From b81137ad254331e8c16468225bb2fcee0b500f1d Mon Sep 17 00:00:00 2001
From: Magnus Hoff <maghoff@gmail.com>
Date: Wed, 25 Oct 2017 16:34:21 +0200
Subject: [PATCH] Prev and next-links for search result. "More"-link for
 instant search

---
 assets/search.js                 | 29 +++++++++++--
 assets/style.css                 |  1 +
 src/resources/search_resource.rs | 70 ++++++++++++++++++++++++++------
 templates/search.html            |  8 ++++
 4 files changed, 92 insertions(+), 16 deletions(-)

diff --git a/assets/search.js b/assets/search.js
index caa8b72..69a5045 100644
--- a/assets/search.js
+++ b/assets/search.js
@@ -18,6 +18,7 @@ function debouncer(interval, callback) {
     const results = form.querySelector('.live-results');
     const resultPrototype = document.getElementById('search-result-prototype').firstChild;
 
+    let ongoing = false;
     function submit() {
         if (input.value === "") {
             results.classList.remove("show");
@@ -25,8 +26,12 @@ function debouncer(interval, callback) {
             return;
         }
 
+        if (ongoing) return;
+        ongoing = true;
+
+        const query = input.value;
         fetch(
-            "_search?snippet_size=4&limit=3&q=" + encodeURIComponent(input.value),
+            "_search?snippet_size=4&limit=4&q=" + encodeURIComponent(query),
             {
                 headers: {
                     "Accept": "application/json",
@@ -48,13 +53,27 @@ function debouncer(interval, callback) {
                 item.querySelector('.snippet').textContent = hit.snippet;
                 results.appendChild(item);
             })
+
+            if (result.next) {
+                const item = resultPrototype.cloneNode(true);
+                item.querySelector('.link').href = "_search?q=" + encodeURIComponent(query);
+                item.querySelector('.link').setAttribute("data-focusindex", result.hits.length + 1);
+                item.querySelector('.link').innerHTML = "See more results\u2026";
+                results.appendChild(item);
+            }
+
             results.classList.add("show");
+
+            if (input.value !== query) submitter();
+
+            ongoing = false;
         }).catch(err => {
+            ongoing = false;
             console.error(err);
-            alert(err);
+            alert(err); // TODO Better interactive error reporting
         });
     }
-    const submitter = debouncer(200, submit);
+    const submitter = debouncer(300, submit);
 
     input.addEventListener('input', submitter);
 
@@ -85,6 +104,10 @@ function debouncer(interval, callback) {
             ev.preventDefault();
             ev.stopPropagation();
             moveFocus(element, 1);
+        } else if (ev.key === 'Escape') {
+            ev.preventDefault();
+            ev.stopPropagation();
+            document.activeElement && document.activeElement.blur();
         }
     }
 
diff --git a/assets/style.css b/assets/style.css
index e16f4b5..b81c9e6 100644
--- a/assets/style.css
+++ b/assets/style.css
@@ -338,6 +338,7 @@ article ul.search-results {
     width: 100%;
     max-width: 300px;
     box-sizing: border-box;
+    text-overflow: ellipsis;
 }
 
 .search input:focus, .search.focus input {
diff --git a/src/resources/search_resource.rs b/src/resources/search_resource.rs
index c8dc71b..4c5e808 100644
--- a/src/resources/search_resource.rs
+++ b/src/resources/search_resource.rs
@@ -11,34 +11,41 @@ use site::Layout;
 use state::State;
 use web::{Resource, ResponseFuture};
 
-const DEFAULT_LIMIT: i32 = 10;
-const DEFAULT_SNIPPET_SIZE: i32 = 8;
+const DEFAULT_LIMIT: u32 = 10;
+const DEFAULT_SNIPPET_SIZE: u32 = 8;
 
 type BoxResource = Box<Resource + Sync + Send>;
 
 #[derive(Serialize, Deserialize, Default)]
 pub struct QueryParameters {
     q: Option<String>,
-    offset: Option<i32>,
-    limit: Option<i32>,
-    snippet_size: Option<i32>,
+    offset: Option<u32>,
+    limit: Option<u32>,
+    snippet_size: Option<u32>,
 }
 
 impl QueryParameters {
-    pub fn offset(self, offset: i32) -> Self {
+    pub fn offset(self, offset: u32) -> Self {
         Self {
             offset: if offset != 0 { Some(offset) } else { None },
             ..self
         }
     }
 
-    pub fn limit(self, limit: i32) -> Self {
+    pub fn limit(self, limit: u32) -> Self {
         Self {
             limit: if limit != DEFAULT_LIMIT { Some(limit) } else { None },
             ..self
         }
     }
 
+    pub fn snippet_size(self, snippet_size: u32) -> Self {
+        Self {
+            snippet_size: if snippet_size != DEFAULT_SNIPPET_SIZE { Some(snippet_size) } else { None },
+            ..self
+        }
+    }
+
     pub fn into_link(self) -> String {
         let args = serde_urlencoded::to_string(self).expect("Serializing to String cannot fail");
         if args.len() > 0 {
@@ -79,9 +86,9 @@ pub struct SearchResource {
     response_type: ResponseType,
 
     query: Option<String>,
-    limit: i32,
-    offset: i32,
-    snippet_size: i32,
+    limit: u32,
+    offset: u32,
+    snippet_size: u32,
 }
 
 // This is a complete hack, searching for a reasonable design:
@@ -91,9 +98,19 @@ pub enum ResponseType {
 }
 
 impl SearchResource {
-    pub fn new(state: State, query: Option<String>, limit: i32, offset: i32, snippet_size: i32) -> Self {
+    pub fn new(state: State, query: Option<String>, limit: u32, offset: u32, snippet_size: u32) -> Self {
         Self { state, response_type: ResponseType::Html, query, limit, offset, snippet_size }
     }
+
+    fn query_args(&self) -> QueryParameters {
+        QueryParameters {
+            q: self.query.clone(),
+            ..QueryParameters::default()
+        }
+            .offset(self.offset)
+            .limit(self.limit)
+            .snippet_size(self.snippet_size)
+    }
 }
 
 impl Resource for SearchResource {
@@ -132,6 +149,8 @@ impl Resource for SearchResource {
         struct JsonResponse<'a> {
             query: &'a str,
             hits: &'a [models::SearchResult],
+            prev: Option<String>,
+            next: Option<String>,
         }
 
         struct Hit<'a> {
@@ -156,21 +175,44 @@ impl Resource for SearchResource {
         struct Template<'a> {
             query: &'a str,
             hits: &'a [Hit<'a>],
+            prev: Option<String>,
+            next: Option<String>,
         }
 
         // TODO: Show a search "front page" when no query is given:
         let query = self.query.as_ref().map(|x| x.clone()).unwrap_or("".to_owned());
 
-        let data = self.state.search_query(query, self.limit, self.offset, self.snippet_size);
+        let data = self.state.search_query(query, (self.limit + 1) as i32, self.offset as i32, self.snippet_size as i32);
         let head = self.head();
 
         Box::new(data.join(head)
-            .and_then(move |(data, head)| {
+            .and_then(move |(mut data, head)| {
+                let prev = if self.offset > 0 {
+                    Some(self.query_args()
+                        .offset(self.offset.saturating_sub(self.limit))
+                        .into_link()
+                    )
+                } else {
+                    None
+                };
+
+                let next = if data.len() > self.limit as usize {
+                    data.pop();
+                    Some(self.query_args()
+                        .offset(self.offset + self.limit)
+                        .into_link()
+                    )
+                } else {
+                    None
+                };
+
                 match &self.response_type {
                     &ResponseType::Json => Ok(head
                         .with_body(serde_json::to_string(&JsonResponse {
                             query: self.query.as_ref().map(|x| &**x).unwrap_or(""),
                             hits: &data,
+                            prev,
+                            next,
                         }).expect("Should never fail"))
                     ),
                     &ResponseType::Html => Ok(head
@@ -188,6 +230,8 @@ impl Resource for SearchResource {
                                         snippet: &result.snippet,
                                     })
                                     .collect::<Vec<_>>(),
+                                prev,
+                                next,
                             },
                         }.to_string())),
                 }
diff --git a/templates/search.html b/templates/search.html
index bca5d19..c6b64ef 100644
--- a/templates/search.html
+++ b/templates/search.html
@@ -7,6 +7,10 @@
 {{#hits?}}
 <p>Search results for the query <b>{{query}}</b>:</p>
 
+{{#prev}}<nav><ul class="dense"
+    ><li><a rel="prev" href="{{.}}">Previous page</a></li
+></ul></nav>{{/prev}}
+
 <ul class="search-results default-keyboard-focus-control">
     {{#hits}}
     <li class="search-result"><a data-focusindex="{{.index}}" class="link" href="{{.link()}}"><p class="title">{{.title}}</p><p class="snippet">{{.snippet}}</p></a></li>
@@ -14,6 +18,10 @@
 </ul>
 {{/hits}}
 
+{{#next}}<nav><ul class="dense"
+    ><li><a rel="next" href="{{.}}">Next page</a></li
+></ul></nav>{{/next}}
+
 {{^hits?}}
 <p>Your search for <b>{{query}}</b> gave no results.</p>
 {{/hits}}