godoc: add codewalk support

R=adg, gri
CC=golang-dev, r
https://golang.org/cl/1008042
This commit is contained in:
Russ Cox 2010-04-26 22:35:12 -07:00
parent 72d9322032
commit 2a591bdf8a
10 changed files with 1244 additions and 3 deletions

234
doc/codewalk/codewalk.css Normal file
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/*
Copyright 2010 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file.
*/
#codewalk-main {
text-align: left;
width: 100%;
overflow: auto;
}
#code-display {
border: 0;
width: 100%;
}
.setting {
font-size: 8pt;
color: #888888;
padding: 5px;
}
.hotkey {
text-decoration: underline;
}
/* Style for Comments (the left-hand column) */
#comment-column {
margin: 0pt;
width: 30%;
}
#comment-column.right {
float: right;
}
#comment-column.left {
float: left;
}
#comment-area {
overflow-x: hidden;
overflow-y: auto;
}
.comment {
cursor: pointer;
font-size: 16px;
border: 2px solid #ba9836;
margin-bottom: 10px;
margin-right: 10px; /* yes, for both .left and .right */
}
.comment:last-child {
margin-bottom: 0px;
}
.right .comment {
margin-left: 10px;
}
.right .comment.first {
}
.right .comment.last {
}
.left .comment.first {
}
.left .comment.last {
}
.comment.selected {
border-color: #99b2cb;
}
.right .comment.selected {
border-left-width: 12px;
margin-left: 0px;
}
.left .comment.selected {
border-right-width: 12px;
margin-right: 0px;
}
.comment-link {
display: none;
}
.comment-title {
font-size: small;
font-weight: bold;
background-color: #fffff0;
padding-right: 10px;
padding-left: 10px;
padding-top: 5px;
padding-bottom: 5px;
}
.right .comment-title {
}
.left .comment-title {
}
.comment.selected .comment-title {
background-color: #f8f8ff;
}
.comment-text {
overflow: auto;
padding-left: 10px;
padding-right: 10px;
padding-top: 10px;
padding-bottom: 5px;
font-size: small;
line-height: 1.3em;
}
.comment-text p {
margin-top: 0em;
margin-bottom: 0.5em;
}
.comment-text p:last-child {
margin-bottom: 0em;
}
.file-name {
font-size: x-small;
padding-top: 0px;
padding-bottom: 5px;
}
.hidden-filepaths .file-name {
display: none;
}
.path-dir {
color: #555;
}
.path-file {
color: #555;
}
/* Style for Code (the right-hand column) */
/* Wrapper for the code column to make widths get calculated correctly */
#code-column {
display: block;
position: relative;
margin: 0pt;
width: 70%;
}
#code-column.left {
float: left;
}
#code-column.right {
float: right;
}
#code-area {
background-color: #f8f8ff;
border: 2px solid #99b2cb;
padding: 5px;
}
.left #code-area {
margin-right: -1px;
}
.right #code-area {
margin-left: -1px;
}
#code-header {
margin-bottom: 5px;
}
#code {
background-color: white;
}
code {
font-size: 100%;
}
.codewalkhighlight {
font-weight: bold;
background-color: #f8f8ff;
}
#code-display {
margin-top: 0px;
margin-bottom: 0px;
}
#sizer {
position: absolute;
cursor: col-resize;
left: 0px;
top: 0px;
width: 8px;
}
/* Style for options (bottom strip) */
#code-options {
display: none;
}
#code-options > span {
padding-right: 20px;
}
#code-options .selected {
border-bottom: 1px dotted;
}
#comment-options {
text-align: center;
}
div#content {
padding-bottom: 0em;
}

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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
/**
* A class to hold information about the Codewalk Viewer.
* @param {jQuery} context The top element in whose context the viewer should
* operate. It will not touch any elements above this one.
* @constructor
*/
var CodewalkViewer = function(context) {
this.context = context;
/**
* The div that contains all of the comments and their controls.
*/
this.commentColumn = this.context.find('#comment-column');
/**
* The div that contains the comments proper.
*/
this.commentArea = this.context.find('#comment-area');
/**
* The div that wraps the iframe with the code, as well as the drop down menu
* listing the different files.
* @type {jQuery}
*/
this.codeColumn = this.context.find('#code-column');
/**
* The div that contains the code but excludes the options strip.
* @type {jQuery}
*/
this.codeArea = this.context.find('#code-area');
/**
* The iframe that holds the code (from Sourcerer).
* @type {jQuery}
*/
this.codeDisplay = this.context.find('#code-display');
/**
* The overlaid div used as a grab handle for sizing the code/comment panes.
* @type {jQuery}
*/
this.sizer = this.context.find('#sizer');
/**
* The full-screen overlay that ensures we don't lose track of the mouse
* while dragging.
* @type {jQuery}
*/
this.overlay = this.context.find('#overlay');
/**
* The hidden input field that we use to hold the focus so that we can detect
* shortcut keypresses.
* @type {jQuery}
*/
this.shortcutInput = this.context.find('#shortcut-input');
/**
* The last comment that was selected.
* @type {jQuery}
*/
this.lastSelected = null;
};
/**
* Minimum width of the comments or code pane, in pixels.
* @type {number}
*/
CodewalkViewer.MIN_PANE_WIDTH = 200;
/**
* Navigate the code iframe to the given url and update the code popout link.
* @param {string} url The target URL.
* @param {Object} opt_window Window dependency injection for testing only.
*/
CodewalkViewer.prototype.navigateToCode = function(url, opt_window) {
if (!opt_window) opt_window = window;
// Each iframe is represented by two distinct objects in the DOM: an iframe
// object and a window object. These do not expose the same capabilities.
// Here we need to get the window representation to get the location member,
// so we access it directly through window[] since jQuery returns the iframe
// representation.
// We replace location rather than set so as not to create a history for code
// navigation.
opt_window['code-display'].location.replace(url);
var k = url.indexOf('&');
if (k != -1) url = url.slice(0, k);
k = url.indexOf('fileprint=');
if (k != -1) url = url.slice(k+10, url.length);
this.context.find('#code-popout-link').attr('href', url);
};
/**
* Selects the first comment from the list and forces a refresh of the code
* view.
*/
CodewalkViewer.prototype.selectFirstComment = function() {
// TODO(rsc): handle case where there are no comments
var firstSourcererLink = this.context.find('.comment:first');
this.changeSelectedComment(firstSourcererLink);
};
/**
* Sets the target on all links nested inside comments to be _blank.
*/
CodewalkViewer.prototype.targetCommentLinksAtBlank = function() {
this.context.find('.comment a[href], #description a[href]').each(function() {
if (!this.target) this.target = '_blank';
});
};
/**
* Installs event handlers for all the events we care about.
*/
CodewalkViewer.prototype.installEventHandlers = function() {
var self = this;
this.context.find('.comment')
.click(function(event) {
if (jQuery(event.target).is('a[href]')) return true;
self.changeSelectedComment(jQuery(this));
return false;
});
this.context.find('#code-selector')
.change(function() {self.navigateToCode(jQuery(this).val());});
this.context.find('#description-table .quote-feet.setting')
.click(function() {self.toggleDescription(jQuery(this)); return false;});
this.sizer
.mousedown(function(ev) {self.startSizerDrag(ev); return false;});
this.overlay
.mouseup(function(ev) {self.endSizerDrag(ev); return false;})
.mousemove(function(ev) {self.handleSizerDrag(ev); return false;});
this.context.find('#prev-comment')
.click(function() {
self.changeSelectedComment(self.lastSelected.prev()); return false;
});
this.context.find('#next-comment')
.click(function() {
self.changeSelectedComment(self.lastSelected.next()); return false;
});
// Workaround for Firefox 2 and 3, which steal focus from the main document
// whenever the iframe content is (re)loaded. The input field is not shown,
// but is a way for us to bring focus back to a place where we can detect
// keypresses.
this.context.find('#code-display')
.load(function(ev) {self.shortcutInput.focus();});
jQuery(document).keypress(function(ev) {
switch(ev.which) {
case 110: // 'n'
self.changeSelectedComment(self.lastSelected.next());
return false;
case 112: // 'p'
self.changeSelectedComment(self.lastSelected.prev());
return false;
default: // ignore
}
});
window.onresize = function() {self.updateHeight();};
};
/**
* Starts dragging the pane sizer.
* @param {Object} ev The mousedown event that started us dragging.
*/
CodewalkViewer.prototype.startSizerDrag = function(ev) {
this.initialCodeWidth = this.codeColumn.width();
this.initialCommentsWidth = this.commentColumn.width();
this.initialMouseX = ev.pageX;
this.overlay.show();
};
/**
* Handles dragging the pane sizer.
* @param {Object} ev The mousemove event updating dragging position.
*/
CodewalkViewer.prototype.handleSizerDrag = function(ev) {
var delta = ev.pageX - this.initialMouseX;
if (this.codeColumn.is('.right')) delta = -delta;
var proposedCodeWidth = this.initialCodeWidth + delta;
var proposedCommentWidth = this.initialCommentsWidth - delta;
var mw = CodewalkViewer.MIN_PANE_WIDTH;
if (proposedCodeWidth < mw) delta = mw - this.initialCodeWidth;
if (proposedCommentWidth < mw) delta = this.initialCommentsWidth - mw;
proposedCodeWidth = this.initialCodeWidth + delta;
proposedCommentWidth = this.initialCommentsWidth - delta;
// If window is too small, don't even try to resize.
if (proposedCodeWidth < mw || proposedCommentWidth < mw) return;
this.codeColumn.width(proposedCodeWidth);
this.commentColumn.width(proposedCommentWidth);
this.options.codeWidth = parseInt(
this.codeColumn.width() /
(this.codeColumn.width() + this.commentColumn.width()) * 100);
this.context.find('#code-column-width').text(this.options.codeWidth + '%');
};
/**
* Ends dragging the pane sizer.
* @param {Object} ev The mouseup event that caused us to stop dragging.
*/
CodewalkViewer.prototype.endSizerDrag = function(ev) {
this.overlay.hide();
this.updateHeight();
};
/**
* Toggles the Codewalk description between being shown and hidden.
* @param {jQuery} target The target that was clicked to trigger this function.
*/
CodewalkViewer.prototype.toggleDescription = function(target) {
var description = this.context.find('#description');
description.toggle();
target.find('span').text(description.is(':hidden') ? 'show' : 'hide');
this.updateHeight();
};
/**
* Changes the side of the window on which the code is shown and saves the
* setting in a cookie.
* @param {string?} codeSide The side on which the code should be, either
* 'left' or 'right'.
*/
CodewalkViewer.prototype.changeCodeSide = function(codeSide) {
var commentSide = codeSide == 'left' ? 'right' : 'left';
this.context.find('#set-code-' + codeSide).addClass('selected');
this.context.find('#set-code-' + commentSide).removeClass('selected');
// Remove previous side class and add new one.
this.codeColumn.addClass(codeSide).removeClass(commentSide);
this.commentColumn.addClass(commentSide).removeClass(codeSide);
this.sizer.css(codeSide, 'auto').css(commentSide, 0);
this.options.codeSide = codeSide;
};
/**
* Adds selected class to newly selected comment, removes selected style from
* previously selected comment, changes drop down options so that the correct
* file is selected, and updates the code popout link.
* @param {jQuery} target The target that was clicked to trigger this function.
*/
CodewalkViewer.prototype.changeSelectedComment = function(target) {
var currentFile = target.find('.comment-link').attr('href');
if (!currentFile) return;
if (!(this.lastSelected && this.lastSelected.get(0) === target.get(0))) {
if (this.lastSelected) this.lastSelected.removeClass('selected');
target.addClass('selected');
this.lastSelected = target;
var targetTop = target.position().top;
var parentTop = target.parent().position().top;
if (targetTop + target.height() > parentTop + target.parent().height() ||
targetTop < parentTop) {
var delta = targetTop - parentTop;
target.parent().animate(
{'scrollTop': target.parent().scrollTop() + delta},
Math.max(delta / 2, 200), 'swing');
}
var fname = currentFile.match(/(?:select=|fileprint=)\/[^&]+/)[0];
fname = fname.slice(fname.indexOf('=')+2, fname.length);
this.context.find('#code-selector').val(fname);
this.context.find('#prev-comment').toggleClass(
'disabled', !target.prev().length);
this.context.find('#next-comment').toggleClass(
'disabled', !target.next().length);
}
// Force original file even if user hasn't changed comments since they may
// have nagivated away from it within the iframe without us knowing.
this.navigateToCode(currentFile);
};
/**
* Updates the viewer by changing the height of the comments and code so that
* they fit within the height of the window. The function is typically called
* after the user changes the window size.
*/
CodewalkViewer.prototype.updateHeight = function() {
var windowHeight = jQuery(window).height() - 5 // GOK
var areaHeight = windowHeight - this.codeArea.offset().top
var footerHeight = this.context.find('#footer').outerHeight(true)
this.commentArea.height(areaHeight - footerHeight - this.context.find('#comment-options').outerHeight(true))
var codeHeight = areaHeight - footerHeight - 15 // GOK
this.codeArea.height(codeHeight)
this.codeDisplay.height(codeHeight - this.codeDisplay.offset().top + this.codeArea.offset().top);
this.sizer.height(codeHeight);
};
jQuery(document).ready(function() {
var viewer = new CodewalkViewer(jQuery());
viewer.selectFirstComment();
viewer.targetCommentLinksAtBlank();
viewer.installEventHandlers();
viewer.updateHeight();
});

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<codewalk title="How to Write a Codewalk">
<step title="Introduction" src="doc/codewalk/codewalk.xml">
A codewalk is a guided tour through a piece of code.
It consists of a sequence of steps, each typically explaining
a highlighted section of code.
<br/><br/>
The <a href="/cmd/godoc">godoc</a> web server translates
an XML file like the one in the main window pane into the HTML
page that you're viewing now.
<br/><br/>
The codewalk with URL path <code>/doc/codewalk/</code><i>name</i>
is loaded from the input file <code>$GOROOT/doc/codewalk/</code><i>name</i><code>.xml</code>.
<br/><br/>
This codewalk explains how to write a codewalk by examining
its own source code,
<code><a href="/doc/codewalk/codewalk.xml">$GOROOT/doc/codewalk/codewalk.xml</a></code>,
shown in the main window pane to the left.
</step>
<step title="Title" src="doc/codewalk/codewalk.xml:/title=/">
The codewalk input file is an XML file containing a single
<code>&lt;codewalk&gt;</code> element.
That element's <code>title</code> attribute gives the title
that is used both on the codewalk page and in the codewalk list.
</step>
<step title="Steps" src="doc/codewalk/codewalk.xml:/&lt;step/,/step&gt;/">
Each step in the codewalk is a <code>&lt;step&gt;</code> element
nested inside the main <code>&lt;codewalk&gt;</code>.
The step element's <code>title</code> attribute gives the step's title,
which is shown in a shaded bar above the main step text.
The element's <code>src</code> attribute specifies the source
code to show in the main window pane and, optionally, a range of
lines to highlight.
<br/><br/>
The first step in this codewalk does not highlight any lines:
its <code>src</code> is just a file name.
</step>
<step title="Specifiying a source line" src='doc/codewalk/codewalk.xml:/title="Title"/'>
The most complex part of the codewalk specification is
saying what lines to highlight.
Instead of ordinary line numbers,
the codewalk uses an address syntax that makes it possible
to describe the match by its content.
As the file gets edited, this descriptive address has a better
chance to continue to refer to the right section of the file.
<br/><br/>
To specify a source line, use a <code>src</code> attribute of the form
<i>filename</i><code>:</code><i>address</i>,
where <i>address</i> is an address in the syntax used by the text editors <i>sam</i> and <i>acme</i>.
<br/><br/>
The simplest address is a single regular expression.
The highlighted line in the main window pane shows that the
address for the &ldquo;Title&rdquo; step was <code>/title=/</code>,
which matches the first instance of that <a href="/pkg/regexp">regular expression</a> (<code>title=</code>) in the file.
</step>
<step title="Specifying a source range" src='doc/codewalk/codewalk.xml:/title="Steps"/'>
To highlight a range of source lines, the simplest address to use is
a pair of regular expressions
<code>/</code><i>regexp1</i><code>/,/</code><i>regexp2</i><code>/</code>.
The highlight begins with the line containing the first match for <i>regexp1</i>
and ends with the line containing the first match for <i>regexp2</i>
after the end of the match for <i>regexp1</i>.
Ignoring the HTML quoting,
The line containing the first match for <i>regexp1</i> will be the first one highlighted,
and the line containing the first match for <i>regexp2</i>.
<br/><br/>
The address <code>/&lt;step/,/step&gt;/</code> looks for the first instance of
<code>&lt;step</code> in the file, and then starting after that point,
looks for the first instance of <code>step&gt;</code>.
(Click on the &ldquo;Steps&rdquo; step above to see the highlight in action.)
Note that the <code>&lt;</code> and <code>&gt;</code> had to be written
using XML escapes in order to be valid XML.
</step>
<step title="Advanced addressing" src="doc/codewalk/codewalk.xml:/Advanced/,/step&gt;/">
The <code>/</code><i>regexp</i><code>/</code>
and <code>/</code><i>regexp1</i><code>/,/</code><i>regexp2</i><code>/</code>
forms suffice for most highlighting.
<br/><br/>
The full address syntax is summarized in this table
(an excerpt of Table II from
<a href="http://plan9.bell-labs.com/sys/doc/sam/sam.html">The text editor <code>sam</code></a>):
<br/><br/>
<table>
<tr><td colspan="2"><b>Simple addresses</b></td></tr>
<tr><td><code>#</code><i>n</i></td>
<td>The empty string after character <i>n</i></td></tr>
<tr><td><i>n</i></td>
<td>Line <i>n</i></td></tr>
<tr><td><code>/</code><i>regexp</i><code>/</code></td>
<td>The first following match of the regular expression</td></tr>
<!-- not supported (yet?)
<tr><td><code>/</code><i>regexp</i><code>/</code></td>
<td>The first previous match of the regular expression</td></tr>
-->
<tr><td><code>$</code></td>
<td>The null string at the end of the file</td></tr>
<tr><td colspan="2"><b>Compound addresses</b></td></tr>
<tr><td><i>a1</i><code>+</code><i>a2</i></td>
<td>The address <i>a2</i> evaluated starting at the right of <i>a1</i></td></tr>
<tr><td><i>a1</i><code>-</code><i>a2</i></td>
<td>The address <i>a2</i> evaluated in the reverse direction starting at the left of <i>a1</i></td></tr>
<tr><td><i>a1</i><code>,</code><i>a2</i></td>
<td>From the left of <i>a1</i> to the right of <i>a2</i> (default <code>0,$</code>).</td></tr>
</table>
</step>
</codewalk>

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@ -45,6 +45,7 @@ span.alert {
body {
font: 13px Helvetica, Arial, sans-serif;
margin-bottom: 0px;
}
h1 {
@ -102,6 +103,7 @@ div#content {
margin-left: 20%;
padding: 0 1em 2em 1em;
margin-top: 0px;
margin-bottom: 0px;
/*
border-left: 2px solid #e5ecf9;
border-right: 2px solid #e5ecf9;
@ -156,12 +158,16 @@ div#linkList li.navhead {
}
#footer {
margin: 2em;
margin: 2em 0 0 0;
text-align: center;
color: #555;
font-size: small;
}
#footer p {
margin: 0px;
}
#footer a {
color: #555;
}

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<!--
Copyright 2010 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file.
-->
<script src="http://www.google.com/jsapi"></script>
<script>google.load("jquery", "1.3.2");</script>
<style type='text/css'>@import "/doc/codewalk/codewalk.css";</style>
<script type="text/javascript" src="/doc/codewalk/codewalk.js"></script>
<div id="codewalk-main">
<div class="left" id="code-column">
<div id='sizer'></div>
<div id="code-area">
<div id="code-header" align="center">
<a id="code-popout-link" href="" target="_blank">
<img title="View code in new window" alt="Pop Out Code" src="popout.png" style="display: block; float: right;"/>
</a>
<select id="code-selector">
{.repeated section File}
<option value="/doc/codewalk/?fileprint=/{@|html-esc}">{@|html-esc}</option>
{.end}
</select>
</div>
<div id="code">
<iframe class="code-display" name="code-display" id="code-display"></iframe>
</div>
</div>
<div id="code-options" class="setting">
<span>code on <a id="set-code-left" class="selected" href="#">left</a> &bull; <a id="set-code-right" href="#">right</a></span>
<span>code width <span id="code-column-width">70%</span></span>
<span>filepaths <a id="show-filepaths" class="selected" href="#">shown</a> &bull; <a id="hide-filepaths" href="#">hidden</a></span>
</div>
</div>
<div class="right" id="comment-column">
<div id="comment-area">
{.repeated section Step}
<div class="comment first last">
<a class="comment-link" href="/doc/codewalk/?fileprint=/{File|html-esc}&lo={Lo|html-esc}&hi={Hi|html-esc}#mark" target="code-display"></a>
<div class="comment-title">{Title|html-esc}</div>
<div class="comment-text">
{.section Err}
ERROR LOADING FILE: {Err|html-esc}<br/><br/>
{.end}
{XML}
</div>
<div class="comment-text file-name"><span class="path-file">{@|html-esc}</span></div>
</div>
{.end}
</div>
<div id="comment-options" class="setting">
<a id="prev-comment" href="#"><span class="hotkey">p</span>revious step</a>
&bull;
<a id="next-comment" href="#"><span class="hotkey">n</span>ext step</a>
</div>
</div>
</div>

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@ -0,0 +1,15 @@
<!--
Copyright 2010 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file.
-->
<table class="layout">
{.repeated section @}
<tr>
<td><a href="{Name|html-esc}">{Name|html-esc}</a></td>
<td width="25">&nbsp;</td>
<td>{Title|html-esc}</td>
</tr>
{.end}
</table>

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@ -6,6 +6,7 @@ include ../../Make.$(GOARCH)
TARG=godoc
GOFILES=\
codewalk.go\
godoc.go\
index.go\
main.go\

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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// The /doc/codewalk/ tree is synthesized from codewalk descriptions,
// files named $GOROOT/doc/codewalk/*.xml.
// For an example and a description of the format, see
// http://golang.org/doc/codewalk/codewalk or run godoc -http=:6060
// and see http://localhost:6060/doc/codewalk/codewalk .
// That page is itself a codewalk; the source code for it is
// $GOROOT/doc/codewalk/codewalk.xml.
package main
import (
"container/vector"
"fmt"
"http"
"io"
"io/ioutil"
"log"
"os"
"regexp"
"sort"
"strconv"
"strings"
"template"
"utf8"
"xml"
)
// Handler for /doc/codewalk/ and below.
func codewalk(c *http.Conn, r *http.Request) {
relpath := r.URL.Path[len("/doc/codewalk/"):]
abspath := absolutePath(r.URL.Path[1:], *goroot)
r.ParseForm()
if f := r.FormValue("fileprint"); f != "" {
codewalkFileprint(c, r, f)
return
}
// If directory exists, serve list of code walks.
dir, err := os.Lstat(abspath)
if err == nil && dir.IsDirectory() {
codewalkDir(c, r, relpath, abspath)
return
}
// If file exists, serve using standard file server.
if err == nil {
serveFile(c, r)
return
}
// Otherwise append .xml and hope to find
// a codewalk description.
cw, err := loadCodewalk(abspath + ".xml")
if err != nil {
log.Stderr(err)
serveError(c, r, relpath, err)
return
}
b := applyTemplate(codewalkHTML, "codewalk", cw)
servePage(c, "Codewalk: "+cw.Title, "", "", b)
}
// A Codewalk represents a single codewalk read from an XML file.
type Codewalk struct {
Title string "attr"
File []string
Step []*Codestep
}
// A Codestep is a single step in a codewalk.
type Codestep struct {
// Filled in from XML
Src string "attr"
Title string "attr"
XML string "innerxml"
// Derived from Src; not in XML.
Err os.Error
File string
Lo int
LoByte int
Hi int
HiByte int
Data []byte
}
// String method for printing in template.
// Formats file address nicely.
func (st *Codestep) String() string {
s := st.File
if st.Lo != 0 || st.Hi != 0 {
s += fmt.Sprintf(":%d", st.Lo)
if st.Lo != st.Hi {
s += fmt.Sprintf(",%d", st.Hi)
}
}
return s
}
// loadCodewalk reads a codewalk from the named XML file.
func loadCodewalk(file string) (*Codewalk, os.Error) {
f, err := os.Open(file, os.O_RDONLY, 0)
if err != nil {
return nil, err
}
defer f.Close()
cw := new(Codewalk)
p := xml.NewParser(f)
p.Entity = xml.HTMLEntity
err = p.Unmarshal(cw, nil)
if err != nil {
return nil, &os.PathError{"parsing", file, err}
}
// Compute file list, evaluate line numbers for addresses.
m := make(map[string]bool)
for _, st := range cw.Step {
i := strings.Index(st.Src, ":")
if i < 0 {
i = len(st.Src)
}
file := st.Src[0:i]
data, err := ioutil.ReadFile(absolutePath(file, *goroot))
if err != nil {
st.Err = err
continue
}
if i < len(st.Src) {
lo, hi, err := addrToByteRange(st.Src[i+1:], 0, data)
if err != nil {
st.Err = err
continue
}
// Expand match to line boundaries.
for lo > 0 && data[lo-1] != '\n' {
lo--
}
for hi < len(data) && (hi == 0 || data[hi-1] != '\n') {
hi++
}
st.Lo = byteToLine(data, lo)
st.Hi = byteToLine(data, hi-1)
}
st.Data = data
st.File = file
m[file] = true
}
// Make list of files
cw.File = make([]string, len(m))
i := 0
for f := range m {
cw.File[i] = f
i++
}
sort.SortStrings(cw.File)
return cw, nil
}
// codewalkDir serves the codewalk directory listing.
// It scans the directory for subdirectories or files named *.xml
// and prepares a table.
func codewalkDir(c *http.Conn, r *http.Request, relpath, abspath string) {
type elem struct {
Name string
Title string
}
dir, err := ioutil.ReadDir(abspath)
if err != nil {
log.Stderr(err)
serveError(c, r, relpath, err)
return
}
var v vector.Vector
for _, fi := range dir {
if fi.IsDirectory() {
v.Push(&elem{fi.Name + "/", ""})
} else if strings.HasSuffix(fi.Name, ".xml") {
cw, err := loadCodewalk(abspath + "/" + fi.Name)
if err != nil {
continue
}
v.Push(&elem{fi.Name[0 : len(fi.Name)-len(".xml")], cw.Title})
}
}
b := applyTemplate(codewalkdirHTML, "codewalkdir", v)
servePage(c, "Codewalks", "", "", b)
}
// codewalkFileprint serves requests with ?fileprint=f&lo=lo&hi=hi.
// The filename f has already been retrieved and is passed as an argument.
// Lo and hi are the numbers of the first and last line to highlight
// in the response. This format is used for the middle window pane
// of the codewalk pages. It is a separate iframe and does not get
// the usual godoc HTML wrapper.
func codewalkFileprint(c *http.Conn, r *http.Request, f string) {
abspath := absolutePath(f, *goroot)
data, err := ioutil.ReadFile(abspath)
if err != nil {
serveError(c, r, f, err)
return
}
lo, _ := strconv.Atoi(r.FormValue("lo"))
hi, _ := strconv.Atoi(r.FormValue("hi"))
if hi < lo {
hi = lo
}
lo = lineToByte(data, lo)
hi = lineToByte(data, hi+1)
// Put the mark 4 lines before lo, so that the iframe
// shows a few lines of context before the highlighted
// section.
n := 4
mark := lo
for ; mark > 0 && n > 0; mark-- {
if data[mark-1] == '\n' {
if n--; n == 0 {
break
}
}
}
io.WriteString(c, `<style type="text/css">@import "/doc/codewalk/codewalk.css";</style><pre>`)
template.HTMLEscape(c, data[0:mark])
io.WriteString(c, "<a name='mark'></a>")
template.HTMLEscape(c, data[mark:lo])
if lo < hi {
io.WriteString(c, "<div class='codewalkhighlight'>")
template.HTMLEscape(c, data[lo:hi])
io.WriteString(c, "</div>")
}
template.HTMLEscape(c, data[hi:])
io.WriteString(c, "</pre>")
}
// addrToByte evaluates the given address starting at offset start in data.
// It returns the lo and hi byte offset of the matched region within data.
// See http://plan9.bell-labs.com/sys/doc/sam/sam.html Table II
// for details on the syntax.
func addrToByteRange(addr string, start int, data []byte) (lo, hi int, err os.Error) {
var (
dir byte
prevc byte
charOffset bool
)
lo = start
hi = start
for addr != "" && err == nil {
c := addr[0]
switch c {
default:
err = os.NewError("invalid address syntax near " + string(c))
case ',':
if len(addr) == 1 {
hi = len(data)
} else {
_, hi, err = addrToByteRange(addr[1:], hi, data)
}
return
case '+', '-':
if prevc == '+' || prevc == '-' {
lo, hi, err = addrNumber(data, lo, hi, prevc, 1, charOffset)
}
dir = c
case '$':
lo = len(data)
hi = len(data)
if len(addr) > 1 {
dir = '+'
}
case '#':
charOffset = true
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
var i int
for i = 1; i < len(addr); i++ {
if addr[i] < '0' || addr[i] > '9' {
break
}
}
var n int
n, err = strconv.Atoi(addr[0:i])
if err != nil {
break
}
lo, hi, err = addrNumber(data, lo, hi, dir, n, charOffset)
dir = 0
charOffset = false
prevc = c
addr = addr[i:]
continue
case '/':
var i, j int
Regexp:
for i = 1; i < len(addr); i++ {
switch addr[i] {
case '\\':
i++
case '/':
j = i + 1
break Regexp
}
}
if j == 0 {
j = i
}
pattern := addr[1:i]
lo, hi, err = addrRegexp(data, lo, hi, dir, pattern)
prevc = c
addr = addr[j:]
continue
}
prevc = c
addr = addr[1:]
}
if err == nil && dir != 0 {
lo, hi, err = addrNumber(data, lo, hi, dir, 1, charOffset)
}
if err != nil {
return 0, 0, err
}
return lo, hi, nil
}
// addrNumber applies the given dir, n, and charOffset to the address lo, hi.
// dir is '+' or '-', n is the count, and charOffset is true if the syntax
// used was #n. Applying +n (or +#n) means to advance n lines
// (or characters) after hi. Applying -n (or -#n) means to back up n lines
// (or characters) before lo.
// The return value is the new lo, hi.
func addrNumber(data []byte, lo, hi int, dir byte, n int, charOffset bool) (int, int, os.Error) {
switch dir {
case 0:
lo = 0
hi = 0
fallthrough
case '+':
if charOffset {
pos := hi
for ; n > 0 && pos < len(data); n-- {
_, size := utf8.DecodeRune(data[pos:])
pos += size
}
if n == 0 {
return pos, pos, nil
}
break
}
// find next beginning of line
if hi > 0 {
for hi < len(data) && data[hi-1] != '\n' {
hi++
}
}
lo = hi
if n == 0 {
return lo, hi, nil
}
for ; hi < len(data); hi++ {
if data[hi] != '\n' {
continue
}
switch n--; n {
case 1:
lo = hi + 1
case 0:
return lo, hi + 1, nil
}
}
case '-':
if charOffset {
// Scan backward for bytes that are not UTF-8 continuation bytes.
pos := lo
for ; pos > 0 && n > 0; pos-- {
if data[pos]&0xc0 != 0x80 {
n--
}
}
if n == 0 {
return pos, pos, nil
}
break
}
// find earlier beginning of line
for lo > 0 && data[lo-1] != '\n' {
lo--
}
hi = lo
if n == 0 {
return lo, hi, nil
}
for ; lo >= 0; lo-- {
if lo > 0 && data[lo-1] != '\n' {
continue
}
switch n--; n {
case 1:
hi = lo
case 0:
return lo, hi, nil
}
}
}
return 0, 0, os.NewError("address out of range")
}
// addrRegexp searches for pattern in the given direction starting at lo, hi.
// The direction dir is '+' (search forward from hi) or '-' (search backward from lo).
// Backward searches are unimplemented.
func addrRegexp(data []byte, lo, hi int, dir byte, pattern string) (int, int, os.Error) {
re, err := regexp.Compile(pattern)
if err != nil {
return 0, 0, err
}
if dir == '-' {
// Could implement reverse search using binary search
// through file, but that seems like overkill.
return 0, 0, os.NewError("reverse search not implemented")
}
m := re.Execute(data[hi:])
if len(m) > 0 {
m[0] += hi
m[1] += hi
} else if hi > 0 {
// No match. Wrap to beginning of data.
m = re.Execute(data)
}
if len(m) == 0 {
return 0, 0, os.NewError("no match for " + pattern)
}
return m[0], m[1], nil
}
// lineToByte returns the byte index of the first byte of line n.
// Line numbers begin at 1.
func lineToByte(data []byte, n int) int {
if n <= 1 {
return 0
}
n--
for i, c := range data {
if c == '\n' {
if n--; n == 0 {
return i + 1
}
}
}
return len(data)
}
// byteToLine returns the number of the line containing the byte at index i.
func byteToLine(data []byte, i int) int {
l := 1
for j, c := range data {
if j == i {
return l
}
if c == '\n' {
l++
}
}
return l
}

View file

@ -108,8 +108,9 @@ func initHandlers() {
func registerPublicHandlers(mux *http.ServeMux) {
mux.Handle(cmdHandler.pattern, &cmdHandler)
mux.Handle(pkgHandler.pattern, &pkgHandler)
mux.Handle("/search", http.HandlerFunc(search))
mux.Handle("/", http.HandlerFunc(serveFile))
mux.HandleFunc("/doc/codewalk/", codewalk)
mux.HandleFunc("/search", search)
mux.HandleFunc("/", serveFile)
}
@ -849,6 +850,8 @@ func readTemplate(name string) *template.Template {
var (
codewalkHTML,
codewalkdirHTML,
dirlistHTML,
errorHTML,
godocHTML,
@ -861,6 +864,8 @@ var (
func readTemplates() {
// have to delay until after flags processing since paths depend on goroot
codewalkHTML = readTemplate("codewalk.html")
codewalkdirHTML = readTemplate("codewalkdir.html")
dirlistHTML = readTemplate("dirlist.html")
errorHTML = readTemplate("error.html")
godocHTML = readTemplate("godoc.html")