Searching in QFile which has source of webpage

roosaw

I have a source of the page which is downloaded by get method from QHttp and i wanna search a some phrase in it. How to do that?
Secondly, when i will search it i wanna go forward with a few chars then i wanna put what i got in double type and put it in a variable. How to do that?

I downloaded a page with something like that:
@file= new QFile("plik.xml", this);
file->open(QIODevice::ReadWrite);
http = new QHttp(this);
http->setHost("addressofpage.com");
http->get("/pathtopage.html", file);
@

giesbert

It depends :-)

If you know, it's xml, you can read it by SAX or DOM or other methods (see "QtXml":http://doc.qt.nokia.com/latest/qtxml.html or "QtXmlPatterns":http://doc.qt.nokia.com/latest/qtxmlpatterns.html ) and the work on the read data.

The other posibility is to read with "QTextStream":http://doc.qt.nokia.com/latest/qtextstream.html.

Examples to that can be found in the examples section of the documentation.

If it's not xml to parse, I would read into a QString and search/insert there

roosaw

First method (SAX, DOM) doesn't work. Example programs gives error (unknown char)
How to read to a QString?

QString str;
str << file;
?

CreMindES

Gerof is right I think, I would use QTextStream too...

giesbert

If you look at the given links ("QTextStream":http://doc.qt.nokia.com/latest/qtextstream.html#details ) there is a description, how to read a file to a QString.

you can also read using QFile directly. From the docu:

@
QFile file("in.txt");
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
return;

QTextStream in(&file);
while (!in.atEnd()) {
    QString line = in.readLine();
    process_line(line);
}

@

or

@
QFile file("in.txt");
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
return;

 while (!file.atEnd()) {
     QByteArray line = file.readLine();
     process_line(line);
 }

@

or

@
QFile file("in.txt");
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
return;

QTextStream in(&file);
QString str = in.readAll();

@

For more information on that, I propose a look at the Qt documentation (link in the top right corner, called DOC) :-)

giesbert

[quote author="roosaw" date="1293738563"]First method (SAX, DOM) doesn't work. Example programs gives error (unknown char)
...
?[/quote]

What type does your data has? is it XML? is it plain text?

roosaw

Can you tell me how to convert whole file into QTextStream?
I've done something like this (after closing file):

@QFile file("plik.xml");
if (file.open(QFile::ReadWrite)) {
QTextStream out(&plik);
out.readAll();
// out << "Result: " << qSetFieldWidth(10) << left << 3.14 << 2.7;
// writes "Result: 3.14 2.7 "
}
file.close();@

From documentation i know that it convert out to QString. Now how can i seek a phrase in there?

roosaw

[quote author="Gerolf" date="1293739383"]
[quote author="roosaw" date="1293738563"]First method (SAX, DOM) doesn't work. Example programs gives error (unknown char)
...
?[/quote]

What type does your data has? is it XML? is it plain text?[/quote]

I downloaded page with:
@ file= new QFile("plik.xml", this);
file->open(QIODevice::ReadWrite);
http = new QHttp(this);
http->setHost("addressofpage.com");
http->get("/pathtopage.html", file);@
but i can look at it in text editor so... i think it is a plain text.

giesbert

@
QFile file("in.txt");
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
return;

QTextStream in(&file);
QString str = in.readAll();
@

Then use QString functions

look at the docu, it is really good

something with find/search/indexOf...

BlackDante

[quote author="roosaw" date="1293739634"]Can you tell me how to convert whole file into QTextStream?
I've done something like this (after closing file):

@QFile file("plik.xml");
if (file.open(QFile::ReadWrite)) {
QTextStream out(&plik);
out.readAll();
// out << "Result: " << qSetFieldWidth(10) << left << 3.14 << 2.7;
// writes "Result: 3.14 2.7 "
}
file.close();@

From documentation i know that it convert out to QString. Now how can i seek a phrase in there?
[/quote]
You can first convert QFile into QString, example:
@QFile file(plik);
QString item;
file.open(QFile::ReadOnly);
char buff[255];
while (!file.atEnd())
{
file.readLine(buff, sizeof(buff));
item.append(buff);
}@
and QString you can convert to QTextStream
@QTextStream text = new QTextStream(item,QIODevice::ReadOnly);@

or you can even in QString find. You have function "indexOF":http://doc.qt.nokia.com/4.7/qstring.html#indexOf , who returns you position of looking word.

giesbert

First read the file into a QString, change the QString and write the string back to the file.

roosaw

[quote author="BlackDante" date="1293741181"]
You can first convert QFile into QString, example:
@QFile file(plik);
QString item;
file.open(QFile::ReadOnly);
char buff[255];
while (!file.atEnd())
{
file.readLine(buff, sizeof(buff));
item.append(buff);
}@[/quote]
Ok, it works :) I mean... compiling...
Now how can i search specific string in that QString (someting like item.seek("I/'m seeking this string");
Is there is something like this?
I found that:
http://doc.qt.nokia.com/latest/qstring.html#compare-5
but it compare only lenght of two strings...

giesbert

[quote author="Gerolf" date="1293741140"]@
QFile file("in.txt");
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
return;

QTextStream in(&file);
QString str = in.readAll();
@

Then use QString functions

look at the docu, it is really good

something with find/search/indexOf...[/quote]

If you read all posts, you perhaps find the solution :-)

"QString::indexOf":http://doc.qt.nokia.com/latest/qstring.html#indexOf

goetz

If you want to read the complete file into a string readAll() is your friend:

@
QFile file("mytextfile.txt");
if(!file.open(QIODevice::ReadOnly))
qFatal() << "File cannot be opened";

QTextStream ts(file);
QString fileContent = ts.readAll();
file.close();
@

If you read strings from a file it's always better to use QTextStream, as it does the proper decoding (UTF-8 etc.) for you.