Provide build info as json string

Docs.rs will provide build as json from following URL:

`https://docs.rs/crate/<CRATE_NAME>/<CRATE_VERSION>/builds.json`.

A get request to this URL will return a list of build attempts. First
object in this list will always contain latest build attempt. This
object will contain following fields:

Example output of `https://docs.rs/crate/rand/0.3.15/builds.json`:

```json
[
  {
    "build_status":true,
    "build_time":"2016-12-29T10:10:49Z",
    "build_time_relative":"Dec 29, 2016",
    "cratesfyi_version":"cratesfyi 0.2.3 (eea831c 2016-12-29)",
    "id":1,
    "output":null,
    "rustc_version":"rustc 1.15.0-nightly (71c06a56a 2016-12-18)"
  }
]
```

`build_status` is `true` if docs.rs successfully built documentation of
a crate and `false` if docs.rs failed to build or a crate doesn't have
any documentation.

This list will contain zero elements if requested crate doesn't exists
in docs.rs.

Fixes: #87
Ref: rust-lang/crates.io#459
Ref: rust-lang/crates.io#506

Author: onur

src/web/builds.rs

@@ -39,6 +39,8 @@ impl ToJson for Build {
                  self.cratesfyi_version.to_json());
         m.insert("build_status".to_owned(), self.build_status.to_json());
         m.insert("build_time".to_owned(),
+                 format!("{}", time::at(self.build_time).rfc3339()).to_json());
+        m.insert("build_time_relative".to_owned(),
                  duration_to_str(self.build_time).to_json());
         m.insert("output".to_owned(), self.output.to_json());
         m.to_json()
@@ -106,14 +108,37 @@ pub fn build_list_handler(req: &mut Request) -> IronResult<Response> {
         build_list.push(build);
     }
 
-    let builds_page = BuildsPage {
-        metadata: MetaData::from_crate(&conn, &name, &version),
-        builds: build_list,
-        build_details: build_details,
-    };
+    if req.url.path.join("/").ends_with(".json") {
+        use iron::status;
+        use iron::headers::{Expires,
+                            HttpDate,
+                            CacheControl,
+                            CacheDirective,
+                            ContentType,
+                            AccessControlAllowOrigin};
+
+        // Remove build output from build list for json output
+        for build in build_list.as_mut_slice() {
+            build.output = None;
+        }
 
-    Page::new(builds_page)
-        .set_true("show_package_navigation")
-        .set_true("package_navigation_builds_tab")
-        .to_resp("builds")
+        let mut resp = Response::with((status::Ok, build_list.to_json().to_string()));
+        resp.headers.set(ContentType("application/json".parse().unwrap()));
+        resp.headers.set(Expires(HttpDate(time::now())));
+        resp.headers.set(CacheControl(vec![CacheDirective::NoCache,
+                                           CacheDirective::NoStore,
+                                           CacheDirective::MustRevalidate]));
+        resp.headers.set(AccessControlAllowOrigin::Any);
+        Ok(resp)
+    } else {
+        let builds_page = BuildsPage {
+            metadata: MetaData::from_crate(&conn, &name, &version),
+            builds: build_list,
+            build_details: build_details,
+        };
+        Page::new(builds_page)
+            .set_true("show_package_navigation")
+            .set_true("package_navigation_builds_tab")
+            .to_resp("builds")
+    }
 }

src/web/mod.rs

@@ -116,6 +116,7 @@ impl CratesfyiHandler {
         router.get("/crate/:name/:version", crate_details::crate_details_handler);
         router.get("/crate/:name/:version/", crate_details::crate_details_handler);
         router.get("/crate/:name/:version/builds", builds::build_list_handler);
+        router.get("/crate/:name/:version/builds.json", builds::build_list_handler);
         router.get("/crate/:name/:version/builds/:id", builds::build_list_handler);
         router.get("/crate/:name/:version/source/", source::source_browser_handler);
         router.get("/crate/:name/:version/source/*", source::source_browser_handler);

templates/builds.hbs

@@ -30,7 +30,7 @@ $ cratesfyi ...
         <div class="pure-u-1 pure-u-sm-1-24 build"><i class="fa fa-{{#if build_status }}check{{else}}close{{/if}}"></i></div>
         <div class="pure-u-1 pure-u-sm-10-24">{{rustc_version}}</div>
         <div class="pure-u-1 pure-u-sm-10-24">{{cratesfyi_version}}</div>
-        <div class="pure-u-1 pure-u-sm-3-24 date">{{build_time}}</div>
+        <div class="pure-u-1 pure-u-sm-3-24 date">{{build_time_relative}}</div>
       </div>
     </a>
     </li>