Functional programming 如何为显示缓存网络数据的Android屏幕使用反应式编程？

我正试图找出如何将函数式编程应用到我正在Android应用程序中编写的功能上。阅读之后，反应式编程似乎非常适合此功能

场景：

-i-----------i---------------> screen_initialization: user goes into screen
-N-----------Y---------------> check_cache: map() gives N if data not found in db, Y otherwise
-q---------------------------> do_refresh_cache1: filter() out anything by N
----------------r------------> refresh_button_clicks
-q--------------r------------> do_refresh_cache2: merge() streams screen_initialization and do_refresh_cache1

-q--------------r------------> clear_cache: map() do_refresh_cache2, clearing datBAase
-cba|-----------cbad|--------> get_ids: flatMap() call API1 for ids (e.g. q results in 3 ids: a, b, c)
-CBA|-----------CBAD|--------> get_details: map() calls API2 for each id to get details
-CBA|-----------CBAD|--------> persist: map() persists each value (A, B, C, etc.) in the datBAase cache
----P---------------P--------> emit_ready: toPromise() emits a signal when we have details for each id

-q--------------r------------> do_load_from_cache: merge() streams screen_initialization and do_refresh_cache1
----P---------------P--------> wait_for_ready: fromPromise() waits for a signal when we have details for each id
----CBA|------------CBAD|----> load_from_cache: flatMap() query database for id details when wait_for_ready promise fullfilled 
-------ABC|-------------ABCD|> display: somehow sort the results

-s--------------s------------> show_spinner: map() do_refresh_cache2 to show a spinner while making network calls
----------h-----------------h> hide_spinner: hide spinner when display stream finishes

用户点击设置

列表中填充了一组从RESTAPI调用缓存（在磁盘上）的值

用户可以通过单击刷新按钮刷新缓存

要从REST API调用中获取值，有两个阶段：

API1-返回ID（需要两个HTTP请求头，“日期”和“授权”用于身份验证）

API2-给定id，返回有关该id的详细信息（无身份验证）

由于我是反应式编程的新手，我想我应该从以反应式编程风格编写伪代码开始。然后我必须将伪代码翻译成适合Android的实际Java代码。要做到这一点，我需要知道哪种反应式编程库最适合我的任务

为了开始编写伪代码，我将使用@andré-staltz在中使用的语法：

用户操作：

-i-----------i---------------> screen_initialization: user goes into screen
-N-----------Y---------------> check_cache: map() gives N if data not found in db, Y otherwise
-q---------------------------> do_refresh_cache1: filter() out anything by N
----------------r------------> refresh_button_clicks
-q--------------r------------> do_refresh_cache2: merge() streams screen_initialization and do_refresh_cache1

-q--------------r------------> clear_cache: map() do_refresh_cache2, clearing datBAase
-cba|-----------cbad|--------> get_ids: flatMap() call API1 for ids (e.g. q results in 3 ids: a, b, c)
-CBA|-----------CBAD|--------> get_details: map() calls API2 for each id to get details
-CBA|-----------CBAD|--------> persist: map() persists each value (A, B, C, etc.) in the datBAase cache
----P---------------P--------> emit_ready: toPromise() emits a signal when we have details for each id

-q--------------r------------> do_load_from_cache: merge() streams screen_initialization and do_refresh_cache1
----P---------------P--------> wait_for_ready: fromPromise() waits for a signal when we have details for each id
----CBA|------------CBAD|----> load_from_cache: flatMap() query database for id details when wait_for_ready promise fullfilled 
-------ABC|-------------ABCD|> display: somehow sort the results

-s--------------s------------> show_spinner: map() do_refresh_cache2 to show a spinner while making network calls
----------h-----------------h> hide_spinner: hide spinner when display stream finishes

缓存：

-i-----------i---------------> screen_initialization: user goes into screen
-N-----------Y---------------> check_cache: map() gives N if data not found in db, Y otherwise
-q---------------------------> do_refresh_cache1: filter() out anything by N
----------------r------------> refresh_button_clicks
-q--------------r------------> do_refresh_cache2: merge() streams screen_initialization and do_refresh_cache1

-q--------------r------------> clear_cache: map() do_refresh_cache2, clearing datBAase
-cba|-----------cbad|--------> get_ids: flatMap() call API1 for ids (e.g. q results in 3 ids: a, b, c)
-CBA|-----------CBAD|--------> get_details: map() calls API2 for each id to get details
-CBA|-----------CBAD|--------> persist: map() persists each value (A, B, C, etc.) in the datBAase cache
----P---------------P--------> emit_ready: toPromise() emits a signal when we have details for each id

-q--------------r------------> do_load_from_cache: merge() streams screen_initialization and do_refresh_cache1
----P---------------P--------> wait_for_ready: fromPromise() waits for a signal when we have details for each id
----CBA|------------CBAD|----> load_from_cache: flatMap() query database for id details when wait_for_ready promise fullfilled 
-------ABC|-------------ABCD|> display: somehow sort the results

-s--------------s------------> show_spinner: map() do_refresh_cache2 to show a spinner while making network calls
----------h-----------------h> hide_spinner: hide spinner when display stream finishes

加载：

-i-----------i---------------> screen_initialization: user goes into screen
-N-----------Y---------------> check_cache: map() gives N if data not found in db, Y otherwise
-q---------------------------> do_refresh_cache1: filter() out anything by N
----------------r------------> refresh_button_clicks
-q--------------r------------> do_refresh_cache2: merge() streams screen_initialization and do_refresh_cache1

-q--------------r------------> clear_cache: map() do_refresh_cache2, clearing datBAase
-cba|-----------cbad|--------> get_ids: flatMap() call API1 for ids (e.g. q results in 3 ids: a, b, c)
-CBA|-----------CBAD|--------> get_details: map() calls API2 for each id to get details
-CBA|-----------CBAD|--------> persist: map() persists each value (A, B, C, etc.) in the datBAase cache
----P---------------P--------> emit_ready: toPromise() emits a signal when we have details for each id

-q--------------r------------> do_load_from_cache: merge() streams screen_initialization and do_refresh_cache1
----P---------------P--------> wait_for_ready: fromPromise() waits for a signal when we have details for each id
----CBA|------------CBAD|----> load_from_cache: flatMap() query database for id details when wait_for_ready promise fullfilled 
-------ABC|-------------ABCD|> display: somehow sort the results

-s--------------s------------> show_spinner: map() do_refresh_cache2 to show a spinner while making network calls
----------h-----------------h> hide_spinner: hide spinner when display stream finishes

UI:

-i-----------i---------------> screen_initialization: user goes into screen
-N-----------Y---------------> check_cache: map() gives N if data not found in db, Y otherwise
-q---------------------------> do_refresh_cache1: filter() out anything by N
----------------r------------> refresh_button_clicks
-q--------------r------------> do_refresh_cache2: merge() streams screen_initialization and do_refresh_cache1

-q--------------r------------> clear_cache: map() do_refresh_cache2, clearing datBAase
-cba|-----------cbad|--------> get_ids: flatMap() call API1 for ids (e.g. q results in 3 ids: a, b, c)
-CBA|-----------CBAD|--------> get_details: map() calls API2 for each id to get details
-CBA|-----------CBAD|--------> persist: map() persists each value (A, B, C, etc.) in the datBAase cache
----P---------------P--------> emit_ready: toPromise() emits a signal when we have details for each id

-q--------------r------------> do_load_from_cache: merge() streams screen_initialization and do_refresh_cache1
----P---------------P--------> wait_for_ready: fromPromise() waits for a signal when we have details for each id
----CBA|------------CBAD|----> load_from_cache: flatMap() query database for id details when wait_for_ready promise fullfilled 
-------ABC|-------------ABCD|> display: somehow sort the results

-s--------------s------------> show_spinner: map() do_refresh_cache2 to show a spinner while making network calls
----------h-----------------h> hide_spinner: hide spinner when display stream finishes

问题：

-i-----------i---------------> screen_initialization: user goes into screen
-N-----------Y---------------> check_cache: map() gives N if data not found in db, Y otherwise
-q---------------------------> do_refresh_cache1: filter() out anything by N
----------------r------------> refresh_button_clicks
-q--------------r------------> do_refresh_cache2: merge() streams screen_initialization and do_refresh_cache1

-q--------------r------------> clear_cache: map() do_refresh_cache2, clearing datBAase
-cba|-----------cbad|--------> get_ids: flatMap() call API1 for ids (e.g. q results in 3 ids: a, b, c)
-CBA|-----------CBAD|--------> get_details: map() calls API2 for each id to get details
-CBA|-----------CBAD|--------> persist: map() persists each value (A, B, C, etc.) in the datBAase cache
----P---------------P--------> emit_ready: toPromise() emits a signal when we have details for each id

-q--------------r------------> do_load_from_cache: merge() streams screen_initialization and do_refresh_cache1
----P---------------P--------> wait_for_ready: fromPromise() waits for a signal when we have details for each id
----CBA|------------CBAD|----> load_from_cache: flatMap() query database for id details when wait_for_ready promise fullfilled 
-------ABC|-------------ABCD|> display: somehow sort the results

-s--------------s------------> show_spinner: map() do_refresh_cache2 to show a spinner while making network calls
----------h-----------------h> hide_spinner: hide spinner when display stream finishes

Psuedo代码：如何使我的Psuedo代码符合要求

真实代码：RxJava、RxAndroid或其他一些反应式编程库中应该使用哪些方法将psuedo代码转换为Android的真实代码

我建议您阅读（其中一个与专门改装和Sqlbrite相关，但它可以很容易地应用于任何其他方面）。此+

flatMap

用于将

API1

的结果转换为

API2

的内容应该会让您有很多工作要做。我建议您阅读（这一个与专门改装和Sqlbrite相关，但它可以很容易地应用于任何其他方面）。这个+

flatMap

用于将

API1

的结果转换为

API2

的方法应该会让您有很多工作要做。