How to use the @lrnwebcomponents/haxcms-elements/lib/core/haxcms-site-store.js.store.activeTitle function in @lrnwebcomponents/haxcms-elements

autorun(reaction => {
      this.activeTitle = toJS(store.activeTitle);
      this.shareUrl = document.location.href;
      this.shareMsg = this.activeTitle + " " + this.shareUrl;
      if (varGet(store.activeItem, "metadata.fields.subtitle", false)) {
        this.subtitle = store.activeItem.metadata.fields.subtitle;
      } else {
        this.subtitle = false;
      }
      // look for image on the post and make it the pin share
      if (varGet(store.activeItem, "metadata.fields.images.0.src", false)) {
        this.activeImage = store.activeItem.metadata.fields.images[0].src;
      }
      this.__disposer.push(reaction);
    });
  }

autorun(reaction => {
      this.activeTitle = toJS(store.activeTitle);
      this.shareUrl = document.location.href;
      this.shareMsg = this.activeTitle + " " + this.shareUrl;
      if (varGet(store.activeItem, "metadata.fields.subtitle", false)) {
        this.subtitle = store.activeItem.metadata.fields.subtitle;
      } else {
        this.subtitle = false;
      }
      // look for image on the post and make it the pin share
      if (varGet(store.activeItem, "metadata.fields.images.0.src", false)) {
        this.activeImage = store.activeItem.metadata.fields.images[0].src;
      }
      this.__disposer.push(reaction);
    });
  }

autorun(reaction => {
      this.activeTitle = toJS(store.activeTitle);
      this.shareUrl = document.location.href;
      this.shareMsg = this.activeTitle + " " + this.shareUrl;
      if (varGet(store.activeItem, "metadata.fields.subtitle", false)) {
        this.subtitle = store.activeItem.metadata.fields.subtitle;
      } else {
        this.subtitle = false;
      }
      // look for image on the post and make it the pin share
      if (varGet(store.activeItem, "metadata.fields.images.0.src", false)) {
        this.activeImage = store.activeItem.metadata.fields.images[0].src;
      }
      this.__disposer.push(reaction);
    });
  }

b2.appendChild(document.createTextNode("cancel"));
    b2.setAttribute("dialog-dismiss", "dialog-dismiss");
    let b = document.createElement("div");
    b.style.position = "absolute";
    b.style.bottom = 0;
    b.style.left = 0;
    b.style.right = 0;
    b.style.zIndex = 1000000;
    b.appendChild(b1);
    b.appendChild(b2);
    const evt = new CustomEvent("simple-modal-show", {
      bubbles: true,
      composed: true,
      cancelable: false,
      detail: {
        title: "Edit " + store.activeTitle + " fields",
        styles: {
          "--simple-modal-width": "75vw",
          "--simple-modal-max-width": "75vw"
        },
        elements: {
          content: c,
          buttons: b
        },
        invokedBy: this.__nodeFieldsInvoked,
        clone: false,
        modal: true
      }
    });
    window.dispatchEvent(evt);
  }

autorun(reaction => {
      this.activeTitle = toJS(store.activeTitle);
      this.__title = this._makeTitle(
        this.dynamicMethodology,
        this.activeTitle,
        this.parentTitle,
        this.ancestorTitle
      );
      this.__disposer.push(reaction);
    });
    autorun(reaction => {