feat(appellate): Adds helper function to check document availability

Introduces a new function to determine if a particular document within a multi-doc page is available in the recap archive.

src/appellate/appellate.js

@@ -1048,6 +1048,50 @@ AppellateDelegate.prototype.handleCombinedPdfPageView = async function () {
  document.body.appendChild(warning);
  return;
  }
+
+ await this.checkSingleDocInCombinedPDFPage();
+};
+
+AppellateDelegate.prototype.checkSingleDocInCombinedPDFPage = async function(){
+ let clCourt = PACER.convertToCourtListenerCourt(this.court);
+ // Retrieves a partial document ID from the URL parameter named `"dls"`. It's
+ // important to note that this value might not be the complete document ID.
+ // It could potentially be a shortened version of the full ID.
+ let urlParams = new URLSearchParams(window.location.search);
+ let partialDocId = urlParams.get('dls').split(',')[0];
+
+ // If the `this.pacer_doc_id` property is not already set, attempt to retrieve
+ // it using the previously extracted partial document ID. The returned full
+ // document ID is then stored in the `this.pacer_doc_id` property for
+ // subsequent use.
+ if (!this.docId) {
+ this.docId = await getPacerDocIdFromPartialId(
+ this.tabId,
+ partialDocId
+ );
+ }
+
+ // If we don't have this.pacer_doc_id at this point, punt.
+ if (!this.docId) return;
+
+ const recapLinks = await dispatchBackgroundFetch({
+ action: 'getAvailabilityForDocuments',
+ data: {
+ docket_entry__docket__court: clCourt,
+ pacer_doc_id__in: this.docId,
+ },
+ });
+ if (!recapLinks.results.length) return;
+ console.info(
+ 'RECAP: Got results from API. Processing results to insert link'
+ );
+ let result = recapLinks.results.filter(
+ (doc) => doc.pacer_doc_id === this.docId,
+ this
+ );
+ if (!result.length) return;
+
+ insertAvailableDocBanner(result[0].filepath_local, 'body');
 };
 
 // If this page offers a single document, intercept navigation to the document