Nokogiri實施協助

Question

<?xml version="1.0" encoding="UTF-8" standalone="true"?> 
<hierarchy rotation="0"> 
<node class="android.widget.FrameLayout" bounds="[0,0][768,1184]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="" text="" index="0"> 
<node class="android.widget.FrameLayout" bounds="[0,0][768,1184]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/panel_holder" text="" index="0"> 
<node class="android.widget.FrameLayout" bounds="[0,0][768,1184]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/notification_panel" text="" index="0"> 
<node class="android.widget.FrameLayout" bounds="[0,0][768,1184]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/notification_container_parent" text="" index="0"> 
<node class="android.widget.RelativeLayout" bounds="[0,0][768,120]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="true" enabled="true" clickable="true" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/header" text="" index="1"> 
<node class="android.widget.LinearLayout" bounds="[48,8][153,62]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/clock" text="" index="0"> 
<node class="android.widget.TextView" bounds="[48,21][103,59]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/time_view" text="5:28" index="0"/> 
<node class="android.widget.TextView" bounds="[103,21][153,59]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/am_pm_view" text=" PM" index="1"/> 
</node> 
<node class="android.widget.FrameLayout" bounds="[16,62][260,100]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/date_group" text="" index="1"> 
<node class="android.widget.TextView" bounds="[48,62][260,100]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/date_expanded" text="Monday, March 6" index="0"/> 
</node> 
<node class="android.widget.LinearLayout" bounds="[542,0][658,120]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/system_icons_super_container" text="" index="3"> 
<node class="android.widget.FrameLayout" bounds="[542,35][650,85]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/system_icons_container" text="" index="0"> 
<node class="android.widget.LinearLayout" bounds="[542,35][650,85]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/system_icons" text="" index="0"> 
<node class="android.widget.LinearLayout" bounds="[547,43][631,77]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/signal_cluster" text="" index="1"> 
<node class="android.widget.FrameLayout" bounds="[547,43][583,77]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="Wifi signal full." package="com.android.systemui" resource-id="com.android.systemui:id/wifi_combo" text="" index="0"> 
<node class="android.widget.ImageView" bounds="[547,43][583,77]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/wifi_signal" text="" index="0"/> 
</node> 
<node class="android.widget.LinearLayout" bounds="[583,43][617,77]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/mobile_signal_group" text="" index="1"> 
<node class="android.widget.FrameLayout" bounds="[583,43][617,77]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="3G Phone two bars." package="com.android.systemui" resource-id="com.android.systemui:id/mobile_combo" text="" index="0"> 
<node class="android.widget.ImageView" bounds="[583,43][617,77]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/mobile_signal" text="" index="0"/> 
</node> 
</node> 
</node> 
<node class="android.view.View" bounds="[631,45][650,74]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="Battery 100 percent." package="com.android.systemui" resource-id="com.android.systemui:id/battery" text="" index="2"/> 
</node> 
</node> 
</node> 
<node class="android.widget.FrameLayout" bounds="[658,0][726,120]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/multi_user_switch" text="" index="4"> 
<node class="android.widget.ImageView" bounds="[670,38][714,82]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/multi_user_avatar" text="" index="0"/> 
</node> 
</node> 
</node> 
</node> 
<node class="android.view.View" bounds="[0,0][768,1184]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/scrim_behind" text="" index="1"/> 
<node class="android.view.View" bounds="[0,0][768,1184]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/scrim_in_front" text="" index="2"/> 
<node class="android.widget.FrameLayout" bounds="[0,0][768,50]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/status_bar" text="" index="3"> 
<node class="android.widget.LinearLayout" bounds="[0,0][768,50]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/status_bar_contents" text="" index="0"> 
<node class="android.widget.FrameLayout" bounds="[12,0][575,50]" selected="false" password="false" long-clickable="false" scrollable="false" focused="false" focusable="false" enabled="true" clickable="false" checked="false" checkable="false" content-desc="" package="com.android.systemui" resource-id="com.android.systemui:id/notification_icon_area" text="" index="0"/> 
</node> 
</node> 
</node> 
</hierarchy> 

我有一個XML文件，並試圖提取「text」屬性，例如「ana.zx」，並將其放置在不同的文件中，或者將其轉換爲字符串。

我設法達到了將文件保存到存儲並打開它的地步，但我還沒有弄清楚如何使用Nokogiri來提取該屬性。

這是我到目前爲止有：

doc = File.open("window_dump.xml") { |f| Nokogiri::XML(f)} 

Answer 1

你的XML是無效的。 XML規範非常嚴格，所以文檔必須是有效的，不像HTML是小狗友好的。

這裏是引入nokogiri發現的錯誤：

# => [#<Nokogiri::XML::SyntaxError: XML declaration allowed only at the start of the document>, 
#  #<Nokogiri::XML::SyntaxError: Opening and ending tag mismatch: node line 4 and hierarchy>, 
#  #<Nokogiri::XML::SyntaxError: Premature end of data in tag hierarchy line 3>] 

解析文檔使用的返回值的errors方法，看看有什麼引入nokogiri不得不做解析文檔後。如果出現錯誤，Nokogiri可能需要修改文檔才能返回某些內容，並且這些更改後的節點可以隱藏信息。在您的文檔中，它在文本的早期階段，因此您可能會失去對所有後續子節點的訪問權限。

如果errors顯示存在問題，則在需要更多信息時使用XML驗證程序。至少我會將文件拖入Vim並讓它重新格式化文檔，以便我可以檢查其縮進/嵌套，因爲通常問題是由於缺少結束標記。

而且，這裏是如何，我們通常打開和分析使用引入nokogiri文件：

doc = Nokogiri::XML(File.open('path/to/file.xml')) 

引入nokogiri將讀取並關閉文件給你，讓使用塊是不必要的。