Linter complains paper-listbox attr-for-selected name when placed on paper-item

[dman777]

When using paper-listbox and attr-for-selected="value" with paper-item, the linter complains below. Is this a error on the linter part? Everything looks legit Polymer wise. It doesn't matter what name I use for the attr-for-selected, it will complain.

                value="[[picklistValues.ENHANCEDYESNO_DATANOTCOLLECTED]]">
                ~~~~~

src/sp-elements/sp-static-forms/sp-disabilities/sp-disabilities-form-edit.html(404,17) warning [set-unknown-attribute] - paper-item elements do not have a property named value. Consider instead:  role$

---

                <paper-listbox
                  attr-for-selected="value"
                  selected="yes"
                  class="dropdown-content">
                  <paper-item
                    value="[[picklistValues.ENHANCEDYESNO_YES]]">
                    Yes
                  </paper-item>

[morbidick]

you have to set it as an attribute:

                  <paper-item
                    value$="[[picklistValues.ENHANCEDYESNO_YES]]">
                    Yes
                  </paper-item>

By default Polymer data binding sets property values.

[dman777]

Thanks.

Could the verbiage need refinement? the value is a attribute. From documentation, $ is used for html native attributes or dynamic values. But the without the $, value is still a attribute.

[jsilvermist]

paper-listbox is getting the selected attribute using:

var propValue = item[dashToCamelCase(this.attrForSelected)];
return propValue != undefined ? propValue :
                                item.getAttribute(this.attrForSelected);

So it's getting the property first, and if it's not set it falls back to the attribute.

In this case, value isn't defined on paper-item as a property, so binding to it's attribute instead is a good way to avoid any issues with the linter, as I don't believe it should cause a linter error.

value="[[foo]]" will generate: el.value = this.foo;
value$="[[foo]]" will generate: el.setAttribute('value', this.foo) (More or less, slightly different in the case of boolean attributes)