如何获得 <iron-icons> 在Polymer 2.x中工作

Question

Narrow Question

By troubleshooting, I think I have narrowed my "larger problem" down to the following question. (But I could be wrong.):

How do I properly download the latest version of <iron-icons> to my local machine?

By "latest version," I mean the version that is imported via the following:

<base href="//polygit.org/polymer+:master/components/">
<link rel="import" href="iron-icons/iron-icons.html">

The above version of importing <iron-icons> works on my demo here.

However, when I do either of the following:

bower install --save PolymerElements/iron-icons

bower update --save

And try to import on my local server like this:

<link rel="import" href="/bower_components/iron-icons/iron-icons.html">

it fails silently and I see no icons at all. But I do see extra space where the icons are supposed to render.

Bigger Question (the real problem I'm trying to solve)

I am trying to get my <iron-icons> to render properly in the browser.

What I expect to see

I expect to see a two <iron-icon> elements like this:

(anchored in between other test elements: Hello World and <img> )

What I actually see

No icons at all. But white space where they should render.

Steps to reproduce

Run

bower install --save PolymerElements/iron-icons

or, if <iron-icons> is already installed:

bower update --save

then

polyserve

or

polymer serve

Version

I believe I am using v2.0.1 of <iron-icons> . Here is the entire contents of the bower.json file.

bower.json

 "iron-icons": "PolymerElements/iron-icons#^2.0.1", 

Configuration

OS: macOS Sierra 10.12.6
Hardware: MacBook Air
Browser: Chrome Version 60.0.3112.113 (Official Build) (64-bit)

Demo

Here is my Plunker demo.

Code

The following code does render <iron-icons> as expected:

http://plnkr.co/edit/pKnrlIbGhfQPFq10aAJS?p=preview

 <base href="//polygit.org/polymer+:master/components/"> <script src="webcomponentsjs/webcomponents-lite.js"></script> <link rel="import" href="polymer/polymer-element.html"> <link rel="import" href="iron-icons/iron-icons.html"> <link rel="import" href="iron-icon/iron-icon.html"> <dom-module id="demo-el"> <template> Hello world <iron-icon icon="add"></iron-icon> <iron-icon icon="favorite"></iron-icon> <img src="//lorempixel.com/400/200/" /> </template> <script> class DemoEl extends Polymer.Element { static get is() { return 'demo-el' } constructor() { super(); } } customElements.define(DemoEl.is, DemoEl); </script> </dom-module> 

The following code does NOT render <iron-icons> as expected (served locally):

 <link rel="import" href="/bower_components/polymer/polymer-element.html"> <link rel="import" href="/bower_components/webcomponentsjs/webcomponents-lite.js"> <link rel="import" href="/bower_components/iron-icon/iron-icon.html"> <link rel="import" href="/bower_components/iron-icons/iron-icons.html"> <link rel="import" href="/bower_components/paper-input/paper-input.html"> <dom-module id="app-main"> <template> Hello world <iron-icon icon="add"></iron-icon> <iron-icon icon="favorite"></iron-icon> <img src="//lorempixel.com/400/200/" /> </template> <script> class AppMain extends Polymer.Element { static get is() { return 'app-main' } constructor() { super(); } } customElements.define(AppMain.is, AppMain); </script> </dom-module> 

However, the above code does render <iron-icons> as expected when I do a direct substitution of:

 <base href="//polygit.org/polymer+:master/components/"> <link rel="import" href="iron-icons/iron-icons.html"> 

for

<base href="//polygit.org/polymer+:master/components/">
<link rel="import" href="iron-icons/iron-icons.html">

Edit

By comparing the text of the imported files using the CDN

 <base href="//polygit.org/polymer+:master/components/"> <link rel="import" href="iron-icons/iron-icons.html"> 

and local imports:

 <link rel="import" href="/bower_components/iron-icons/iron-icons.html"> 

I discovered there is a discrepancy in the imported version of the iron-iconset-svg.html file. My bower.json file says the dependent version is "iron-iconset-svg": "1 - 2" or "iron-iconset-svg": "polymerelements/iron-iconset-svg#^2.0.0" but the bower.json file here says the dependent version is "iron-iconset-svg": "polymerelements/iron-iconset-svg#^1.0.0"

So, now the question appears to reduce to how do I get the local version of iron-icons.html to import the same version of iron-iconset-svg.html as the online CDN import version.

Edit 2

The problem persists when I just copy the iron-iconset-svg.html file from the CDN and paste it into my local file system. So, apparently something else is going on too.

Edit 3

I followed the instructions here for upgrading to Polymer 2.0:

https://www.polymer-project.org/2.0/docs/upgrade#update-bower-dependencies

1. Remove the existing bower_components folder.

bower install

2. Update the Polymer version in bower.json to the latest versions.

"dependencies" : {
  ...
  "polymer-elements" : "^2.0.0",
  ...
}

3. Install the new dependencies.

"dependencies" : {
  ...
  "polymerelements" : "^2.0.0",
  ...
}

This did not solve the problem. However I could not update Polymer elements to ^2.0.0

bower.json

 "dependencies" : { ... "polymer-elements" : "^2.0.0", ... } 

caused an error and so did:

bower.json

 "dependencies" : { ... "polymerelements" : "^2.0.0", ... } 

and so did:

bower.json

 "dependencies" : { ... "PolymerElements" : "^2.0.0", ... } 

Answer 1

The solution proposed by @Ofisora in the comments works for me—update iron-selector and iron-meta :

bower install --save PolymerElements/iron-meta
bower install --save PolymerElements/iron-selector

Answer 2

iron-icons is a utility import that includes the definition for the iron-icon element, iron-iconset-svg element, as well as an import for the default icon set.

This means that iron-icons is directly dependent on both iron-icon and iron-iconset-svg . And both iron-icon and iron-iconset-svg element depends on iron-meta .

When you update iron-icons to the latest version, these elements iron-icon , iron-iconset-svg and iron-meta might not get updated since you will get all these components by default. So, updating iron-meta is one of the solution.

---

Also, when you install or update element in polymer you will see messages like:

Unable to find a suitable version for iron-icons, please choose one by typing one of the numbers below:

Always choose the suitable or latest version depending on other element you have.

When finished updating or installing you will see a note like:

 Please note that, iron-iconset-svg#a47e824859 depends on iron-meta#2.0-preview which resolved to iron-meta#7404b31da3 iron-icon#1.0.13, iron-icon#1.0.13, iron-icon#1.0.13, iron-iconset-svg#1.1.2, iron-iconset-svg#1.1.2 depends on iron-meta#^1.0.0 which resolved to iron-meta#1.1.3 iron-icon#2.0.0, iron-iconset-svg#2.0.0 depends on iron-meta#1 - 2 which resolved to iron-meta#2.0.2 

Make sure you read this and install/update dependencies required.

---

Note: In my case I had to update iron-selector as well since I was using iron-icon inside the iron-selector .