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TheQWebElement class provides convenient access to DOM elements in aQWebFrame.More...
| Header: | #include <QWebElement> |
| Since: | Qt 4.6 |
| enum | StyleResolveStrategy { InlineStyle, CascadedStyle, ComputedStyle } |
| QWebElement() | |
| QWebElement(const QWebElement & other) | |
| ~QWebElement() | |
| void | addClass(const QString & name) |
| void | appendInside(const QString & markup) |
| void | appendInside(const QWebElement & element) |
| void | appendOutside(const QString & markup) |
| void | appendOutside(const QWebElement & element) |
| QString | attribute(const QString & name, const QString & defaultValue = QString()) const |
| QString | attributeNS(const QString & namespaceUri, const QString & name, const QString & defaultValue = QString()) const |
| QStringList | attributeNames(const QString & namespaceUri = QString()) const |
| QStringList | classes() const |
| QWebElement | clone() const |
| QWebElement | document() const |
| void | encloseContentsWith(const QWebElement & element) |
| void | encloseContentsWith(const QString & markup) |
| void | encloseWith(const QString & markup) |
| void | encloseWith(const QWebElement & element) |
| QVariant | evaluateJavaScript(const QString & scriptSource) |
| QWebElementCollection | findAll(const QString & selectorQuery) const |
| QWebElement | findFirst(const QString & selectorQuery) const |
| QWebElement | firstChild() const |
| QRect | geometry() const |
| bool | hasAttribute(const QString & name) const |
| bool | hasAttributeNS(const QString & namespaceUri, const QString & name) const |
| bool | hasAttributes() const |
| bool | hasClass(const QString & name) const |
| bool | hasFocus() const |
| bool | isNull() const |
| QWebElement | lastChild() const |
| QString | localName() const |
| QString | namespaceUri() const |
| QWebElement | nextSibling() const |
| QWebElement | parent() const |
| QString | prefix() const |
| void | prependInside(const QString & markup) |
| void | prependInside(const QWebElement & element) |
| void | prependOutside(const QString & markup) |
| void | prependOutside(const QWebElement & element) |
| QWebElement | previousSibling() const |
| void | removeAllChildren() |
| void | removeAttribute(const QString & name) |
| void | removeAttributeNS(const QString & namespaceUri, const QString & name) |
| void | removeClass(const QString & name) |
| void | removeFromDocument() |
| void | render(QPainter * painter) |
| void | render(QPainter * painter, const QRect & clip) |
| void | replace(const QString & markup) |
| void | replace(const QWebElement & element) |
| void | setAttribute(const QString & name, const QString & value) |
| void | setAttributeNS(const QString & namespaceUri, const QString & name, const QString & value) |
| void | setFocus() |
| void | setInnerXml(const QString & markup) |
| void | setOuterXml(const QString & markup) |
| void | setPlainText(const QString & text) |
| void | setStyleProperty(const QString & name, const QString & value) |
| QString | styleProperty(const QString & name, StyleResolveStrategy strategy) const |
| QString | tagName() const |
| QWebElement & | takeFromDocument() |
| QString | toInnerXml() const |
| QString | toOuterXml() const |
| QString | toPlainText() const |
| void | toggleClass(const QString & name) |
| QWebFrame * | webFrame() const |
| bool | operator!=(const QWebElement & o) const |
| QWebElement & | operator=(const QWebElement & other) |
| bool | operator==(const QWebElement & o) const |
TheQWebElement class provides convenient access to DOM elements in aQWebFrame.
AQWebElement object allows easy access to the document model, represented by a tree-like structure of DOM elements. The root of the tree is called the document element and can be accessed usingQWebFrame::documentElement().
Specific elements can be accessed usingfindAll() andfindFirst(). These elements are identified using CSS selectors. The code snippet below demonstrates the use offindAll().
QWebElement document= frame->documentElement();/* Assume the document has the following structure: <p class=intro> <span>Intro</span> <span>Snippets</span> </p> <p> <span>Content</span> <span>Here</span> </p> */QWebElementCollection allSpans= document.findAll("span");QWebElementCollection introSpans= document.findAll("p.intro span");
The first list contains allspan elements in the document. The second list containsspan elements that are children ofp, classified withintro.
UsingfindFirst() is more efficient than callingfindAll(), and extracting the first element only in the list returned.
Alternatively you can traverse the document manually usingfirstChild() andnextSibling():
frame->setHtml("<html><body><p>First Paragraph</p><p>Second Paragraph</p></body></html>");QWebElement doc= frame->documentElement();QWebElement body= doc.firstChild();QWebElement firstParagraph= body.firstChild();QWebElement secondParagraph= firstParagraph.nextSibling();
Individual elements can be inspected or changed using methods such asattribute() orsetAttribute(). For examle, to capture the user's input in a text field for later use (auto-completion), a browser could do something like this:
QWebElement firstTextInput= document.findFirst("input[type=text]");QString storedText= firstTextInput.attribute("value");
When the same page is later revisited, the browser can fill in the text field automatically by modifying the value attribute of the input element:
QWebElement firstTextInput= document.findFirst("input[type=text]"); textInput.setAttribute("value", storedText);
Another use case is to emulate a click event on an element. The following code snippet demonstrates how to call the JavaScript DOM method click() of a submit button:
QWebElement document= frame->documentElement();/* Assume that the document has the following structure: <form name="myform" action="submit_form.asp" method="get"> <input type="text" name="myfield"> <input type="submit" value="Submit"> </form> */QWebElement button= document.findFirst("input[type=submit]"); button.evaluateJavaScript("this.click()");
The underlying content ofQWebElement is explicitly shared. Creating a copy of aQWebElement does not create a copy of the content. Instead, both instances point to the same element.
The contents of child elements can be converted to plain text withtoPlainText(); to XHTML usingtoInnerXml(). To include the element's tag in the output, usetoOuterXml().
It is possible to replace the contents of child elements usingsetPlainText() andsetInnerXml(). To replace the element itself and its contents, usesetOuterXml().
TheDOM Traversal Example shows one way to traverse documents in a running example.
TheSimple Selector Example can be used to experiment with the searching features of this class and provides sample code you can start working with.
This enum describes howQWebElement'sstyleProperty resolves the given property name.
| Constant | Value | Description |
|---|---|---|
QWebElement::InlineStyle | 0 | Return the property value as it is defined in the element, without respecting style inheritance and other CSS rules. |
QWebElement::CascadedStyle | 1 | The property's value is determined using the inheritance and importance rules defined in the document's stylesheet. |
QWebElement::ComputedStyle | 2 | The property's value is the absolute value of the style property resolved from the environment. |
Constructs a null web element.
Constructs a copy ofother.
Destroys the element. However, the underlying DOM element is not destroyed.
Adds the specified class with the givenname to the element.
Appends the result of parsingmarkup as the element's last child.
Calling this function on a null element does nothing.
See alsoprependInside(),prependOutside(), andappendOutside().
Appends the givenelement as the element's last child.
Ifelement is the child of another element, it is re-parented to this element. Ifelement is a child of this element, then its position in the list of children is changed.
Calling this function on a null element does nothing.
See alsoprependInside(),prependOutside(), andappendOutside().
Inserts the result of parsingmarkup after this element.
Calling this function on a null element does nothing.
See alsoappendInside(),prependInside(), andprependOutside().
Inserts the givenelement after this element.
Ifelement is the child of another element, it is re-parented to the parent of this element.
Calling this function on a null element does nothing.
See alsoappendInside(),prependInside(), andprependOutside().
Returns the attribute with the givenname. If the attribute does not exist,defaultValue is returned.
See alsosetAttribute(),setAttributeNS(), andattributeNS().
Returns the attribute with the givenname innamespaceUri. If the attribute does not exist,defaultValue is returned.
See alsosetAttributeNS(),setAttribute(), andattribute().
Return the list of attributes for the namespace given asnamespaceUri.
See alsoattribute() andsetAttribute().
Returns the list of classes of this element.
Returns a clone of this element.
The clone may be inserted at any point in the document.
See alsoappendInside(),prependInside(),prependOutside(), andappendOutside().
Returns the document which this element belongs to.
Encloses the contents of this element withelement. This element becomes the child of the deepest descendant withinelement.
### illustration
See alsoencloseWith().
Encloses the contents of this element with the result of parsingmarkup. This element becomes the child of the deepest descendant withinmarkup.
See alsoencloseWith().
Encloses this element with the result of parsingmarkup. This element becomes the child of the deepest descendant withinmarkup.
See alsoreplace().
Encloses this element withelement. This element becomes the child of the deepest descendant withinelement.
See alsoreplace().
ExecutesscriptSource with this element asthis object.
Returns a new list of child elements matching the given CSS selectorselectorQuery. If there are no matching elements, an empty list is returned.
Standard CSS2 selector syntax is used for the query.
Note:This search is performed recursively.
See alsofindFirst().
Returns the first child element that matches the given CSS selectorselectorQuery.
Standard CSS2 selector syntax is used for the query.
Note:This search is performed recursively.
See alsofindAll().
Returns the element's first child.
See alsolastChild(),previousSibling(), andnextSibling().
Returns the geometry of this element, relative to its containing frame.
See alsotagName().
Returns true if this element has an attribute with the givenname; otherwise returns false.
See alsoattribute() andsetAttribute().
Returns true if this element has an attribute with the givenname, innamespaceUri; otherwise returns false.
See alsoattributeNS() andsetAttributeNS().
Returns true if the element has any attributes defined; otherwise returns false;
See alsoattribute() andsetAttribute().
Returns true if this element has a class with the givenname; otherwise returns false.
Returns true if the element has keyboard input focus; otherwise, returns false
See alsosetFocus().
Returns true if the element is a null element; otherwise returns false.
Returns the element's last child.
See alsofirstChild(),previousSibling(), andnextSibling().
Returns the local name of the element. If the element does not use namespaces, an empty string is returned.
Returns the namespace URI of this element. If the element has no namespace URI, an empty string is returned.
Returns the element's next sibling.
See alsofirstChild(),previousSibling(), andlastChild().
Returns the parent element of this elemen. If this element is the root document element, a null element is returned.
Returns the namespace prefix of the element. If the element has no namespace prefix, empty string is returned.
Prepends the result of parsingmarkup as the element's first child.
Calling this function on a null element does nothing.
See alsoappendInside(),prependOutside(), andappendOutside().
Prependselement as the element's first child.
Ifelement is the child of another element, it is re-parented to this element. Ifelement is a child of this element, then its position in the list of children is changed.
Calling this function on a null element does nothing.
See alsoappendInside(),prependOutside(), andappendOutside().
Inserts the result of parsingmarkup before this element.
Calling this function on a null element does nothing.
See alsoappendInside(),prependInside(), andappendOutside().
Inserts the givenelement before this element.
Ifelement is the child of another element, it is re-parented to the parent of this element.
Calling this function on a null element does nothing.
See alsoappendInside(),prependInside(), andappendOutside().
Returns the element's previous sibling.
See alsofirstChild(),nextSibling(), andlastChild().
Removes all children from this element.
See alsoremoveFromDocument() andtakeFromDocument().
Removes the attribute with the givenname from this element.
See alsoattribute(),setAttribute(), andhasAttribute().
Removes the attribute with the givenname, innamespaceUri, from this element.
See alsoattributeNS(),setAttributeNS(), andhasAttributeNS().
Removes the specified class with the givenname from the element.
Removes this element from the document and makes it a null element.
See alsoremoveAllChildren() andtakeFromDocument().
Render the element intopainter .
Render the element intopainter clipping toclip.
Replaces this element with the result of parsingmarkup.
This method will not replace the <html>, <head> or <body> elements.
See alsoencloseWith().
Replaces this element withelement.
This method will not replace the <html>, <head> or <body> elements.
See alsoencloseWith().
Adds an attribute with the givenname andvalue. If an attribute with the same name exists, its value is replaced byvalue.
See alsoattribute(),attributeNS(), andsetAttributeNS().
Adds an attribute with the givenname innamespaceUri withvalue. If an attribute with the same name exists, its value is replaced byvalue.
See alsoattributeNS(),attribute(), andsetAttribute().
Gives keyboard input focus to this element
See alsohasFocus().
Replaces the contents of this element withmarkup. The string may contain HTML or XML tags, which is parsed and formatted before insertion into the document.
Note:This is currently implemented for (X)HTML elements only.
See alsotoInnerXml(),toOuterXml(), andsetOuterXml().
Replaces the contents of this element as well as its own tag withmarkup. The string may contain HTML or XML tags, which is parsed and formatted before insertion into the document.
Note:This is currently only implemented for (X)HTML elements.
See alsotoOuterXml(),toInnerXml(), andsetInnerXml().
Replaces the existing content of this element withtext.
This is equivalent to setting the HTML innerText property.
See alsotoPlainText().
Sets the value of the inline style with the givenname tovalue.
Setting a value, does not necessarily mean that it will become the applied value, due to the fact that the style property's value might have been set earlier with a higher priority in external or embedded style declarations.
In order to ensure that the value will be applied, you may have to append "!important" to the value.
See alsostyleProperty().
Returns the value of the style with the givenname using the specifiedstrategy. If a style withname does not exist, an empty string is returned.
In CSS, the cascading part depends on which CSS rule has priority and is thus applied. Generally, the last defined rule has priority. Thus, an inline style rule has priority over an embedded block style rule, which in return has priority over an external style rule.
If the "!important" declaration is set on one of those, the declaration receives highest priority, unless other declarations also use the "!important" declaration. Then, the last "!important" declaration takes predecence.
See alsosetStyleProperty().
Returns the tag name of this element.
See alsogeometry().
Removes this element from the document and returns a reference to it.
The element is still valid after removal, and can be inserted into other parts of the document.
See alsoremoveAllChildren() andremoveFromDocument().
Returns the XML content between the element's start and end tags.
Note:This is currently implemented for (X)HTML elements only.
Note:The format of the markup returned will obey the namespace of the document containing the element. This means the return value will obey XML formatting rules, such as self-closing tags, only if the document is 'text/xhtml+xml'.
See alsosetInnerXml(),setOuterXml(), andtoOuterXml().
Returns this element converted to XML, including the start and the end tags as well as its attributes.
Note:This is currently implemented for (X)HTML elements only.
Note:The format of the markup returned will obey the namespace of the document containing the element. This means the return value will obey XML formatting rules, such as self-closing tags, only if the document is 'text/xhtml+xml'.
See alsosetOuterXml(),setInnerXml(), andtoInnerXml().
Returns the text between the start and the end tag of this element.
This is equivalent to reading the HTML innerText property.
See alsosetPlainText().
Adds the specified class with the givenname if it is not present. If the class is already present, it will be removed.
Returns the web frame which this element is a part of. If the element is a null element, null is returned.
Returns true if this element points to a different underlying DOM object thano; otherwise returns false.
Assignsother to this element and returns a reference to this element.
Returns true if this element points to the same underlying DOM object aso; otherwise returns false.
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