browser-couch: tutorial.html annotate

annotate tutorial.html @ 93:af36b00306d0

Typo fix

author	Atul Varma <varmaa@toolness.com>
date	Tue, 21 Apr 2009 10:11:07 -0700
parents	093e51c6aa3c
children	86158b61b732

rev	line source
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	2 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	3 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	4 <head>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	5 <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	6 <link rel="stylesheet" type="text/css" media="all"
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	7 href="css/tutorial.css" />
89 c96ebbbe03d6 Fixed title Atul Varma <varmaa@toolness.com> parents: 87 diff changeset	8 <title>BrowserCouch Tutorial</title>
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	9 </head>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	10 <body>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	11 <div id="content" class="documentation">
86 f65007998121 added more to tutorial intro Atul Varma <varmaa@toolness.com> parents: 84 diff changeset	12 <h1>BrowserCouch Tutorial</h1>
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	13
81 38abd7bc4886 Added intro to tutorial text. Atul Varma <varmaa@toolness.com> parents: 80 diff changeset	14 <p>This is a brief introduction to using the BrowserCouch API and the
38abd7bc4886 Added intro to tutorial text. Atul Varma <varmaa@toolness.com> parents: 80 diff changeset	15 MapReduce mechanism. If you haven't already read it, you may want to
82 90854d908f0b Minor change to tutorial Atul Varma <varmaa@toolness.com> parents: 81 diff changeset	16 check out the <a class="intra-wiki" href="index.html">introduction</a>
81 38abd7bc4886 Added intro to tutorial text. Atul Varma <varmaa@toolness.com> parents: 80 diff changeset	17 to learn more about why this style of querying is being explored as an
38abd7bc4886 Added intro to tutorial text. Atul Varma <varmaa@toolness.com> parents: 80 diff changeset	18 alternative to SQL for client-side Web Storage.</p>
38abd7bc4886 Added intro to tutorial text. Atul Varma <varmaa@toolness.com> parents: 80 diff changeset	19
86 f65007998121 added more to tutorial intro Atul Varma <varmaa@toolness.com> parents: 84 diff changeset	20 <p>It should also be noted that BrowserCouch is by no means "mature"
f65007998121 added more to tutorial intro Atul Varma <varmaa@toolness.com> parents: 84 diff changeset	21 software. It currently lacks a lot of CouchDB's features that it ought
f65007998121 added more to tutorial intro Atul Varma <varmaa@toolness.com> parents: 84 diff changeset	22 to have, and its API is not stable at all.</p>
f65007998121 added more to tutorial intro Atul Varma <varmaa@toolness.com> parents: 84 diff changeset	23
87 ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	24 <p>Finally, a note about the code examples in this tutorial: they're
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	25 actually being executed in your browser, and their output is sometimes
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	26 being displayed in this tutorial too. While this helps ensure that the
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	27 software is working as intended and also allows for some interactive
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	28 learning opportunities, right now it also means that some parts of the
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	29 code examples may look a bit unusual. Furthermore, if you see any
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	30 conspicuously blank areas in this tutorial, it could be because the
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	31 tutorial code crashed—our apologies if this occurs.</p>
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	32
86 f65007998121 added more to tutorial intro Atul Varma <varmaa@toolness.com> parents: 84 diff changeset	33 <p>With that out of the way, let's get started.</p>
f65007998121 added more to tutorial intro Atul Varma <varmaa@toolness.com> parents: 84 diff changeset	34
87 ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	35 <h1>Getting Started</h1>
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	36
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	37 <p>Suppose we want to add offline support for a blog. To get a
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	38 database called <tt>blog-posts</tt> in BrowserCouch, you can use the
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	39 following function:</p>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	40
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	41 <div class="example-code">
73 8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	42 BrowserCouch.get('blog-posts', onRetrieveCb, new FakeStorage());
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	43 </div>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	44
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	45 <p>It's clear that the first parameter is the name of the database we
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	46 want; the second parameter is the callback that will be passed the
80 042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	47 database once it's fetched.</p>
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	48
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	49 <p>The third parameter specifies the engine that will be used to
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	50 persistently store our database across browsing sessions. In this case
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	51 we're using <tt>FakeStorage</tt>, which just stores everything
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	52 non-persistently in memory for the sake of example. We could just as
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	53 easily leave out the third parameter to have BrowserCouch figure out
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	54 the best storage backend based on our browser's capabilities.</p>
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	55
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	56 <p>If the database doesn't already exist, an empty one will be created
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	57 for us. Putting blog posts into the database can be done via
73 8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	58 an <tt>onRetrieveCb()</tt> function like this:</p>
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	59
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	60 <div class="example-code">
73 8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	61 function onRetrieveCb(db) {
8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	62 blogDb = db;
8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	63 blogDb.put(
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	64 [{id: 0, author: 'Myk', title: 'Burritos', content: 'Burritos are yum.'},
73 8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	65 {id: 1, author: 'Thunder', title: 'Bacon', content: 'I like bacon.'},
8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	66 {id: 2, author: 'Thunder', title: 'Beer', content: 'Beer is good too.'}],
80 042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	67 onPutCb
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	68 );
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	69 };
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	70 </div>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	71
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	72 <p>Every item we put into our database needs to have an <tt>id</tt>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	73 attribute, but aside from that, the item can contain any
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	74 JSON-encodable data.</p>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	75
80 042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	76 <p>Now that we've put some data into our database, we can play around
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	77 with generating views on the data using the <a
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	78 href="http://en.wikipedia.org/wiki/MapReduce">MapReduce</a> mechanism.
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	79 For instance, here's an ad-hoc view using only the map phase that
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	80 organizes all the post titles by author:</p>
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	81
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	82 <div class="example-code">
80 042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	83 function onPutCb() {
73 8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	84 blogDb.view({
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	85 map: function(doc, emit) {
73 8f0b18026782 Changed around a few things in the tutorial. Atul Varma <varmaa@toolness.com> parents: 70 diff changeset	86 emit(doc.author, doc.title);
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	87 },
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	88 finished: function(result) {
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	89 displayInElement(result, 'author-keyed-view');
74 4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	90 tryAnotherView();
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	91 }
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	92 });
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	93 }
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	94 </div>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	95
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	96 <p>The output placed in the <tt>author-keyed-view</tt> element is:</p>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	97
83 b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	98 <div class="example-output" id="author-keyed-view"></div>
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	99
80 042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	100 <p>As you can see, BrowserCouch essentially iterated over all of the
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	101 blog posts, passing each one to <tt>map()</tt>, along with an
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	102 arbitrary function called <tt>emit()</tt>. The <tt>map()</tt>
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	103 function then emitted key-value pairs which show up in the view. It's
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	104 worth noting that <tt>map()</tt> can call <tt>emit()</tt> as much as
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	105 it wants to; each call will add a new row to the view.</p>
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	106
74 4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	107 <p>We could also try creating another view that adds a
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	108 <tt>reduce()</tt> function to group together the blog post titles with
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	109 the authors:</p>
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	110
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	111 <div class="example-code">
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	112 function tryAnotherView() {
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	113 blogDb.view({
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	114 map: function(doc, emit) {
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	115 emit(doc.author, doc.title);
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	116 },
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	117 reduce: function(keys, values) {
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	118 return values;
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	119 },
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	120 finished: function(result) {
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	121 displayInElement(result, 'author-titles-view');
84 dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	122 findRows(result);
74 4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	123 }
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	124 });
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	125 }
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	126 </div>
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	127
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	128 <p>The output is as follows:</p>
4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	129
83 b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	130 <div class="example-output" id="author-titles-view"></div>
74 4450be5d1b2f Added reduce() example to the tutorial. Atul Varma <varmaa@toolness.com> parents: 73 diff changeset	131
80 042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	132 <p>The <tt>reduce()</tt> mechanism is a bit harder to
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	133 understand. Essentially, BrowserCouch takes all the rows generated by
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	134 <tt>map()</tt> and generates a new list of key-value rows, where the
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	135 value of each row is the list of all values that match the row's key.
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	136 This explains what the <tt>values</tt> argument passed to
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	137 <tt>reduce()</tt> is.</p>
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	138
87 ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	139 <p>The <tt>keys</tt> argument is a list of 2-tuples, the first of
80 042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	140 which is the key, and the second of which is the document id that
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	141 emitted the key during the map phase.</p>
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	142
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	143 <p>The <tt>reduce()</tt> function is called for each unique key, and
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	144 its return value is the value for its key in the final view.</p>
042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	145
83 b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	146 <p>Once you've got a view, you can use the view's <tt>findRow()</tt>
93 af36b00306d0 Typo fix Atul Varma <varmaa@toolness.com> parents: 91 diff changeset	147 method to find the first row whose key matches (or is closest to) the
83 b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	148 one you provide. For example:</p>
b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	149
b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	150 <div class="example-code">
84 dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	151 function findRows(result) {
dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	152 var rowIndex = result.findRow('Thunder');
dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	153 displayInElement(result.rows[rowIndex], 'author-find-row-view');
dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	154 tryMyView();
83 b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	155 }
b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	156 </div>
b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	157
b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	158 <p>The output for this one is:</p>
b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	159
b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	160 <div class="example-output" id="author-find-row-view"></div>
b95fc8f8a344 Added section on using findRow(). Atul Varma <varmaa@toolness.com> parents: 82 diff changeset	161
78 17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	162 <h1>Now You Try!</h1>
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	163
84 dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	164 <p>If your eyes are crossed right now, no worries—most people
dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	165 take a long time to understand exactly what MapReduce is doing. That
dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	166 said, the easiest way to understand how MapReduce works is just to
dbe68e5af673 Shortened tutorial code a bit. Atul Varma <varmaa@toolness.com> parents: 83 diff changeset	167 play around with creating your own view.</p>
80 042eb025bce5 Added more tutorial text. Atul Varma <varmaa@toolness.com> parents: 78 diff changeset	168
91 093e51c6aa3c Minor rewording Atul Varma <varmaa@toolness.com> parents: 89 diff changeset	169 <p>You can use the text field below to do just that. Just press the
093e51c6aa3c Minor rewording Atul Varma <varmaa@toolness.com> parents: 89 diff changeset	170 tab key when you're done making changes to recompute the view.</p>
78 17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	171
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	172 <textarea class="example-code try-code">
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	173 function tryMyView() {
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	174 blogDb.view({
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	175 map: function(doc, emit) {
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	176 emit(doc.author, doc.title);
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	177 },
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	178 reduce: function(keys, values) {
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	179 return values;
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	180 },
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	181 finished: function(result) {
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	182 displayInElement(result, 'try-my-view');
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	183 }
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	184 });
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	185 }
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	186 </textarea>
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	187
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	188 <p>Here's the output to the above view:</p>
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	189
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	190 <div class="example-output" id="try-my-view"></div>
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	191
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	192 <h1>Where To Go From Here</h1>
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	193
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	194 <p>There's features in the API that aren't covered here, so check out
17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	195 the check out the <a class="intra-wiki"
87 ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	196 href="index.html#js/tests.js">test suite's annotated source code</a>
ebf8936fc696 More tutorial additions. Atul Varma <varmaa@toolness.com> parents: 86 diff changeset	197 for more examples.</p>
78 17ce8b6be452 Added a 'now you try' section and a 'where to go from here' section to the tutorial. Atul Varma <varmaa@toolness.com> parents: 74 diff changeset	198
70 36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	199 <script src="js/ext/jquery.js"></script>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	200 <script src="js/browser-couch.js"></script>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	201 <script src="js/tutorial.js"></script>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	202 </body>
36e47760ee5b Added a work-in-progress tutorial that auto-generates parts of itself. Atul Varma <varmaa@toolness.com> parents: diff changeset	203 </html>

Mercurial > browser-couch

annotate tutorial.html @ 93:af36b00306d0