PHP Notes: Use of Image Processing in Articles_PHP Tutorial-PHP Tutorial-php.cn

PHP Notes: Use of Image Processing in Articles_PHP Tutorial

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Release： 2016-07-21 15:12:14

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array_diff($arr1,$arr2)
One of the php array functions, used to calculate the difference set of arrays.
Regular matching html image tags
Images added with sinaeditor One of the usages of deletion operation
, I used this function in the process of publishing an article using Sina editor tonight.
Used this function

Problem description:

There are several pictures in the article. They will be automatically uploaded to the picture directory of the website during the process of adding the article.
If the pictures are deleted during the process of modifying the article, then although the code (already stored Database);
has deleted the data tags. Tags similar to . But the image files still exist on the
website. This Sometimes it needs some processing

How to deal with it:

First: Get the original article content from the database
Get the file name of the image from it
Using regular expressions

The method is as follows

Copy the codeThe code is as follows:

public function getimgsinarticle($content) 
 {
 $temp = array();
 $imgs = array();
 preg_match_all('/http[^d]*[d]+[.](jpg|gif|png )/',$content,$temp);
 $temp = $temp[0];
 if(!empty($temp[0]))
 {
 for($i= 0;$i {
 $imgs[$i] = pathinfo($temp[$i]);
 $imgs[$i] = $imgs [$i]['basename'];
 }
 return $imgs;
 }
 else
 {
 return false;
 }
 }
 

Explain the regular rules, first match the four letters of http and then match a number of non-numeric characters. Match at least one numeric character
, match one dot (.), and match jpg or gif or The png end is searched from $congtent. The result is stored in $temp.
Save the pictures in the original data in the database in the array. Name it $oldimgs
I think this place should be improved. After saving It prints out a two-dimensional array. It is a bit troublesome to use
Note: My picture name is similar to this: "201111291322589013.jpg"

Second step:
The method to find all the images from the content submitted by the user is as above. Get the second array and name it $newimgs
The method to find the difference between arr1 and arr2 is as follows
--that is It says that if the picture in the original data does not exist in the user's newly submitted content, then the picture will be deleted.

Copy code The code is as follows:

$oldimgs = $this->getimgsinarticle($oldarticledata['article_content']);
 $newimgs = $this->getimgsinarticle($data['articlecontent']);
 / /print_r($newimgs);
 $newimgs = empty($newimgs)?array():$newimgs;
 if($oldimgs!=false)
 {
 $diff = array_diff($ oldimgs,$newimgs);
 $diff = array_values($diff);
 if(!empty($diff))
 {
 for($i=0;$i {
 $this->delimg($diff[$i],ARTICLE_IMG_DIR);
 }
 }
 }

The method of deleting pictures is very simple as follows.

Copy code The code is as follows:

 public function delimg ($imgname,$dir)
 {
 @unlink($dir.'/'.$imgname);
 return true;
 }

This way I The purpose is achieved. When the user edits an article with pictures. If the picture is deleted, the corresponding picture will also be deleted from the website
The method of getting the name of the picture in the article can also be applied to the process of deleting the article. .

In the method of deleting pictures, you can use realpath(__FILE__) to add various "./""../" to $dir to give the picture directory relative to the directory of the website
For getting The regular expressions in the path in html are not very well written. It needs to be studied. I recently found a book on regular expressions. It is very good
Mastering Regular Expressions 3rd Edition by Jeffrey E.F. Friedl, translated by Yu Sheng (cheng)