book: add filters JavaScript examples

- Updated index.js
- Added filters.js with example code
- Updated 05_01_01-filter.md to include examples in book

book/snippets/nostr/js/index.js

@@ -1,6 +1,7 @@
 const keys = require("./src/keys");
 const eventJson = require("./src/event/json");
 const eventBuilder = require("./src/event/builder");
+const filters = require("./src/messages/filters");
 const relayMessages = require("./src/messages/relay");
 const nip01 = require("./src/nip01");
 const nip05 = require("./src/nip05");
@@ -21,6 +22,7 @@ async function main() {
     eventBuilder.eventBuilder();
 
     await relayMessages.run();
+    await filters.run();
 
     nip01.run();
     await nip05.run();

book/snippets/nostr/js/src/messages/filters.js

@@ -0,0 +1,157 @@
+const { Filter, Keys, Kind, EventBuilder, Timestamp, Tag, loadWasmSync } = require('@rust-nostr/nostr');
+
+async function run() {
+    loadWasmSync();
+
+    // Generate keys and Events
+    const keys = Keys.generate();
+    const keys2 = Keys.generate();
+
+    const kind0 = new Kind(0); 
+    const kind1 = new Kind(1);
+    const kind4 = new Kind(4);
+
+    const event = EventBuilder.textNote("Hello World!", []).toEvent(keys);
+    const event2 = new EventBuilder(kind0, "Goodbye World!", [Tag.identifier("Identification D Tag")]).toEvent(keys2);
+
+    console.log();
+    console.log("Creating Filters:");
+
+    // ANCHOR: create-filter-id
+    // Filter for specific ID
+    console.log("  Filter for specific Event ID:");
+    let f = new Filter().id(event.id);
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-id
+
+    console.log();
+    // ANCHOR: create-filter-author
+    // Filter for specific Author
+    console.log("  Filter for specific Author:");
+    f = new Filter().author(keys.publicKey);
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-author
+
+    console.log();
+    // ANCHOR: create-filter-kind-pk
+    // Filter by PK and Kinds
+    console.log("  Filter with PK and Kinds:");
+    f = new Filter()
+        .pubkey(keys.publicKey)
+        .kind(kind1);
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-kind-pk
+
+    console.log();
+    // ANCHOR: create-filter-search
+    // Filter for specific string
+    console.log("  Filter for specific search string:");
+    f = new Filter().search("Ask Nostr Anything");
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-search
+
+    console.log();
+    // ANCHOR: create-filter-timeframe
+    console.log("  Filter for events from specific public key within given timeframe:");
+    // Create timestamps
+    const date = new Date(2009, 1, 3, 0, 0);
+    const timestamp = Math.floor(date.getTime() / 1000);
+    const sinceTs = Timestamp.fromSecs(timestamp);
+    const untilTs = Timestamp.now();
+
+    // Filter with timeframe
+    f = new Filter()
+        .pubkey(keys.publicKey)
+        .since(sinceTs)
+        .until(untilTs);
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-timeframe
+
+    console.log();
+    // ANCHOR: create-filter-limit
+    // Filter for specific PK with limit
+    console.log("  Filter for specific Author, limited to 10 Events:");
+    f = new Filter()
+        .author(keys.publicKey)
+        .limit(10);
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-limit
+
+    console.log();
+    // ANCHOR: create-filter-hashtag
+    // Filter for Hashtags
+    console.log("  Filter for a list of Hashtags:");
+    f = new Filter().hashtags(["#Bitcoin", "#AskNostr", "#Meme"]);
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-hashtag
+
+    console.log();
+    // ANCHOR: create-filter-reference
+    // Filter for Reference
+    console.log("  Filter for a Reference:");
+    f = new Filter().reference("This is my NIP-12 Reference");
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-reference
+
+    console.log();
+    // ANCHOR: create-filter-identifier
+    // Filter for Identifier
+    console.log("  Filter for a Identifier:");
+    f = new Filter().identifier("This is my NIP-12 Identifier");
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: create-filter-identifier
+
+    console.log();
+    console.log("Modifying Filters:");
+    // ANCHOR: modify-filter
+    // Modifying Filters (adding/removing)
+    f = new Filter()
+        .pubkeys([keys.publicKey, keys2.publicKey])
+        .ids([event.id, event2.id])
+        .kinds([kind0, kind1])
+        .author(keys.publicKey);
+
+    // Add an additional Kind to existing filter
+    f = f.kinds([kind4]);
+
+    // Print Results
+    console.log("  Before:");
+    console.log(`     ${f.asJson()}`);
+    console.log();
+
+    // Remove PKs, Kinds and IDs from filter
+    f = f.removePubkeys([keys2.publicKey]);
+    console.log(" After (remove pubkeys):");
+    console.log(`     ${f.asJson()}`);
+    kind_rem0 = new Kind(0);
+    kind_rem4 = new Kind(4);
+    f = f.removeKinds([kind_rem0, kind_rem4]);
+    console.log("  After (remove kinds):");
+    console.log(`     ${f.asJson()}`);
+
+    f = f.removeIds([event2.id]);
+    console.log("  After (remove IDs):");
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: modify-filter
+
+    console.log();
+    console.log("Other Filter Operations:");
+    // ANCHOR: other-parse
+    // Parse filter
+    console.log("  Parse Filter from Json:");
+    const fJson = f.asJson();
+    f = Filter.fromJson(fJson);
+    console.log(`     ${f.asJson()}`);
+    // ANCHOR_END: other-parse
+
+    console.log();
+    // ANCHOR: other-match
+    console.log("  Logical tests:");
+    kind_match = new Kind(1);
+    f = new Filter().author(keys.publicKey).kind(kind_match);
+    console.log(`     Event match for filter: ${f.matchEvent(event)}`);
+    console.log(`     Event2 match for filter: ${f.matchEvent(event2)}`);
+    // ANCHOR_END: other-match
+}
+
+module.exports.run = run;

book/src/nostr/05_01_01-filter.md

@@ -37,7 +37,7 @@ Filtering events by author using `author()`.
 {{#include ../../snippets/nostr/python/src/messages/filters.py:create-filter-author}}
 ```
 
-Filtering events based on multiple criteria. In this case, by public key using `public_key()` and kind using `kind()`.
+Filtering events based on multiple criteria. In this case, by public key using `pubkey()` and kind using `kind()`.
 
 ```python,ignore
 {{#include ../../snippets/nostr/python/src/messages/filters.py:create-filter-kind-pk}}
@@ -78,7 +78,55 @@ Finally, filtering using hashtags (`hashtag()`), NIP-12 reference tags (`referen
 <div slot="title">JavaScript</div>
 <section>
 
-TODO
+The following code examples all utilise the `Filters()` along with associated methods to create filter objects and print these in JSON format using the `asJson()` method.
+
+Filtering events based on a specific event ID using `id()`.
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-id}}
+```
+
+Filtering events by author using `author()`.
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-author}}
+```
+
+Filtering events based on multiple criteria. In this case, by public key using `pubkey()` and kind using `kind()`.
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-kind-pk}}
+```
+
+Filtering for specific text strings using `search()`.
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-search}}
+```
+
+Restricting query results to specific timeframes (using `since()` and `until()`), as well as limiting search results to a maximum of 10 records using `limit()`.
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-timeframe}}
+```
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-limit}}
+```
+
+Finally, filtering using hashtags (`hashtags()`), NIP-12 reference tags (`reference()`) and identifiers (`identifiers()`), respectively.
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-hashtag}}
+```
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-reference}}
+```
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:create-filter-identifier}}
+```
 
 </section>
 
@@ -125,8 +173,14 @@ Similarly, the range of 'remove' methods (e.g. `remove_kinds()`) allow us to tak
 <div slot="title">JavaScript</div>
 <section>
 
-TODO
+Adding more conditions to existing objects can be done by simply calling the relevant method on the instance of the object. 
+In this example we create a initial filter with `pubkeys()`, `ids()`, `kinds()` and a single `author()` then modify the object further to include another kind (4) to the existing list of kinds (0, 1).
+
+Similarly, the range of 'remove' methods (e.g. `removekinds()`) allow us to take an existing filter and remove unwanted conditions without needed to reconstruct the filter object from scratch.
 
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:modify-filter}}
+```
 </section>
 
 <div slot="title">Kotlin</div>
@@ -181,7 +235,17 @@ To perform a logical test and determine if a given event object matches existing
 <div slot="title">JavaScript</div>
 <section>
 
-TODO
+We can parse existing filter JSON object using the `fromJson()` method when instantiating a filter object.
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:other-parse}}
+```
+
+To perform a logical test and determine if a given event object matches existing filter conditions the `matchEvent()` method can be used. 
+
+```javascript,ignore
+{{#include ../../snippets/nostr/js/src/messages/filters.js:other-match}}
+```
 
 </section>