An Objective C implementation of the Mustache template language. Based on the Ruby implementation and inspired by ctemplate and et, Mustache is a framework-agnostic way to render logic-free views.
I use this to help quickly generate html fed to the UIWebView control. UIWebView is a great way to have nicely formatted content on the iPhone/iPad without having to mess with UILabels and positioning. Just code up the HTML/CSS, feed it to UIWebView, and off you go!
It's only a subset of standard Mustache features for now. Feel free to fork and improve!!
Mustache templates consist of two parts, a template with "tags" and a view object that has keys (using KVC) that match those tags. The templates are almost completely devoid of logic. All the data that is used to populate the template either must be calculated by the view or stored using KVC in the view.
The simplest view for Objective C is an instance NSDictionary.
NSDictionary *view = [NSDictionary dictionaryWithObjectsAndKeys:
@"James", @"firstName",
@"Kirk", @"lastName",
nil];
NSString *template = @"Hello. My name is {{firstName}} {{lastName}}";
NSString *result = [NLObjectiveMustache stringFromTemplate:template view:view];
// result == @"Hello. My name is James Kirk"
A template is composed of tags delimited by double braces. Inside the braces
are keys that get looked up in the view object using
valueForKey:(NSString *).
If a key referenced by a tag is missing, then the tag is just ignored. As long
as the view object returns nil for that key. NSDictionary works great for
this because it returns nil for any key that it doesn't know about.
To use a single conditional section you prefix the opening tag with # and
the closing tag with /. The behaviour of the conditional section depends
on the resulting value and type of the evaluated key.
The section is rendered if the key returns anything non-nil.
{{#shouldRenderGreeting}}
Hello, my name is {{firstName}} {{lastName}}
{{/shouldRenderGreeting}}
When the conditional evaluates to an enumerable object, the section will be
rendered once for every item in the enumeration. An enumerable is an object
that responds to objectEnumerator and returns an object that is of kind
NSEnumerator. Each item in the enumeration will be set as the current
context for rendering the section. If the item context does not provide
a specified key, it will be searched for in the original view.
<ol>
{{#peopleList}}
<li>Hello, my name is {{firstName}} {{lastName}}</li>
{{/peopleList}}
</ol>
By default, ObjectiveMustache HTML escapes everything interpolated. If you
want to stop that from happening, use three braces like so:
{{{dontEscapeMe}}}
If a key returns nil or false, then the view just ignores the tag.
NSDictionary works great for a view in this case because if a key wasn't set
on it, it just returns nil. If you pass in your own custom object as a view,
then you'll either need to ensure that every key asked for returns nil, or
override the Key Value Coding methods to return nil on any unknown key.
Because of the magic of Key Value Coding, any methods you define on your custom object automatically become keys.
@implementation CustomViewObject
- (NSString *)methodsAreKeys
{
// Now a template can have {{methodsAreKeys}} and this string
// gets inserted
return @"Yes, yes they are!";
}
@end
The unit test is written using the SenTestingKit framework and the project in
the repo is set up with the unit testing target. Fire up Xcode and compile it,
or just run make at the terminal to run the suite.
Released under the MIT License
Copyright (c) 2010 Navel Labs, Ltd.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.