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Questions tagged [opa]

Opa is an open source programming language for both backend and frontend web development. Opa therefore provides a unified syntax and semantics for writing all aspects of a web application: client-side, server-side and database queries. But it’s not only about expressiveness: Opa also features a unique type system that provides strong static typing from the client UI to the MongoDB queries.

Important links:

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What backend platform is Opa running on?

I wonder what backend platform Opa is using for communication with the browsers. My guess would be Node.js.
ajsie
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How do I use JavaScript frameworks with Opa

Is it possible to use existing frontend frameworks like Sproutcore and ExtJS with Opa? If so, where can I find documentation about it?
ajsie
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How to execute queries to the database in Opa?

I've declared a database where the customer data is stored: type Customer = { name : string email: string cp: int } db /customer : Customer I would like to execute certain queries to work with the data such as: Select name where id >…
semoru
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Opa security and bug fixes

I am considering having a look at Opa. While I am comfortable with the usual way of building web applications, the project seems very interesting, and having the client-server communication handled automatically is a real plus. My only concern is…
Andrea
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Opa: Prevent Page Reload when Form Is Submitted

In Opa, how can I prevent a page reload when a form is submitted? When submit is pressed, I want to perform some client-side validation and only submit the form if validation passes. I'm working with this form:
ready()}…
nrw
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is there a mirror of the Opa API documentation?

The api documentation seems to be down right now: http://doc.opalang.org/api/index.html Does anyone know if there's a mirror?
o-town
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Error compiling opa file

I'm new to Opa (and complied languages) - normally develop web apps with Python. I'm following the intro tutorial at http://doc.opalang.org/index.html#_introducing_opa but my hello_chat.opa file won't compile when I run "opa hello_chat.opa". I get…
lander2k2
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Where can I find documentation on all Opa directives?

Looking for docs explaining directives such as @publish, which is mentioned in the "Hello Chat" example.
agentofuser
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Mail function in OPA

Today I need to send email in my OPA apps. Then I'am trying to use opa functions about mail. I am using the module : stdlib.web.mail. And the OPA version : Opa compiler (c) MLstate -- version S3.5 -- build 320 Then, with function Email.try_send…
Mattgu74
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Can different OPA apps share Databases?

I'm just investigating OPA and trying to make the leap from a traditional LAMP background, so here's my first of many newbie questions: Can I have two OPA apps sharing the same database, say one which writes into a database and another that reads…
russellfeeed
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Error during the build from source

I have a 32bit architecture so I must build opa from source. Configure works fine: ./configure -ocamlopt /opt/opa/bin/ocamlopt.opt -ocamlfind /opt/opa/bin/ocamlfind Checking your OS... Linux Checking your architecture... ix86 Checking ocamlopt...…
deep
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Can I use something other than XHTML 1.1 in Opa?

I don't like MLstate's choice regarding XHTML 1.1 in Opa. Is there a way to use HTML 4.01 and HTML5?
stesch
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Secure String.to_int and others

I use String.to_int, and some time i get errors, for example when the string is not a representation of an int. I would like to catch these errors, or test parameter before to use the function. Some ideas ? Thanks
trecouvr
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Why is 'do' needed in the Opa language?

I think newbies are going to be confused by 'do' and I wonder about it from a language design standpoint. You don't want to confuse newbies at this stage of the life of a new language where pretty much everyone is a newbie and you want newbies in…
aneccodeal
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Access a record, after filtering a list of type sum

I have a list of type my_sum = {a : type_a} / {b : type_b} mylist = [{field_only_in_a = "test"} : type_a,{haha=3 ; fsd=4} : type_b] I want to do that : result = List.find( a -> match a with | {a = _} -> true …
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