Cómo scrapear un blog en C#
Usemos Iron WebScraper para extraer el contenido de un Blog usando C# o VB.NET.
Este tutorial muestra cómo un blog de WordPress(o similar) pueden volver a convertirse en contenido mediante .NET
public class BlogScraper : WebScraper
{
/// <summary>
/// Override this method initializes your web-scraper.
/// Important tasks will be to Request at least one start url... and set allowed/banned domain or url patterns.
/// </summary>
public override void Init()
{
License.LicenseKey = " LicenseKey ";
this.LoggingLevel = WebScraper.LogLevel.All;
this.WorkingDirectory = AppSetting.GetAppRoot() + @"\BlogSample\Output\";
EnableWebCache(new TimeSpan(1, 30, 30));
this.Request("http://blogSite.com/", Parse);
}
}public class BlogScraper : WebScraper
{
/// <summary>
/// Override this method initializes your web-scraper.
/// Important tasks will be to Request at least one start url... and set allowed/banned domain or url patterns.
/// </summary>
public override void Init()
{
License.LicenseKey = " LicenseKey ";
this.LoggingLevel = WebScraper.LogLevel.All;
this.WorkingDirectory = AppSetting.GetAppRoot() + @"\BlogSample\Output\";
EnableWebCache(new TimeSpan(1, 30, 30));
this.Request("http://blogSite.com/", Parse);
}
}Public Class BlogScraper
Inherits WebScraper
''' <summary>
''' Override this method initializes your web-scraper.
''' Important tasks will be to Request at least one start url... and set allowed/banned domain or url patterns.
''' </summary>
Public Overrides Sub Init()
License.LicenseKey = " LicenseKey "
Me.LoggingLevel = WebScraper.LogLevel.All
Me.WorkingDirectory = AppSetting.GetAppRoot() & "\BlogSample\Output\"
EnableWebCache(New TimeSpan(1, 30, 30))
Me.Request("http://blogSite.com/", Parse)
End Sub
End ClassVB C#
Como de costumbre, creamos un Scraper y heredamos de la clase WebScraper. En este caso es "BlogScraper".
Establecemos un directorio de trabajo a "\BlogSample\Output\" que es donde todos los archivos de salida y la memoria caché puede ir.
A continuación, activamos la caché web para guardar las páginas solicitadas en la carpeta de caché "WebCache".
Ahora vamos a escribir una función de análisis sintáctico:
/// <summary>
/// Override this method to create the default Response handler for your web scraper.
/// If you have multiple page types, you can add additional similar methods.
/// </summary>
/// <param name="response">The http Response object to parse</param>
public override void Parse(Response response)
{
foreach (var link in response.Css("div.section-nav > ul > li > a "))
{
switch(link.TextContentClean)
{
case "Reviews":
{
}break;
case "Science":
{
}break;
default:
{
// Save Result to File
Scrape(new ScrapedData() { { "Title", link.TextContentClean } }, "BlogScraper.Jsonl");
}
break;
}
}
}/// <summary>
/// Override this method to create the default Response handler for your web scraper.
/// If you have multiple page types, you can add additional similar methods.
/// </summary>
/// <param name="response">The http Response object to parse</param>
public override void Parse(Response response)
{
foreach (var link in response.Css("div.section-nav > ul > li > a "))
{
switch(link.TextContentClean)
{
case "Reviews":
{
}break;
case "Science":
{
}break;
default:
{
// Save Result to File
Scrape(new ScrapedData() { { "Title", link.TextContentClean } }, "BlogScraper.Jsonl");
}
break;
}
}
}''' <summary>
''' Override this method to create the default Response handler for your web scraper.
''' If you have multiple page types, you can add additional similar methods.
''' </summary>
''' <param name="response">The http Response object to parse</param>
Public Overrides Sub Parse(ByVal response As Response)
For Each link In response.Css("div.section-nav > ul > li > a ")
Select Case link.TextContentClean
Case "Reviews"
Case "Science"
Case Else
' Save Result to File
Scrape(New ScrapedData() From {
{ "Title", link.TextContentClean }
},
"BlogScraper.Jsonl")
End Select
Next link
End SubVB C#
Dentro del método parse; analizamos el menú superior para obtener todos los enlaces a todas las páginas de categorías(Cine, Ciencia, Críticas, etc.)
A continuación, cambiamos a un método de análisis adecuado basado en la categoría del enlace.
Preparemos nuestro modelo de objetos para la Página de Ciencia:
/// <summary>
/// ScienceModel
/// </summary>
public class ScienceModel
{
/// <summary>
/// Gets or sets the title.
/// </summary>
/// <value>
/// The title.
/// </value>
public string Title { get; set; }
/// <summary>
/// Gets or sets the author.
/// </summary>
/// <value>
/// The author.
/// </value>
public string Author { get; set; }
/// <summary>
/// Gets or sets the date.
/// </summary>
/// <value>
/// The date.
/// </value>
public string Date { get; set; }
/// <summary>
/// Gets or sets the image.
/// </summary>
/// <value>
/// The image.
/// </value>
public string Image { get; set; }
/// <summary>
/// Gets or sets the text.
/// </summary>
/// <value>
/// The text.
/// </value>
public string Text { get; set; }
}/// <summary>
/// ScienceModel
/// </summary>
public class ScienceModel
{
/// <summary>
/// Gets or sets the title.
/// </summary>
/// <value>
/// The title.
/// </value>
public string Title { get; set; }
/// <summary>
/// Gets or sets the author.
/// </summary>
/// <value>
/// The author.
/// </value>
public string Author { get; set; }
/// <summary>
/// Gets or sets the date.
/// </summary>
/// <value>
/// The date.
/// </value>
public string Date { get; set; }
/// <summary>
/// Gets or sets the image.
/// </summary>
/// <value>
/// The image.
/// </value>
public string Image { get; set; }
/// <summary>
/// Gets or sets the text.
/// </summary>
/// <value>
/// The text.
/// </value>
public string Text { get; set; }
}''' <summary>
''' ScienceModel
''' </summary>
Public Class ScienceModel
''' <summary>
''' Gets or sets the title.
''' </summary>
''' <value>
''' The title.
''' </value>
Public Property Title() As String
''' <summary>
''' Gets or sets the author.
''' </summary>
''' <value>
''' The author.
''' </value>
Public Property Author() As String
''' <summary>
''' Gets or sets the date.
''' </summary>
''' <value>
''' The date.
''' </value>
Public Property [Date]() As String
''' <summary>
''' Gets or sets the image.
''' </summary>
''' <value>
''' The image.
''' </value>
Public Property Image() As String
''' <summary>
''' Gets or sets the text.
''' </summary>
''' <value>
''' The text.
''' </value>
Public Property Text() As String
End ClassVB C#
Ahora vamos a implementar un scrape de una sola página:
/// <summary>
/// Parses the reviews.
/// </summary>
/// <param name="response">The response.</param>
public void ParseReviews(Response response)
{
// List of Science Link
var scienceList = new List<ScienceModel>();
foreach (var postBox in response.Css("section.main > div > div.post-list"))
{
var item = new ScienceModel();
item.Title = postBox.Css("h1.headline > a")[0].TextContentClean;
item.Author = postBox.Css("div.author > a")[0].TextContentClean;
item.Date = postBox.Css("div.time > a")[0].TextContentClean;
item.Image = postBox.Css("div.image-wrapper.default-state > img")[0].Attributes ["src"];
item.Text = postBox.Css("div.summary > p")[0].TextContentClean;
scienceList.Add(item);
}
Scrape(scienceList, "BlogScience.Jsonl");
}/// <summary>
/// Parses the reviews.
/// </summary>
/// <param name="response">The response.</param>
public void ParseReviews(Response response)
{
// List of Science Link
var scienceList = new List<ScienceModel>();
foreach (var postBox in response.Css("section.main > div > div.post-list"))
{
var item = new ScienceModel();
item.Title = postBox.Css("h1.headline > a")[0].TextContentClean;
item.Author = postBox.Css("div.author > a")[0].TextContentClean;
item.Date = postBox.Css("div.time > a")[0].TextContentClean;
item.Image = postBox.Css("div.image-wrapper.default-state > img")[0].Attributes ["src"];
item.Text = postBox.Css("div.summary > p")[0].TextContentClean;
scienceList.Add(item);
}
Scrape(scienceList, "BlogScience.Jsonl");
}''' <summary>
''' Parses the reviews.
''' </summary>
''' <param name="response">The response.</param>
Public Sub ParseReviews(ByVal response As Response)
' List of Science Link
Dim scienceList = New List(Of ScienceModel)()
For Each postBox In response.Css("section.main > div > div.post-list")
Dim item = New ScienceModel()
item.Title = postBox.Css("h1.headline > a")(0).TextContentClean
item.Author = postBox.Css("div.author > a")(0).TextContentClean
item.Date = postBox.Css("div.time > a")(0).TextContentClean
item.Image = postBox.Css("div.image-wrapper.default-state > img")(0).Attributes ("src")
item.Text = postBox.Css("div.summary > p")(0).TextContentClean
scienceList.Add(item)
Next postBox
Scrape(scienceList, "BlogScience.Jsonl")
End SubVB C#
Una vez creado nuestro modelo, podemos analizar el objeto de respuesta para desglosar sus elementos principales(título, autor, fecha, imagen, texto)
A continuación, guardamos el resultado en un archivo independiente utilizando Raspar(objeto, fileName).
Haga clic aquí para ver el tutorial completo de Ahmed sobre el uso de IronWebscraper
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Ahmed Aboelmagd
Arquitecto de soluciones de software .NET en una empresa multinacional de TI
Ahmed es un especialista certificado en tecnología Microsoft con más de 10 años de experiencia en TI y desarrollo de software. Ha trabajado en diversas empresas y ahora es director nacional de una multinacional de TI.
Ahmed lleva más de un año trabajando con IronPDF e IronWebScraper, utilizándolos en múltiples proyectos con su empresa.
