PHP：致命错误：调用非对象上的成员函数
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PHP: Fatal error: Call to a member function on a non-object
提问by George Reith
Getting a very strange error here, I am writing a flatfile database class and this was all working fine until I refreshed and now I am constantly getting this message:
在这里遇到一个非常奇怪的错误，我正在编写一个平面文件数据库类，这一切正常，直到我刷新，现在我不断收到此消息：
Fatal error: Call to a member function name() on a non-object in /home/reithg/public_html/test/engine/class.database.phpon line 50
致命错误：在第50行的/home/reithg/public_html/test/engine/class.database.php 中的非对象上调用成员函数 name()
I am calling the Class as follows:
我按如下方式调用类：
<?php
ini_set('display_errors', '1');
require('engine/class.database.php');
$config = new Config("lessons", array('first', 'second', 'third', 'fourth'), "data/");
$db = new Database($config, true);
print("Querying DB for 'theta' no exclusions: <br />");
print_r($db->query('theta', NULL, NULL));
print("<p /> Querying DB for 'theta' in column 'second': <br />");
print_r($db->query('theta', 'second', NULL));
print("<p /> Querying DB for first two rows: <br />");
print_r($db->getRows(2));
print("<p /> Querying DB for last three rows: <br />");
print_r($db->getRows(3, true));
print("<p /> Cleaning data for safe DB input: <br />");
$testInput = array('escape|these||delimiters','and\these\slashes','and<?php
require('class.config.php');
require('class.column.php');
class Database {
private
$_config,
$_pointer;
public function __construct(Config $config) {
$this->_config = $config;
return true;
}
private function connect($method) {
if (!($this->_pointer = @fopen($this->_config->db(), $method)))
echo("Unable to connect to database");
}
private function disconnect() {
fclose($this->_pointer);
}
private function lock($method) {
if(flock($this->_pointer, $method))
return true;
return false;
}
private function unlock() {
flock($this->_pointer, LOCK_UN);
}
private function cleanInput($input) {
$data = array_map(array($this, 'escapeData'), $input);
$output = implode($this->_config->delimiter(), $data)."\r\n";
return $output;
}
private function escapeData($data)
{
$search = array('\', '"', "'", '\0', '\n', $this->_config->delimiter());
$replace = array('\\', '\"', "\'", '\0', '\n', '\'.$this->_config->delimiter());
$output = str_replace(array_unique($search), array_unique($replace), $data);
return $output;
}
private function formatRow($data) {
foreach($data as $key => $value) {
$row[$this->_config->columns($key, "position")->name()] = $value;
}
return $row;
}
public function dumpToArray() {
$arrayDump;
foreach(file($this->_config->db(), FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) as $row => $content)
$arrayDump[$row] = formatRow(explode($this->_config->delimiter(),$content));
return $arrayDump;
}
public function addRow(array $data) {
$this->connect('ab');
if($this->lock(LOCK_EX)) {
// fwrite($this->_pointer, $this->cleanInput($data));
echo($this->cleanInput($data));
$this->unlock();
$this->disconnect();
return true;
} else {
$this->disconnect();
return false;
}
}
public function query($value, $column = NULL, $limit = NULL) {
$this->connect('rb');
$results = array();
while ((is_null($limit) || (count($results) < $limit)) && !feof($this->_pointer)) {
$data = explode($this->_config->delimiter(), fgets($this->_pointer, 1024));
if(!is_null($column)) {
if ($data[$this->_config->columns($column, "string")->index()] == $value)
array_push($results, $this->formatRow($data));
} else {
if (in_array($value, $data))
array_push($results, $this->formatRow($data));
}
}
$this->disconnect();
switch (count($results)) {
case 0;
return false;
case 1;
return $results[0];
default;
return $results;
}
}
public function getRows($limit = 1, $reverse = false) {
$this->connect('rb');
$offset = 0;
$results = array();
if ($reverse) {
while(count($results) < $limit && fseek($this->_pointer, $offset, SEEK_END) >= 0) {
$char = fgetc($this->_pointer);
if($char == "\n" || $char == "\r"){
$offset --;
$data = explode($this->_config->delimiter(), fgets($this->_pointer, 1024));
array_push($results, $this->formatRow($data));
}
$offset--;
}
$results = array_reverse($results);
} else {
while ((($limit === NULL) || (count($results) < $limit)) && !feof($this->_pointer)) {
$data = explode($this->_config->delimiter(), fgets($this->_pointer, 1024));
array_push($results, $this->formatRow($data));
}
}
$this->disconnect();
return $results;
}
}
?>
these<?php
class Config {
private
$_db,
$_file,
$_columns = array(),
$_directory,
$_delimiter;
public function __construct($file, array $columns, $directory = NULL, $delimiter = "|") {
$this->_db = $directory.$file.".db";
$this->defineColumns($columns);
$this->_directory = $directory;
$this->_delimiter = $delimiter;
}
public function db() {
return $this->_db;
}
public function delimiter() {
return $this->_delimiter;
}
private function defineColumns($constants) {
for ($i=0;$i<count($constants);$i++) {
if(in_array($constants[$i], $this->_columns))
die("Column names must be unique");
$column = new Column($constants[$i], $i);
$this->_columns[$column->name()] = $column;
}
}
public function columns($index, $search = "string") {
switch ($search) {
case "string";
return $this->_columns[$index];
break;
case "position";
$keys = array_keys($this->_columns);
return $this->_columns[$keys[$index]];
break;
default;
return false;
}
}
}
?>
nulls',"don't, forget quotes");
print("input: ");
print_r($testInput);
echo("<br />output: ");
print($db->addRow($testInput));
?>
Here is my class.database.php
这是我的class.database.php
<?php
class Column {
const
ALL = "0",
STRING = "1",
NUMBER = "2",
INT = "3",
AUTO_INCREMENT = "4",
CURRENT_TIME = "5";
private
$_type = ALL,
$_name,
$_index,
$_maxChars = "256";
public function __construct($name, $index, $type = NULL, $maxChars = NULL) {
$this->_name = $name;
$this->_index = $index;
if(!is_null($type))
setDataType($type);
if(!is_null($maxChars))
setMaxChars($maxChars);
return $this;
}
public function setDataType($type) {
switch ($type) {
case ALL;
case STRING;
case NUMBER;
case INT;
case AUTO_INCREMENT;
case CURRENT_TIME;
$this->_type = $type;
break;
default;
return false;
}
}
public function auditData($data) {
switch ($this->_type) {
case ALL;
$output = $data;
break;
case STRING;
$output = (string) $data;
break;
case NUMBER;
$output = (float) $data;
break;
case INT;
$output = (int) $data;
break;
case AUTO_INCREMENT;
$output = (int) $data;
break;
case CURRENT_TIME;
$output = time();
break;
default;
return false;
}
return $output;
}
public function setMaxChars($maxChars) {
if(is_int($maxChars)) {
$this->_maxChars = $maxChars;
}
}
public function name() {
return $this->_name;
}
public function index() {
return $this->_index;
}
}
?>
class.config.php
类.config.php
print($this->_config->columns($key, "position"));
class.column.php
类.column.php
print($this->_config->columns($key, "position")->name());
I know it's a lot of code but I can't work out why this is happening all of a sudden, literally in one refresh without any change to code. Even if I backtrace to earlier versions that also worked this is happening.
我知道这是很多代码，但我无法弄清楚为什么会突然发生这种情况，实际上是在一次刷新中而不对代码进行任何更改。即使我回溯到同样有效的早期版本，这种情况也会发生。
When I attempt to do:
当我尝试做：
##代码##It returns:
它返回：
Catchable fatal error:Object of class Column could not be converted to string in /home/reithg/public_html/test/engine/class.database.php*on line 50*
可捕获的致命错误：第50 行*在/home/reithg/public_html/test/engine/class.database.php* 中无法将类 Column 的对象转换为字符串
Which shows that I am performing name()on a member of class Column which has a public method called name()
这表明我正在name()对 Column 类的一个成员进行表演，该成员有一个名为name()
When I do:
当我做：
##代码##it returns (one word per time as it is in a foreach loop);
它返回（每次一个单词，因为它在 foreach 循环中）；
first second third fourth first second third fourth
第一个第二个第三个第四个第二个第三个第四个
So it is clearly working 1 line before it.
所以它显然在它之前工作 1 行。
采纳答案by George Reith
The answer was due to hidden characters located in the lessons.dbfile.
答案是由于位于classes.db文件中的隐藏字符。
The error shown had nothing to do with this and I would like to thank everyone who took the time to give their two pence.
显示的错误与此无关，我要感谢所有花时间付出两便士的人。
回答by kraenhansen
I have two things for you:
我有两件事要给你：
- When you say: "I know it's a lot of code but I can't work out why this is happening all of a sudden, literally in one refresh without any change to code. Even if I backtrace to earlier versions that also worked this is happening." I would like to ask if you are programming on you PHP code through a browser? If so, sometimes the cache will mess with you, and I find it much easier to develop my PHP models through the PHP command-line interface. If this is not for you, maybe consider turning your browsers cache completely off when developing.
- I think the problem you are experiencing comes from syntax errors in the public function columns of your Config class. I think you have to read up on the syntax of switch-cases http://php.net/manual/en/control-structures.switch.phphere you will notice that you have used semicolons after case guards, where you should have used simply colons. Also there is no need to break; after you return, as your code will never reach this point anyway ...
- 当您说：“我知道有很多代码，但我无法弄清楚为什么会突然发生这种情况，实际上是在一次刷新中而不对代码进行任何更改。即使我回溯到同样有效的早期版本也是如此正在发生。” 我想问一下您是否正在通过浏览器对您的PHP代码进行编程？如果是这样，有时缓存会弄乱你，我发现通过 PHP 命令行界面开发我的 PHP 模型要容易得多。如果这不适合您，可以考虑在开发时完全关闭浏览器缓存。
- 我认为您遇到的问题来自 Config 类的公共函数列中的语法错误。我认为你必须阅读 switch-cases http://php.net/manual/en/control-structures.switch.php的语法，你会注意到你在 case guards 之后使用了分号，你应该有简单地使用冒号。也没有必要打破; 在您返回后，因为您的代码无论如何都不会到达这一点......
I hope this helps - good luck ...
我希望这会有所帮助 - 祝你好运......
