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[docs/tutorials,#113][s]: rework and extend section on records in basics tutorial and start section on filters in query tutorial.

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Rufus Pollock
2012-07-09 01:32:59 +01:00
parent d599f75e85
commit d387eca8cd
2 changed files with 72 additions and 13 deletions
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51
docs/tutorial-basics.markdown
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@@ -58,13 +58,11 @@ var dataset = new recline.Model.Dataset({
});
</script>
## Records, Fields and more
## A Dataset and its Records
Now that we have created a Dataset, we can use it.
For example, let's display some information about the Dataset and its records:
<div class="alert alert-info">You can find out more about Dataset and Records in the <a href="models.html">reference documentation</a></div>
For example, let's display some information about the Dataset and its records using some of the key Dataset attributes: `recordCount` and `records`.
{% highlight javascript %}
{% include tutorial-basics-ex-1.js %}
@@ -79,9 +77,42 @@ $('.ex-1').html('');
{% include tutorial-basics-ex-1.js %}
</script>
Note how the last geo attribute just rendered as `[object Object]`. This is because the Dataset is treating that field value as a string. Let's now take a look at the Dataset fields in more detail.
### Records
### Fields
`Dataset.records` is a Backbone Collection of `Record`s resutling from latest query. This need not (and usually isn't) **all** the records in this Dataset since the latest query need not have matched all records.
<div class="alert alert-info">
Note that on initialization, a Dataset automatically queries for the first 100 records so this is what will usually be available in th <code>records</code> attribute. If you did want all records loaded into <code>records</code> at the start just requery after fetch has completed:
{% highlight javascript %}
// for the async case need to put inside of done
dataset.fetch().done(function() {
dataset.query({size: dataset.recordCount});
});
{% endhighlight %}
</div>
As a Backbone Collection it supports all the standard Backbone collection functionality including methods like `each` and `filter`:
{% highlight javascript %}
dataset.records.each(function(record) {
console.log(record.get('x') * 2);
});
var filtered = dataset.records.filter(function(record) {
return (record.get('z') > 4 && record.get('z') < 18);
});
// get all the values for a given attribute/field/column
var xvalues = dataset.records.pluck('x');
// calls toJSON on all records at once
dataset.records.toJSON();
{% endhighlight %}
<div class="alert alert-info">Want to know more about Dataset and Records? Check out the <a href="models.html">reference documentation</a></div>
## Fields
In addition to Records, a Dataset has <a href="models.html#field">Fields</a> stored in the `fields` attribute. Fields provide information about the fields/columns in the Dataset, for example their id (key name in record), label, type etc.
@@ -100,7 +131,11 @@ $('.ex-fields').html('');
{% include tutorial-basics-ex-fields.js %}
</script>
As can be seen all fields have the default type of 'string'. Let's change the geo field to have type geo\_point and see what affect that has on displaying of the dataset (for good measure we'll also set the label):
As can be seen all fields have the default type of 'string'.
As you may have noticed above the last geo attribute of the dataset just rendered as `[object Object]`. This is because the Dataset is treating that field value as a string. Let's now take a look at the Dataset fields in more detail.
Let's change the geo field to have type geo\_point and see what affect that has on displaying of the dataset (for good measure we'll also set the label):
{% highlight javascript %}
{% include tutorial-basics-ex-fields-2.js %}
@@ -113,5 +148,5 @@ $('.ex-fields-2').html('');
{% include tutorial-basics-ex-fields-2.js %}
</script>
As can be seen the rendering of the field has changed. This is because the `recordSummary` method uses the Record.getFieldValue function which in turn renders a record field using the Field's renderer function. This function varies depending on the type and can also be customized (see the <a href="models.html#field">Field documentation</a>).
As can be seen the rendering of the field has changed. This is because the `summary` method uses the Record.getFieldValue function which in turn renders a record field using the Field's renderer function. This function varies depending on the type and can also be customized (see the <a href="models.html#field">Field documentation</a>).