[milo] Refactor all html knowledge out of backends.

milo/buildsource/buildbucket/html.go

-// Copyright 2016 The LUCI Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package buildbucket
-
-import (
-        "errors"
-        "net/http"
-
-        "golang.org/x/net/context"
-
-        "github.com/julienschmidt/httprouter"
-        "github.com/luci/luci-go/milo/common"
-        "github.com/luci/luci-go/server/router"
-        "github.com/luci/luci-go/server/templates"
-)
-
-func parseBuilderQuery(c context.Context, r *http.Request, p httprouter.Params) (
-        query builderQuery, err error) {
-
-        query.Bucket = p.ByName("bucket")
-        if query.Bucket == "" {
-                err = errors.New("No bucket")
-                return
-        }
-
-        query.Builder = p.ByName("builder")
-        if query.Builder == "" {
-                err = errors.New("No builder")
-                return
-        }
-
-        // limit is a name of the query string parameter for specifying
-        // maximum number of builds to show.
-        query.Limit, err = common.GetLimit(r)
-        return
-}
-
-// BuilderHandler renders the builder view page.
-// Note: The builder html template contains self links to "?limit=123", which could
-// potentially override any other request parameters set.
-func BuilderHandler(c *router.Context) {
-        query, err := parseBuilderQuery(c.Context, c.Request, c.Params)
-        if err != nil {
-                common.ErrorPage(c, http.StatusBadRequest, err.Error())
-                return
-        }
-
-        result, err := builderImpl(c.Context, query)
-        if err != nil {
-                common.ErrorPage(c, http.StatusInternalServerError, err.Error())
-                return
-        }
-
-        templates.MustRender(c.Context, c.Writer, "pages/builder.html", templates.Args{
-                "Builder": result,
-        })
-}