Add support for archiving assignments.

Downloads the assignment attachments and the latest submission to the assignment.

Fix a bug where if you reselected two sets of courses and downloaded one after the other in the same session, the second download would download the files for the UNION of both selections.

src/MoodleAPI.js

@@ -95,10 +95,49 @@ export class MoodleClient {
         return courses;
     }
 
+    async getAssignmentDetailsAndSubmissionFiles(instanceid) {
+        if (this.token === null) {
+            throw new Error("token not recieved yet");
+        }
+        let bodyContent = new MoodleFormData();
+        let details = [];
+        bodyContent.append("wstoken", this.token);
+        bodyContent.append("wsfunction", "mod_assign_get_submission_status");
+        bodyContent.append("assignid", instanceid);
+        let response = await fetch(`${this.backend}/webservice/rest/server.php`, {
+            method: "POST",
+            body: bodyContent,
+            headers: this.headersList
+        });
+        let data = await response.json();
+        if ("errorcode" in data) {
+            throw new Error(data["errorcode"])
+        }
+
+        let submission = data["lastattempt"]["submission"];
+        for (let plugin of submission["plugins"]) {
+            if (plugin["type"] === "file") {
+                for (let filearea of plugin["fileareas"]) {
+                    if (filearea["area"] === "submission_files") {
+                        details.push(...filearea["files"])
+                    }
+                }
+            }
+        }
+
+        let assignmentdata = data["assignmentdata"];
+        if ("attachments" in assignmentdata) {
+            if ("intro" in assignmentdata["attachments"]) {
+                details.push(...assignmentdata["attachments"]["intro"]);
+            }
+        }
+        return details;
+    }
     async getFilesForDownload(courses) {
         if (this.token === null) {
             throw new Error("token not recieved yet");
         }
+        this.files = {};
         for (let course of courses) {
             this.files[course["shortname"]] = {};
 
@@ -121,7 +160,6 @@ export class MoodleClient {
                 this.files[course["shortname"]][sectionname] = []
                 for (let module of section["modules"]) {
                     if ("modplural" in module) {
-                        // TODO: Add support for downloading assignments too.
                         if (["Files", "Folders"].includes(module["modplural"])) {
                             for (let content of module["contents"]) {
                                 if (content["type"] === "file") {
@@ -135,12 +173,23 @@ export class MoodleClient {
                                             // of the folder. By default the filepath is '/', so when we prepend,
                                             // the path becomes 'foldername/' and the file is saved at
                                             // "foldername/filename.filextension" instead of at "/filename.filextension"
-                                            "filepath": module["modplural"] === "Folders" ? module["name"] + content["filepath"] : content["filepath"],
+                                            "filepath": module["modplural"] === "Folders" ? this.makeStringPathSafe(module["name"]) + content["filepath"] : content["filepath"],
                                         }
                                     )
                                 }
                             }
                         }
+                        else if (module["modplural"] === "Assignments") {
+                            let detailsandubmissionfiles = await this.getAssignmentDetailsAndSubmissionFiles(module["instance"])
+                            for (let dOrSubfile of detailsandubmissionfiles) {
+                                this.files[course["shortname"]][sectionname].push({
+                                    "fileurl": dOrSubfile["fileurl"],
+                                    "filename": dOrSubfile["filename"],
+                                    "filepath": this.makeStringPathSafe(module["name"]) + dOrSubfile["filepath"]
+                                })
+                            }
+
+                        }
                     }
                 }
             }
@@ -158,7 +207,11 @@ export class MoodleClient {
             for (let section in sections) {
                 var sectionfolder = coursefolder.folder(section);
                 for (let module of sections[section]) {
-                    // a module is either a file or folder. see TODO in func above.
+                    // This module (in this scope alone) is slightly different
+                    // from a moodle module which is either a file or folder
+                    // here, it is a file, or folder that has been uploaded
+                    // as a module itself, or it might also be attachments to
+                    // a particular assignment.
                     let bodyContent = new MoodleFormData();
                     bodyContent.append("token", this.token);
                     let response = await fetch(module["fileurl"], {