Polymer - Change paper-toolbar contents depending on selected iron-page

Question

Expanding on the Polymer Starter Kit I'm struggling to figure out how I can change the hamburger(menu) icon to a different button when a different iron-page is active.

---

index.html

<paper-toolbar class="paper-toolbar-0" id="mainToolbar">

  <paper-icon-button id="paperToggle" icon="menu" paper-drawer-toggle></paper-icon-button>
  <!-- more toolbar content here -->

</paper-toolbar>

<iron-pages attr-for-selected="data-route" class="layout vertical center" selected="{{route}}">

  <!-- Top Stories -->     
  <section data-route="topstories">
    <story-list id="story-list" class="layout vertical center-justified"></story-list>
  </section>

   <!-- Item Info -->     
  <section data-route="item-info" class="fullbleed layout center-justified">
    <item-info firebase-item-id="[[params.firebaseitemid]]" class="fullbleed flex"></item-info>
  </section>

</iron-pages>

---

When the item-info route is selected, I would like to replace the menu paper-toggle-button with a back button. Possibly changing the toolbar text from the application title to 'Back to Top Stories' say.

Now, I think this is possible by setting an id on each of these controls and then have some Javascript in the item-info element that makes these changes. I'd prefer something a little more modular as this would tie my item-info element very closely to content that is external to it.

Answer 1

I did a custom polymer element to which you pass an array of icons and puts them on the toolbar.

Here is the code:

<dom-module id="my-toolbar-icons">
<template>
    <template is="dom-repeat" items="{{contextualButtons}}" as="button" id="buttonsRepeat">
        <paper-icon-button contextual-action="{{button.action}}" icon="{{button.icon}}" on-tap="onContextualButtonTap"></paper-icon-button>
    </template>
</template>

<script>
Polymer({
    is: 'my-toolbar-icons',
    properties: {
        contextualButtons: {
            type: Array,
            value: function () {
                return [];
            }
        }
    },
    ready: function(){
        //set data just to show an icon
        this.contextualButtons = [{ icon: 'social:person-add', action: 'new' }, { icon: 'delete', action: 'delete' }, { icon: 'cloud-upload', action: 'update' }, { icon: 'image:camera-alt', action: 'takephoto' }, { icon: 'search', action: 'search' }];
    },
    setData: function (newContextualButtons) {
        //set data to the array (usage)
        //var item = document.querySelector("#id-of-this-element")
        //item.setData(someArrayOfIcons)
        this.contextualButtons = newContextualButtons;
    },
    onContextualButtonTap: function (event) {
        var item = this.$.buttonsRepeat.itemForElement(event.target);
        this.fire('customize-listener', item.action);
    }
});
</script>
</dom-module>

<!--Usage-->
<my-toolbar-icons id="my-toolbar-icons"></my-toolbar-icons> <!--declaration-->

<!--with javascript-->
this.toolbar= document.querySelector("#my-toolbar-icons");
this.toolbar.setData([{ icon: 'social:person-add', action: 'new' }]);

This is just an idea that can be used to make you want to do.