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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /devtools/docs/user/view_source/index.rst | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | devtools/docs/user/view_source/index.rst | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/devtools/docs/user/view_source/index.rst b/devtools/docs/user/view_source/index.rst new file mode 100644 index 0000000000..12f7983dc8 --- /dev/null +++ b/devtools/docs/user/view_source/index.rst @@ -0,0 +1,90 @@ +=========== +View Source +=========== + +View Source lets you look at the HTML or XML source for the page you're viewing. To activate View Source: + +- context-click in the page and select *View Page Source* +- press :kbd:`Ctrl` + :kbd:`U` on Windows and Linux, or :kbd:`Cmd` + :kbd:`U` on macOS + +The command opens a new tab with the source for the current page. + +View Source features +******************** + +View Source has three additional features, which can be accessed from the context menu in the View Source tab: + +.. image:: view_source_context_menu.png + :class: center + +Go to Line + Scrolls to the specified line. If the number is higher than the lines in a file, you receive an error message. +Wrap Long Lines (toggle) + Wraps long lines to the width of the page. +Syntax Highlighting (toggle) + Applies syntax highlighting to the code.When syntax highlighting is on, View Source also highlights parsing errors in red. Hovering your mouse over errors displays a tooltip explaining the error. + +.. image:: view_source_error.png + :class: border + + +This feature is useful when you're looking for HTML errors. + +To access Go to Line from the keyboard, press :kbd:`Control` + :kbd:`Option` + :kbd:`L` on macOS, or :kbd:`Alt` + :kbd:`Shift` + :kbd:`L` on Windows or Linux. + + +Link to a line number +********************* + +It is possible to link to a particular line, by adding the #lineNNN anchor to the url the browser will jump to the NNN line. + +For example view-source:https://www.mozilla.org/#line100 + + +View Selection Source +********************* + +If you select part of a web page and context-click, you'll see a context menu item labeled "View Selection Source", that behaves just like "View Page Source", except you only see the source for the selection. + + +View MathML Source +****************** + +If you context-click while the mouse is over some `MathML <https://developer.mozilla.org/en-US/docs/Web/MathML>`_, you'll see a context menu item labeled "View MathML Source": click it to see the MathML source. + + +Limitations of View Source +************************** + +There are limitations to what View Source does for you that you need to be aware of. + +Error reporter ≠ validator +-------------------------- + +View Source only reports parsing errors, **not** HTML validity errors. For example, putting a `div <https://developer.mozilla.org/en-US/docs/Web/HTML/Element/div>`_ element as a child of a `ul <https://developer.mozilla.org/en-US/docs/Web/HTML/Element/ul>`_ element isn't a parse error, but it **is not** valid HTML. Therefore, this error will not be flagged in View Source. If you want to check that HTML is valid, you should use an HTML validator, such as `the one offered by W3C <https://validator.w3.org/>`_. + +Not all parse errors are reported +--------------------------------- + +Even though all the reported errors are parse errors according to the HTML specification, not all parse errors are reported by View Source. Among the errors that don't get reported: + + +- Bytes that are illegal according to the document's encoding aren't marked as errors. +- Forbidden characters aren't reported as errors. +- Errors related to the end-of-file aren't reported. +- Tree builder errors relating to text (as opposed to tags, comments, or doctypes) aren't reported. +- Parse errors related to ``xmlns`` attributes aren't reported. + + +XML syntax highlighting +*********************** + +View Source uses the HTML tokenizer when highlighting XML source. While the tokenizer has support for processing instructions when highlighting XML source, that's the only XML-specific capability provided. Because of this, doctypes that have an internal subset are not highlighted correctly, and entity references to custom entities are also not highlighted correctly. + +This mishighlighting can be seen by viewing the source of Firefox chrome files (such as XUL documents). However, this shouldn't be a problem in practice when viewing typical XML files. + + +See also +******** + +- `HTML5 Parser-Based View Source Syntax Highlighting <https://hsivonen.iki.fi/view-source/>`_ (Blog post) |