strolch-wc-localize-behavior/strolch-wc-localize-behavior.html

<link rel="import" href="../app-localize-behavior/app-localize-behavior.html">

<script>

    // custom behaviour accessing the configuration above
    StrolchLocalizeBehaviorImpl = {
        properties: {
            fallbackLanguage: {
                type: String,
                value: "en"
            }
        },
        created: function () {
            this.__computeLocalizeOld = this.__computeLocalize;
            this.__computeLocalize = function (language, resources, formats) {
                var localizeFunc;
                if (!resources[language])
                    localizeFunc = this.__computeLocalizeOld(this.fallbackLanguage, resources, formats).bind(this);
                localizeFunc = this.__computeLocalizeOld(language, resources, formats).bind(this);

                return function () {
                    var key = arguments[0];
                    if(!key)
                        return;
                    if (!resources || !language || !resources[language])
                        return key;

                    try {
                        return localizeFunc.apply(this, arguments);
                    } catch (e) {
                        console.log("Failed to translate key " + key);
                        console.log(e);
                        return key;
                    }
                }.bind(this);
            }.bind(this);
        },
        attached: function () {
            // load the language resource of the configured language
            this.language = Strolch.getUserLocale();
            this.useKeyIfMissing = true;

            if (Strolch.isNotEmptyString(this.localesPath)) {
                this.loadResources(this.resolveUrl(this.localesPath));
            }
        },
    };

    // inherit the behavior of the standard polymer localization
    StrolchLocalizeBehavior = [Polymer.AppLocalizeBehavior, StrolchLocalizeBehaviorImpl];
</script>