空间站跟踪网页响应控制: Wolfram语言 11 的新功能

空间站跟踪网页响应控制

通过返回一个 HTTPResponse 可以从一个云对象控制 HTTP 响应的确切特征. 错误情形可用 HTTPErrorResponse 处理.

定义函数，找到离国际空间站当前位置最近的城市. 空间站移动迅速，因而结果也快速变化.

显示完整的 Wolfram 语言输入

In[1]:=

issLocationDisplay[] :=
 
 Module[{pos, posline, country, city, distance}, {pos, posline} = 
   SatelliteData[
    Entity["Satellite", "25544"], {"Position", "PositionLine"}];
  country = First[GeoNearest["Country", pos]];
  distance = Round[GeoDistance[pos, country], 0.1];
  Panel@Column[{Row[{"ISS Position: ", 
       Style[If[distance <= Quantity[0., "Miles"], 
         "over " <> First[GeoNearest["City", pos]]["Name"] <> ", " <> 
          country["Name"], 
         ToString[
          Row[{"over the open sea ", distance, " from ", 
            country["Name"]}]]], Darker[Blue]]}, 
      BaseStyle -> 
       Directive["FontFamily" -> "SansSerif", RGBColor["#497CA4"], 
        Larger, Bold]], 
     GeoGraphics[{Gray, Thickness[.005], 
       Arrowheads[{{0.05, 0.4}, {0.05, 0.13}}], Arrow @@ posline, Red,
        PointSize[.01], Point[pos], Opacity[.1], Black, 
       GeoVisibleRegion[pos]}, GeoCenter -> pos, GeoRange -> "World", 
      ImageSize -> 600]}]]

In[2]:=

issLocationDisplay[]

Out[2]=

部署每次都作计算的云对象，用 HTTPResponse 指出内容类型，并指定一个头，告诉浏览器不要缓存结果.

In[3]:=

obj = CloudDeploy[
  Delayed[HTTPResponse[
    ExportString[issLocationDisplay[], "PNG"], <|
     "ContentType" -> "image/png", 
     "Headers" -> {"Cache-Control" -> "no-cache"}|>]],
  CloudObject["iss-location"], Permissions -> "Public"]

Out[3]=

禁止某些用户使用云对象，返回 HTTPErrorResponse.

In[4]:=

obj = CloudDeploy[Delayed[
   If[MemberQ[{"badapple@example.com", "blackhat@example.com", 
      "spammer@example.com"}, $WolframID],
    HTTPErrorResponse[403],
    HTTPResponse[
     issLocationDisplay[], <|
      "Headers" -> {"Cache-Control" -> "no-cache"}|>]
    ]], CloudObject["iss-location"], Permissions -> "Public"]

Out[4]=

Wolfram 语言™

空间站跟踪网页响应控制

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