paginate followers

src/apps/web/TODO

@@ -1,5 +1,4 @@
 read
-  ! paginate followers
   * nostr: links not replaced in feed titles
   * support nprofile/nevent/etc links
   * non-500 error pages when bech32 fails to parse, for example

src/apps/web/WebData.h

@@ -128,13 +128,15 @@ struct User {
         kind3Event = loadKindEvent(txn, decomp, 3);
     }
 
-    std::vector<std::string> getFollowers(lmdb::txn &txn, Decompressor &decomp, const std::string &pubkey) {
+    std::vector<std::string> getFollowers(lmdb::txn &txn, Decompressor &decomp, const std::string &pubkey, uint64_t offset = 0, uint64_t limit = MAX_U64, uint64_t *countOut = nullptr) {
         std::vector<std::string> output;
         flat_hash_set<std::string> alreadySeen;
 
         std::string prefix = "p";
         prefix += pubkey;
 
+        uint64_t curr = 0;
+
         env.generic_foreachFull(txn, env.dbi_Event__tag, prefix, "", [&](std::string_view k, std::string_view v){
             ParsedKey_StringUint64 parsedKey(k);
             if (parsedKey.s != prefix) return false;
@@ -148,13 +150,15 @@ struct User {
 
                 if (!alreadySeen.contains(pubkey)) {
                     alreadySeen.insert(pubkey);
-                    output.emplace_back(std::move(pubkey));
+                    curr++;
+                    if (curr >= offset && curr - offset < limit) output.emplace_back(std::move(pubkey));
                 }
             }
 
             return true;
         });
 
+        if (countOut) *countOut = curr;
         return output;
     }
 };

src/apps/web/WebReader.cpp

@@ -186,8 +186,11 @@ HTTPResponse WebServer::generateReadResponse(lmdb::txn &txn, Decompressor &decom
     auto handleFeed = [&](std::string_view feedId){
         uint64_t resultsPerPage = 30;
         uint64_t page = 0;
-        auto pageStr = u.lookupQuery("p");
-        if (pageStr) page = std::stoull(std::string(*pageStr));
+
+        try {
+            auto pageStr = u.lookupQuery("p");
+            if (pageStr) page = std::stoull(std::string(*pageStr));
+        } catch(...) {}
 
         feedReader.emplace(txn, decomp, feedId);
 
@@ -267,28 +270,54 @@ HTTPResponse WebServer::generateReadResponse(lmdb::txn &txn, Decompressor &decom
                 title = std::string("following: ") + user.username;
                 user.populateContactList(txn, decomp);
 
+                uint64_t numFollowing = 0;
+                if (user.kind3Event) {
+                    for (const auto &tagJson : user.kind3Event->at("tags").get_array()) {
+                        const auto &tag = tagJson.get_array();
+                        if (tag.size() >= 2 && tag.at(0).get_string() == "p") numFollowing++;
+                    }
+                }
+
                 struct {
                     User &user;
                     std::function<const User*(const std::string &)> getUser;
+                    uint64_t numFollowing;
                 } ctx = {
                     user,
                     [&](const std::string &pubkey){ return userCache.getUser(txn, decomp, pubkey); },
+                    numFollowing,
                 };
 
                 body = tmpl::user::following(ctx);
             } else if (u.path[2] == "followers") {
+                uint64_t resultsPerPage = 500;
+                uint64_t page = 0;
+
+                try {
+                    auto pageStr = u.lookupQuery("p");
+                    if (pageStr) page = std::stoull(std::string(*pageStr));
+                } catch(...) {}
+
                 User user(txn, decomp, userPubkey);
                 title = std::string("followers: ") + user.username;
-                auto followers = user.getFollowers(txn, decomp, user.pubkey);
+                uint64_t numFollowers = 0;
+                auto followers = user.getFollowers(txn, decomp, user.pubkey, page * resultsPerPage, resultsPerPage, &numFollowers);
+                uint64_t numPages = (numFollowers + resultsPerPage + 1) / resultsPerPage;
 
                 struct {
                     const User &user;
                     const std::vector<std::string> &followers;
+                    uint64_t numFollowers;
                     std::function<const User*(const std::string &)> getUser;
+                    uint64_t page;
+                    uint64_t numPages;
                 } ctx = {
                     user,
                     followers,
+                    numFollowers,
                     [&](const std::string &pubkey){ return userCache.getUser(txn, decomp, pubkey); },
+                    page,
+                    numPages,
                 };
 
                 body = tmpl::user::followers(ctx);

src/apps/web/static/oddbean.css

@@ -292,6 +292,14 @@ table.vert {
     margin-left: 40px;
 }
 
+.pagination-links {
+    margin-top: 40px;
+    text-align: center;
+    > * {
+        margin: 10px;
+    }
+}
+
 .feed-info {
     .feed-id {
         background-color: #dfdfdf;

src/apps/web/tmpls/feed/list.tmpl

@@ -3,6 +3,6 @@
 </div>
 
 <div class="feed-nav-links">
-    <a href="./?p=$(ctx.page + 1)">More</a> ?(ctx.n != 0)
+    <a href="?p=$(ctx.page + 1)">More</a> ?(ctx.n != 0)
     <span>The end.</span> ?(ctx.n == 0)
 </div>

src/apps/web/tmpls/user/followers.tmpl

@@ -1,4 +1,6 @@
 <div class="user-followers">
+    <h2><a href="/u/$(ctx.user.npubId)">$(ctx.user.username)</a> has $(ctx.numFollowers) known followers.</h2>
+
     <table class="vert">
         <tr>
             <th>user</th>
@@ -16,4 +18,10 @@
         </>
 
     </table>
+
+    <div class="pagination-links">
+        <a href="?p=$(ctx.page - 1)">Prev</a> ?(ctx.numPages && ctx.page > 0)
+        <span>$(ctx.page + 1) / $(ctx.numPages)</span>
+        <a href="?p=$(ctx.page + 1)">Next</a> ?(ctx.numPages && ctx.page < ctx.numPages-1)
+    </div>
 </div>

src/apps/web/tmpls/user/following.tmpl

@@ -1,4 +1,6 @@
 <div class="user-following">
+    <h2><a href="/u/$(ctx.user.npubId)">$(ctx.user.username)</a> is following $(ctx.numFollowing) users.</h2> ?(ctx.user.kind3Event)
+
     <div> ?(!ctx.user.kind3Event)
         No kind 3 contact list found for $(ctx.user.npubId)
     </div>