                                )
                        }
                    }
                }
            }

            static get observers() {
                return [
                    "_onValuesChanged(values, values.splices)"
                ];
            }

            get keyBindings() {
                return {
                    "backspace": "_remove",
                    "esc": "_hideTips"
                }
            }

            _grabChips() {
                const children = this.getEffectiveChildren()
                if (children.length > 0) {
                    for (const index in children) {
                        const el = children[index]
                        if (el instanceof PaperChip && el.value !== undefined) {
                            const item = {
                                [this.displayProperty]: el.label,
                                [this.valueProperty]: el.value,
                                [this.iconProperty]: el.icon,
                                [this.iconSrcProperty]: el.iconSrc
                            }

                            this.push("datasource", item)
                            this._pushChipByValue(el.value)
                            el.parentElement.removeChild(el)
                        }
                    }
                }
            }

            _onIronInputReady() {
                if (this.inputElement &&
                    this._typesThatHaveText.indexOf(this.inputElement.inputElement.type) !== -1) {
                    this.alwaysFloatLabel = true
                }
                // Only validate when attached if the input already has a value.
                if (!!this.inputElement.bindValue) {
                    this.$.container._handleValueAndAutoValidate(this.inputElement);
                }
            }

            _onFocusout() {
                if (this.autocomplete && !this.hidden) {
                    this._hideTips()
                }
            }

            _computeLabelVisibility(noLabelFloat, label, len) {
                return !label || (noLabelFloat && len > 0)
            }

            _computeAlwaysFloatLabel(alwaysFloatLabel, placeholder, len) {
                return placeholder || alwaysFloatLabel || len > 0
            }

            _computeHasContent(hasValues) {
                this._hasContent = this._hasValues
            }

            _add() {
                if (!this.validate())
                    return
                if (!this.autocomplete) {
                    this._pushChip()
                }
            }

            _remove(evt) {
                // path is the array of nodes through which event will pass...
                //
                // this check avoids to run _remove when press backspace key when a chip is focused.
                // In that case the event _removeChip has to take place
                if (this.$.nativeInput === evt.detail.keyboardEvent.composedPath()[0]) {
                    if (this.inputElement.value === "" && this.values.length > 0) {
                        var index = this.values.length
                        var value = this.values[index - 1]
                        this._popChip()
                        this.dispatchEvent(new CustomEvent("chip-removed", { detail: { index: index - 1, value: value } }))
                    }
                }
            }

            connectedCallback() {
                super.connectedCallback()

                this._boundOnIronInputReady = this._onIronInputReady.bind(this)

                this._boundOnFocusout = this._onFocusout.bind(this)

                const input = this.inputElement

                input.addEventListener("iron-input-ready", this._boundOnIronInputReady)

                input.addEventListener("input", (event) => {
                    this._hasContent = (this._hasValues || input.value || input.value === 0) ? true : false
                })

                input.addEventListener("keydown", (event) => {
                    if (input.value === "" && event.keyCode === 32) {
                        event.preventDefault()
                    }
                })

                input.addEventListener("keyup", (event) => {
                    this._hasContent = (this._hasValues || input.value) ? true : false

                    if (this.autocomplete && this._hasContent) {
                        if (input.value !== "" && event.keyCode !== 27) {
                            this._filter()
                        }
                    }
                    if (!this._hasContent) {
                        this._hideTips()
                    }
                })

                this.addEventListener("focusout", this._boundOnFocusout)

                // Difference between the user enter keys and the reserved ones
                const rsrv = new Set(["backspace", "delete", "escape"])
                const diff = new Set(this.enterKeys.filter(val => !rsrv.has(val.toLowerCase())))

                // Imperatively insert keys to the key bindings property
                diff.forEach((key) => this.addOwnKeyBinding(key, "_add"))


                new Polymer.FlattenedNodesObserver(this, this._grabChips)
            }

            disconnectedCallback() {
                super.disconnectedCallback()

                const input = this.inputElement

                input.removeEventListener("iron-input-ready", this._boundOnIronInputReady)

                this.removeEventListener("focusout", this._boundOnFocusout)
            }

            _onValuesChanged(values) {
                if (!values) {
                    this._hasValues = this._hasContent = false
                    return
                }
                this._ensurePlaceholder()
                const uniqueValues = [...new Set(values)]
                if (values.length !== uniqueValues.length) {
                    this.values = uniqueValues
                }
                this._hasValues = this._hasContent = this.values.length > 0
            }

            _ensureValues() {
                if (!this.values) {
                    this.values = []
                }
            }

            _ensurePlaceholder() {
                if (this.values.length > 0) {
                    this._removePlaceholder()
                } else {
                    this._addPlaceholder()
                }
            }

            _popChip() {
                if (this.autocomplete) {
                    this._hideTips()
                    this.pop("values")
                    this._prefilterSource()
                } else {
                    this._ensureValues()
                    this.pop("values")
                    this._ensurePlaceholder()
                }
            }

            _pushChip() {
                const input = this.inputElement
                if (input.value) {
                    this._pushChipByValue(input.value)
                    input.bindValue = ""
                }
            }

            _pushChipByValue(value) {
                value = value.trim()
                this._ensureValues()
                if (this.values.indexOf(value) < 0 && value !== "") {
                    this.push("values", value)
                    this._ensurePlaceholder()
                    this.dispatchEvent(new CustomEvent("chip-added"))
                }
            }

            _removePlaceholder() {
                this.inputElement.removeAttribute("placeholder")
            }

            _addPlaceholder() {
                if (this.placeholder) this.inputElement.setAttribute("placeholder", this.placeholder)
            }

            _filter() {
                const input = this.inputElement
                if (input.value) {
                    this._prefilterSource()
                    this._source = this.filter(this._source, input.value)
                    if (!this._source.length) {
                        this._hideTips()
                    } else {
                        this.hidden = false
                    }
                }
            }

            _select(event) {
                const input = this.inputElement
                this.push("values", event.target.value)
                input.bindValue = ""
                this._hideTips()

                this.$.input.focus()
                this.dispatchEvent(new CustomEvent("chip-added"))
            }

            _removeChip(evt) {
                // Prevent the paper-chip detaches itself from dom-repeat
                evt.preventDefault()

                this._ensureValues()

                // Possible since no chips with the same content are admitted
                const index = this.values.indexOf(evt.model.value)
                const value = evt.model.value

                if (this.autocomplete) {
                    this._hideTips()
                    if (index in this.values) {
                        this.splice("values", index, 1)
                        this._prefilterSource()
                    }
                } else {
                    if (index in this.values) {
                        this.splice("values", index, 1)
                        this._ensurePlaceholder()
                    }
                }
                this.dispatchEvent(new CustomEvent("chip-removed", { detail: { index: index, value: value } }))
            }

            _filterSource(selectedValue) {
                console.log(selectedValue)
                const index = this._source.findIndex((item) => {
                    return this._computeValue(item) === selectedValue
                })

                if (index !== -1) {
                    this.splice("_source", index, 1)
                }
            }

            _prefilterSource() {
                this._source = this.datasource.slice()

                this.values.forEach((item) => {
                    this._filterSource(item)
                })
            }

            _includes(value) {
                return this._source.filter((item) => {
                    return this._computeLabel(item).toLowerCase().includes(value.toLowerCase())
                })
            }

            _startsWith(value) {
                return this._source.filter((item) => {
                    return this._computeLabel(item).toLowerCase().startsWith(value.toLowerCase())
                })
            }
            
            _lookupItem(value) {
                return this.datasource.find((item) => {
                    return this._computeValue(item) === value
                })
            }

            _computeValue(item) {
                return item[this.valueProperty] !== undefined ? item[this.valueProperty] : item
            }

            _computeLabel(item) {
                return item[this.displayProperty] ? item[this.displayProperty] : item
            }

            _lookupLabel(value) {
                const item = this._lookupItem(value)

                if (item !== undefined) {
                    return this._computeLabel(item)
                }

                return value
            }

            _computeIcon(item) {
                return item[this.iconProperty] ? item[this.iconProperty] : ""
            }

            _computeIconSrc(item) {
                return item[this.iconSrcProperty] ? item[this.iconSrcProperty] : ""
            }

            _lookupIcon(value) {
                const item = this._lookupItem(value)

                if (item !== undefined) {
                    return this._computeIcon(item)
                }

                return ""
            }

            _lookupIconSrc(value) {
                const item = this._lookupItem(value)

                if (item !== undefined) {
                    return this._computeIconSrc(item)
                }

                return ""
            }

            _hasIcon(item) {
                return Boolean(this._computeIcon(item) || this._computeIconSrc(item))
            }

            _lookupHasIcon(value) {
                const item = this._lookupItem(value)

                if (item !== undefined) {
                    return this._hasIcon(item)
                }

                return false
            }
                
            _hideTips() {
                if (this.autocomplete) {
                    this.shadowRoot.querySelector("#tips") ? this.shadowRoot.querySelector("#tips").scrollTop = 0 : ""
                    this.hidden = true
                }
            }

            /**
             * Returns a reference to the focusable element. Overridden from PaperInputBehavior
             * to correctly focus the native input.
             */
            get _focusableElement() {
                return this.inputElement.inputElement
            }

        }

        customElements.define(PaperChipInput.is, PaperChipInput)
    </script>
</dom-module>