KTextTemplate::SafeString Class

class KTextTemplate::SafeString

A QString wrapper class for containing whether a string is safe or needs to be escaped. More...

Header:	`#include <KTextTemplate/SafeString>`
CMake:	`find_package(KF6 REQUIRED COMPONENTS TextTemplate)` `target_link_libraries(mytarget PRIVATE KF6::TextTemplate)`

List of all members, including inherited members

Public Types

class	NestedString
enum	Safety { IsSafe, IsNotSafe }

Public Functions

	SafeString()
	SafeString(const QString &str, KTextTemplate::SafeString::Safety safety = IsNotSafe)
	SafeString(const QString &str, bool safe)
KTextTemplate::SafeString::NestedString &	get()
const KTextTemplate::SafeString::NestedString &	get() const
bool	isSafe() const
bool	needsEscape() const
void	setNeedsEscape(bool needsEscape)
void	setSafety(KTextTemplate::SafeString::Safety safety)
QString	operator QString() const
QVariant	operator QVariant() const
KTextTemplate::SafeString	operator+(const KTextTemplate::SafeString &str)
KTextTemplate::SafeString	operator+(const QString &str)
KTextTemplate::SafeString &	operator+=(const KTextTemplate::SafeString &str)
KTextTemplate::SafeString &	operator+=(const QString &str)
KTextTemplate::SafeString &	operator=(const KTextTemplate::SafeString &str)
bool	operator==(const KTextTemplate::SafeString &other) const
bool	operator==(const QString &other) const

Detailed Description

This allows lazy escaping of strings. Otherwise a string may be escaped multiple times where it should only be escaped once.

The SafeString class itself provides information about whether a string is safe from further escaping through the isSafe method. The actual string content held by the SafeString instance is available through the get method. The get method returns a QString subclass which should be used like any other QString. The difference is that all methods on NestedString return a SafeString instead of a QString.

SafeString s("this & that", SafeString::IsSafe);
s.get().replace( "this", "these" ).toUpper();

qDebug() << s.get() << s.isSafe(); // outputs "these & that" false

Note that most operations on strings make the string unsafe. For example, while "K & R" is safe, using replace("m", "n") will result in "K &anp; R", which is unsafe. Likewise using upper() will return "K &AMP; R", which is unsafe. Because the SafeString can not determine whether a method call with particular arguments will change a SafeString from being safe to being unsafe, any operation which can possibly make the string unsafe does cause the string to become unsafe. It is then up to the caller to restore safe-ness if needed.

NestedString has overloads for SafeStrings whereever appropriate so that strings remain marked as safe where possible.

For example:

SafeString s1("this & that", SafeString::IsSafe);
s2 = s1;
s1.append( QString( " & the other" ) );
// s1 is now "this & that & the other" and is unsafe.

SafeString s3(" Wobl & Bob", SafeString::IsSafe);
s2.append(s3);
// Both s2 and s3 are safe, and append is a safe operation, so s2
// is still safe

The SafeString class has appropriate operator overloads to make it convenient to use in methods returning a QVariant, such as Filter::doFilter, or as a QString. Note that a raw QString is essentially the same as a SafeString which is marked as unsafe.

Member Type Documentation

enum SafeString::Safety

Possible safety states of a SafeString

Constant	Value	Description
`KTextTemplate::SafeString::IsSafe`	`0`	The string is safe and requires no further escaping
`KTextTemplate::SafeString::IsNotSafe`	`1`	The string is not safe. It will be escaped before being added to the output of rendering.

Member Function Documentation

SafeString::SafeString()

Constructs an empty SafeString.

SafeString::SafeString(const QString &str, KTextTemplate::SafeString::Safety safety = IsNotSafe)

Constructs a SafeString with the content str whose safety is given by safety.

SafeString::SafeString(const QString &str, bool safe)

Constructs a SafeString with the content str whose safety is given by safe.

KTextTemplate::SafeString::NestedString &SafeString::get()

Returns the String held by this SafeString

const KTextTemplate::SafeString::NestedString &SafeString::get() const

Returns the String held by this SafeString

bool SafeString::isSafe() const

Whether the string is safe.

bool SafeString::needsEscape() const

Whether the string needs to be escaped.

See also setNeedsEscape().

void SafeString::setNeedsEscape(bool needsEscape)

Set whether the string should be escaped.

See also needsEscape().

void SafeString::setSafety(KTextTemplate::SafeString::Safety safety)

Set whether the string is safe.

QString SafeString::operator QString() const

Convenience operator for treating a SafeString like a QString.

QVariant SafeString::operator QVariant() const

Convenience operator for storing a SafeString in a QVariant.

KTextTemplate::SafeString SafeString::operator+(const KTextTemplate::SafeString &str)

Returns a concatenation of this with str.

The result is safe if both this and str are safe.

KTextTemplate::SafeString SafeString::operator+(const QString &str)

Returns a concatenation of this with str.

The result is not safe because str is not safe.

KTextTemplate::SafeString &SafeString::operator+=(const KTextTemplate::SafeString &str)

Appends the content of str to this.

The result is safe if both this and str are safe.

KTextTemplate::SafeString &SafeString::operator+=(const QString &str)