问题
In Polymer 1.0, I am trying to data bind a string variable {{str}} to an <iron-meta> element (tag in parent element) as follows.
This fails:
<iron-meta id="meta" key="info" value="{{str}}"></iron-meta>
The above code breaks. But the following code works (without the binding).
This works:
<iron-meta id="meta" key="info" value="foo/bar"></iron-meta>
The difference is the variable version {{str}} fails and the constant version "foo/bar" works.
Does anyone have a clue what is what is breaking the binding and how to fix it?
Edits in response to comment questions:
How does it fail? This fails silently. The values I have printed out simply do not update when I press the Login and Register buttons.
Here is a link to the code in a Github repository. See lines
回答1:
You need to use an attribute binding and not a property binding
<input type="text" value$="{{str}}" />
来源：https://stackoverflow.com/questions/31282947/polymer-1-0-data-binding-variable-to-iron-meta-element-value-attribute