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jsonpolymerlaravel-5.1service-workerpolymer-starter-kit

Skipping precaching: Cannot read property 'concat' of null`

Here's my question: How might I try to get rid of the 'skipping precaching' and cache everything that comes in from https://laoadventist.info/beta/r as the precache list?

Also, is it correct for me to set precache="https://laoadventist.info/beta/r" or should I be setting that to a function that grabs the data and returns it instead?

Skipping precaching: Cannot read property 'concat' of null comes out on the console when using My Polymer App

<platinum-sw-cache default-cache-strategy="fastest" cache-config-file="cache-config.json" precache="https://laoadventist.info/beta/r">

I am assuming correctly I can precahce a URL like this, right?

I am trying to load a json result from laravel 5.1 to set what my precache should be... I know it's not the most elegant, but I'm new to Polymer, cache, service workers, etc, and using this app as a learning opportunity. It'll be a bit different at the end of the day, but for now I just want to load everything. :)

I want to precache all of the data so that a user can fully utilize this app when offline (though later I'll set it up so that they don't have to precache loads and loads of json requests, only the ones they want, like per book - but that's for later).

Solution

  • If you have a array of resource URLs that you want precached, the cleanest way to specify them is to use the cacheConfigFile option and to point to a JSON file that contains your array as its precache property. Take a look at the example in the docs for cacheConfigFile: https://elements.polymer-project.org/elements/platinum-sw?active=platinum-sw-cache

    You shouldn't have to use the precache attribute on the element if you're using cacheConfigFile.

    It sounds like you're using Polymer Starter Kit, and that will create the JSON config file and populate it for you with an array corresponding to your local resources. But if you'd like to specify additional resources to be precached, you can modify the build process to append those URLs to the auto-generated list.

    The reason you're seeing that error is because you're pointing to a JSON config file that is effectively empty, and is just meant for the development environment.