Asked  1 Year ago    Answers:  5   Viewed   4 times

Im working on small website scrapper with cURL.

I decided to use preg_match to find header and article content.

This is my code:

preg_match('@<h2 class="title">(.*?)</h2>@s', $this->website, $this->title);

if(sizeof($this->title) > 1)
    $this->title = trim($this->title[1]); // rewrite first element of array to regular variable

I was experimenting with it and I found, that if there is one match - it returns it in array at index 1, not 0.

Edited question: Why is this 1, not 0? Im doing something wrong?

My server: Apache/2.4.3 (Win32) PHP/5.4.7



The default behaviour of preg_match is to return the entire string which was matched in the result array at index 0, then each matched sub-pattern in subsequent result array indexes. If nothing was matched, the result array is empty. If something is matched, you get the full string that was matched and then any sub-patterns.

Saturday, May 29, 2021

You are missing the /ims flag at the end of your regex. Otherwise . will not match line breaks (as in your first paragraph). Actually /s would suffice, but I'm always using all three for simplicity.

Also, preg_match works for many simple cases. But if you are attempting any more complex extractions, then consider alternating to phpQuery or QueryPath which allow for:

foreach (qp($html)->find("p") as $p)  { print $p->text(); }
Friday, May 28, 2021

Use preg_quote to quote regular expression characters.

Like this:

preg_quote($theKeyword, '/');

Where '/' is the delimiter in your regular expression.

Friday, May 28, 2021
preg_match('~"http://(.*)"~iU', $code, $matches);

Your issue was you need delimiters (I chose ~) to use with the pattern. See the preg_match() man page for more information.

Friday, June 11, 2021

It may occur because:

  • DbContext configured with an incorrect connection string
  • The entity specified is actually not mapped in configuration
Thursday, July 29, 2021

Add the virtual keyword before your related entities:

public class Order
    public int Id { get; set; }

    public virtual Patient Patient { get; set; }

    public virtual CertificationPeriod CertificationPeriod { get; set; }

    public virtual Agency Agency { get; set; }

    public virtual Diagnosis PrimaryDiagnosis { get; set; }

    public virtual OrderApprovalStatus ApprovalStatus { get; set; }

    public virtual User Approver { get; set; }

    public virtual User Submitter { get; set; }

    public DateTime ApprovalDate { get; set; }

    public DateTime SubmittedDate { get; set; }
    public Boolean IsDeprecated { get; set; }

You might end up with a A circular reference was detected while serializing an object... error if your objects have references of each other. In that case, you will need to create a ViewModel or something similar to overcome this problem. Or use LINQ to project an anonymous object.

Sunday, December 26, 2021
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