Get and set other field values from within a field plugin

The CMS Questions
1

I like to build a field plugin where I read the value of an existing field “ISBN” make an isbn api call and populate the fields “title”, “publisher”, “author” ect.
I do not know how to access the data outside of the plugin.
AI suggestet using this.$store, but it is undefined inside the plugin

here is my basic script:

panel.plugin("me/isbnfetcher", {
  fields: {
    isbnfetcher: {
      props: {
        label: String
      },
      methods: {
        updateField(field, value) {
          this.$root.$store.dispatch("content/update", {
            field: field,
            value: value
          });
        },
        fetchMeta() {
          console.log("this.$store:", this.$store);
          const isbn = this.$store.getters["content/values"].isbn;
        }
      },
      template: `
        <k-field :label="label">
          <k-button @click="fetchMeta">Metadaten laden</k-button>
        </k-field>
      `
    }
  }
});
2

AI is still on v4 with that recommendation. This part changed with Kirby 5. You can now do this via the this.$panel.content module. You can find some info on it here: https://lab.getkirby.com/public/lab/internals/panel/content

For your case, check out the “Update changes” example at the button