I have some form, with css defined and with some textfields, let's use the following as example
<link rel="stylesheet" type="text/css" href="test.css"/>
<form action="/em/call" class="myStyle">
field1:<input text="hello"></input>
<input value="submit" type="submit"/>
</form>
Is it possible to show validation error if field1 is non-empty using Yii built-in validator, if yes, how should I do that?
(In the example given by Yii, it seems using CWidget::form, i am not sure how to customized that in my project, where GUI has been defined)
Yii's validators are built for Yii's architecture and thus you always need at least a model that contains your form data. Before you try to hack your way through something i'd suggest to rewrite your form. It's pretty straightforward and it's documented here:
http://www.yiiframework.com/doc/guide/1.1/en/form.overview
Related
I need a form view and I need its layout to be customized, using directly the Bootstrap 4 styles
How exactly can I do that ?
Also
I need some fields/tabs to appear conditionally (if some values is true) and such conditionally appearing fields need to be in my custom layout
Is this possible ?
How ?
First of all, I could use an example of a custom layout
And then I could use some enlightenment on how the conditional appearing of fields is done, behind the scenes
Thanks in advance
You can create a form view using any html you like. You can also use xpath to load custom css and javascript, such as bootstrap. You should load the xpath straight after your opening form tag.
<xpath expr="." position="inside">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
</xpath>
There a couple of ways to show things conditionally. I find the following example easiest when using the form views:
<div id="my-div" attrs="{'invisible': [('field','==',True)]}">Do not show this text if the field is true</div>
#model Task3.Models.NewUser
<form action="" method="post">
<label>first Name </label>
<input type="text" placeholder="enter name" name="firstName"/>
<input type="text" placeholder="enter last name" name="lastName"/>
<button type="submit">Submit</button>
</form>
This code works even without asp-controller and asp-action. Why should I use those then?
The tag helpers asp-controller and asp-action can be used to automatically generate a target URL but you don’t have to use them. All they do is automatically generate the href attribute for links and action attributes for forms. If you want to fill in thos values manually, there is nothing that’s stopping you from doing that.
However, using the tag helpers has a clear benefit: The actual URL that you have to use depends on various things that affect your application’s routing. So if you use manual values, you have to take that into account. And if your routing changes (for whatever reason), you have to manually update the URLs throughout your templates.
By using the tag helpers, you are attaching the target location to something that is usually rather static: A controller action. So that way, you decouple the template from your routing configuration.
One more note for form actions specifically: If you do not specify a form action, the browser will automatically post to the current URL. So if you have a POST handler on the same route as the form, then you can totally omit the action and depend on that behavior.
Vue.js is ideal library for my case, but I use it on non-SPA page.
Is there a way to bypass syntax v-bind:click? I would like the attributes starts from data-v-* and don't contains :.
My solution (based on accepted answer):
It looks like Vue.js will not pass the exam here.
Knockout proved to be the ideal library for friendly SEO html syntax without compilation templates.
You can use script templates to "hide" your Vue-HTML from the validator. The following validates as HTML5.
<!DOCTYPE html>
<html>
<head>
<title>Whatever</title>
</head>
<body>
<script id="some-template" type="text/template">
<div v-model="foo" v-bind:click="dontCare">Whatever</div>
</script>
<some-template id="app"></some-template>
</body>
</html>
This is not as much of a cheat as it might seem, since Vue-HTML is not HTML, but is in fact a template used for generating HTML (or, I think more accurately, for generating the DOM). But it is a complete cheat in the sense that the generated HTML is never subjected to the validator. :)
Alternatively, you could look at using Knockout, which uses pure HTML5 (what you write is what is delivered to the browser). It is not as performant as Vue, but it is an MVVM framework.
Short answer is: No.
I don't think there is a way to change the templating of Vue. The generated HTML shipped to user will be valid, because modifiers (v-for, v-bind, etc.) will be stripped of your HTML. Framework like Angular, for example, does not strip the multiple "ng-*" properties. For instance, you could write:
<div v-if="model.length" />
The resulting html will be:
<div />
Which is valid and compatible with any W3C validator.
I just come across a good write up for a new ASP.NET Core feature called Tag helpers.
From there, I understood that one can replace the following code:
#model MyProject.Models.Product
#using (Html.BeginForm())
{
<div>
#Html.LabelFor(m => p.Name, "Name:")
#Html.TextBoxFor(m => p.Name)
</div>
<input type="submit" value="Create" />
}
with:
#model MyProject.Models.Product
#addtaghelper "Microsoft.AspNet.Mvc.TagHelpers"
<form asp-controller="Products" asp-action="Create" method="post">
<div>
<label asp-for="Name">Name:</label>
<input asp-for="Name" />
</div>
<input type="submit" value="Save" />
</form>
There's some new syntax such as asp-controller, asp-for, etc. But what does it do? And what's the advantage of this new approach?
The most important improvement I've seen so far is the control it guarantees over your HTML elements. While convenient, the Html helpers used by MVC create problems when you try to do things they weren't built for.
A simple example can be seen when using the TextBox in MVC5:
#Html.TextBoxFor(m => p.Name)
The resulting HTML markup looks like:
<input class="form-control" id="Name" name="Name" type="text" value="">
Nice and simple. But what if you want to add a placeholder attribute? What if you want to use bootstrap's validation states? What if you have some 3rd party super cool javascript library which needs custom attributes. None of these things were possible in the initial release of MVC5. Though they were eventually added via update in the form of htmlAttributes. Even now adding custom attributes is kludgey at best.
#Html.TextBoxFor(m => p.Name,
new {#class="form-control has-error", placeholder="Enter Name",
superCoolFeature="Do something cool"})
While you could argue this is still less code that straight HTML, it is no longer a significant advantage. Worse, this solution still doesn't cover dashes in attributes which are fairly common. If you need them you are stuck with a workaround such as ActionLink htmlAttributes
I've gone down the route of fixing these deficiencies with custom editors, and tried building my own TextBox controls. It became obvious pretty quickly that replacing the included TextBox templates would require a lot of work. Worse, your templates have to have knowledge of any extensions you are adding to use them.
It seems like the inclusion of Bootstrap and other 3rd party tools into MVC have made it more obvious that the current design has problems with extending HTML which need to be fixed. Hopefully the tag helpers implementation is complete enough that we can avoid them in the future.
Not to mention, your Web Designers will have real HTML tags to edit that they recognize to re-design your pages. Designers shouldn't have to be coders and there's enough for these sharp folks to keep up with, studying the moving targets of HTML5 and CSS3 specs.
A few things come to mind:
As #ChrisWalter points out, these tag helpers give HTML tags an Open/Closed quality. Rather than just letting you write extension methods for common HTML patterns, you can extend an HTML element. This lets you pick-and-mix multiple extensions per component, rather than having to choose between them.
HTML Helpers tend to not work super well for elements that need to have inner HTML provided as an argument. They came up with a clever pattern so you can say:
#using (Html.BeginForm(...)){
{
<input ... />
}
But there's nothing about BeginForm() that would force you to put it in a using statement, and there's nothing to prevent you from using incorrect HTML structure. (<input> technically isn't allowed to be directly inside a <form> tag.)
This gives us a really easy transitional stepping stone into the Web Components world of HTML5. A component that you write today for jQuery or Bootstrap to pick up and enhance may make more sense as an Angular 2 or Polymer component in a few years. Using HTML syntax makes it possible to write your HTML the way you want it to look when it's a web component, and have it automatically translated into the structure it has to take on for now (or for specific browsers, later).
Accepted answer is correct but just a correction.
Html Helpers cover dashes in attributes by use of underscore. for example if you want html like
my-attr=value
then you can use html helpers like
#Html.TextBoxFor(m=>m.id,
new { my_attr = value })
then it will convert accordingly.
I know the original question asks about advantages but for the sake of completeness I have to mention one disadvantage:
With tag-helpers enabled you cannot inject C# code inside tag attributes.
I.e. this code will break:
<!-- this won't work -->
<input class="#GetMyClass()">
<!-- this won't work too -->
<input type="checkbox" #(condition ? "checked" : "") >
To work around this problem you can use custom tag helpers or just disable tag helpers altogether like described in this answer: https://stackoverflow.com/a/65281018/56621
P.S. My humble opinion that can be safely ignored: tag helpers are "magic". And "magic" is always bad in programming. If something looks like an HTML tag, walks like a tag and quacks like a tag - then it should probably be an HTML tag. Without me knowning "oh, it's not *really* a tag".
From building a basic web app from the ground up in .NET 7/Razor pages, I haven't encountered a single instance where a tag helper has an advantage over simply coding the HTML. I don't come from an MVC background so maybe that is where the advantage lies but as seen before...Microsoft has released yet another version of wheel-reinvention that instead of making things easier for some simply adds more confusion to others.
I am using ASP.NET MVC 4 HTML.BeginForm and it creates a validation-summary-errors class as
below. This doesn't fit with my layout. Is there a way that I can make it put the
validation div class in a different place?
<form action="/User/Account/Login" method="post" novalidate="novalidate">
<div class="validation-summary-errors">
<ul>
<li>The user name or password provided is incorrect.</li>
</ul>
</div>
<fieldset>
<legend>Local Login</legend>
<ol>
<li>ation-summary-errors in a different position?
Well, sure, it's up to you to put the #Html.ValidationSummary() helper call which generates this markup wherever you want. As far as controlling the exact markup that this helper spits, that would be much more difficult because this helper offers you almost no control over the generated markup.
If you need to have more control you could write a custom helper.
You can use #Html.ValidationMessage("validation-errors") and put it in any HTML tag and then can use CSS to give it a style.