原始可观察------ a ------- b ------- c ---------- d --------＆gt;。 ...
映射可观察----- A ------- B（完成）
简单的代码如下：
val original = Observable.just('a', 'b', 'c', 'd')
val mapped = original.map(x => x.toUpper)
//how to let `mapped` Observable stop emit event when received 'b' from original?
//do something
mapped.subscribe(x => println(x)) //make it only print A ,B
如何在B这个指定条件下完成映射的observable？
更新takeUntil方法
takeUntil似乎是一个标准答案，但我的编辑显示此方法以Observable[Any]为参数。请参阅定义，
def takeUntil(that: Observable[Any]): Observable[T]
如果我使用以下代码
val original = Observable.just('a', 'b', 'c', 'd').takeUntil(x => x == 'b')
发生编译错误
Error:(74, 64) missing parameter type
val original = Observable.just('a', 'b', 'c', 'd').takeUntil(x => x == 'b')
^
我们使用相同的套餐吗？我的sbt依赖是"com.netflix.rxjava" % "rxjava-scala" % "0.20.7"
答案 0 :(得分：1)
使用class LocationLocationRelationshipsController < ApplicationController
before_action :set_location_location_relationship, only: [:show, :edit, :update, :destroy]
# GET /location_location_relationships
# GET /location_location_relationships.json
def index
@location_location_relationships = LocationLocationRelationship.all
end
# GET /location_location_relationships/1
# GET /location_location_relationships/1.json
def show
end
# GET /location_location_relationships/new
def new
@location_location_relationship = LocationLocationRelationship.new
end
# GET /location_location_relationships/1/edit
def edit
end
# POST /location_location_relationships
# POST /location_location_relationships.json
def create
@location_location_relationship = LocationLocationRelationship.new(location_location_relationship_params)
respond_to do |format|
if @location_location_relationship.save
format.html { redirect_to @location_location_relationship, notice: 'Die Distanz wurde angelegt.' }
format.json { render :show, status: :created, location: @location_location_relationship }
else
format.html { render :new }
format.json { render json: @location_location_relationship.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /location_location_relationships/1
# PATCH/PUT /location_location_relationships/1.json
def update
respond_to do |format|
if @location_location_relationship.update(location_location_relationship_params)
format.html { redirect_to @location_location_relationship, notice: 'Die Distanz wurde aktualisiert.' }
format.json { render :show, status: :ok, location: @location_location_relationship }
else
format.html { render :edit }
format.json { render json: @location_location_relationship.errors, status: :unprocessable_entity }
end
end
end
# DELETE /location_location_relationships/1
# DELETE /location_location_relationships/1.json
def destroy
@location_location_relationship.destroy
respond_to do |format|
format.html { redirect_to location_location_relationships_url, notice: 'Die Distanz wurde gelöscht.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_location_location_relationship
@location_location_relationship = LocationLocationRelationship.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def location_location_relationship_params
params.require(:location_location_relationship).permit(:predecessor_id, :successor_id, :tour, :distance, :sequence, :binary_variable)
end
end
，它完全符合您的需要。