Mercurial > urweb
comparison demo/prose @ 781:c884a42599f3
crud3 demo
| author | Adam Chlipala <adamc@hcoop.net> |
|---|---|
| date | Sun, 03 May 2009 16:00:43 -0400 |
| parents | 0084af7af35a |
| children | 305bc0a431de |
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| 780:0084af7af35a | 781:c884a42599f3 |
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| 229 | 229 |
| 230 crud2.urp | 230 crud2.urp |
| 231 | 231 |
| 232 <p>This example shows another application of <tt>Crud.Make</tt>. We mix one standard column with one customized column. We write an underscore for the <tt>Inject</tt> field of meta-data, since the type class facility can infer that witness.</p> | 232 <p>This example shows another application of <tt>Crud.Make</tt>. We mix one standard column with one customized column. We write an underscore for the <tt>Inject</tt> field of meta-data, since the type class facility can infer that witness.</p> |
| 233 | 233 |
| 234 crud3.urp | |
| 235 | |
| 236 <p>One thing that is unclear from the previous examples is how to provide more complex, multi-input widgets for taking input meant for particular fields. The signature of <tt>Crud.Make</tt> forces every widget to define exactly one input. The <tt><subform></tt> tag, the simpler cousin of the <tt><subforms></tt> tag that we saw earlier, provides a fix for this problem. Via <tt><subform></tt>, an arbitrary form can be turned into a single record-valued input.</p> | |
| 237 | |
| 238 <p>We use that possibility here to define a silly widget for a <tt>string</tt> column, which concatenates the values entered into two different textboxes.</p> | |
| 239 | |
| 234 alert.urp | 240 alert.urp |
| 235 | 241 |
| 236 <p>Ur/Web makes it easy to write code whose execution should be distributed between the web server and client web browsers. Server-side code is compiled to efficient native code, and client-side code is compiled to JavaScript. Ur/Web programmers don't need to worry about these details, because the language and standard library provide a uniform ML-like interface for the whole process.</p> | 242 <p>Ur/Web makes it easy to write code whose execution should be distributed between the web server and client web browsers. Server-side code is compiled to efficient native code, and client-side code is compiled to JavaScript. Ur/Web programmers don't need to worry about these details, because the language and standard library provide a uniform ML-like interface for the whole process.</p> |
| 237 | 243 |
| 238 <p>Here's an example of a button that, when clicked, opens an alert dialog on the client.</p> | 244 <p>Here's an example of a button that, when clicked, opens an alert dialog on the client.</p> |