I am trying to bind items that belong to a Dictionary and it all works fine, until I run into KeyValuePairs where the Key contains square brackets. For example, imagine this contrived scenario:
model = new MyModel {
MyDict = new Dictionary<string, string> {
{ "Apple[1]", "Green" }
}
}
I then create a form as follows:
Html.EditorFor(model => model.MyDict["Apple[1]"])
As expected, the field looks like this:
<input id="MyDict_Apple_1__" name="MyDict[Apple[1]]"> type="text" value="Green">
The problem is that when the form is submitted, the ModelBinder drops the last bracket: ModelBindingContext.ModelName is "MyDict[Apple[1]".
Is this a bug in the DefaultModelBinder, or am I missing something?
Update:
I found that there's a bug in how FormValueProvider reads keys from the data. Specifically, the bug is in the GetKeyFromEmptyPrefix method of Microsoft.AspNetCore.Mvc.Internal.PrefixContainer.
For now I'm working around the issue by using the old binding syntax, with separate fields for the Key and Value:
<input type="hidden" name="MyDict[0].Key" value="Apple[1]" />
<input type="text" name="MyDict[0].Value" value="Green" />
I have used the uib-typeahead directive as follows :
<input type="text" id="search-box" class="form-control" data-ng-model="searchBar.search.searchString"
typeahead-on-select="searchBar.gotoPartDetails($item, $model, $label, $event)" uib-typeahead="result as result.partNumber+' '+result.lineDesc+' '+result.partDesc for result in searchBar.textTyped($viewValue)"
placeholder="Search by part number, product type, product line, keyword" typeahead-focus-first="searchBar.search.firstSelect" typeahead-popup-template-url="app/components/header/search-bar/typeahead-popup.html" typeahead-template-url="{{searchBar.search.typeaheadTemplate}}"
data-ng-focus="searchBar.focus()" data-ng-blur="searchBar.blur()">
I am basically using the "searchBar.search.firstSelect" scope variable to enable or disable first select. On controller load searchBar.search.firstSelect is set to false and based on the size of the length data displayed. If the typeahead is showing just one data in the options I am setting searchBar.search.firstSelect to true. But this is not reflecting in the UI. What do I do?
I want to ask in MVC3+; data passed from controller in form of modle or viewbag is the data encoded by default or I do have to ?
Do you mean HTML encoded? They're not, no.
This means that if you have a string property that contains the value "<b>some text</b>" then the property contents is exactly that.
If, however, you try to print this output to the View with #MyProperty then, by default, the string will be HTML-encoded by MVC. So the output would become <some text>.
You can escape this by using #Html.Raw(MyProperty).
Remember that the term 'encoded' is a bit vague. Try to be specific with what encoding you're referring to.
MVC proactively tries to encode values to prevent cross-site scripting.
#* This is HTML Encoded *#
#Model.Value
#* This value is not encoded *#
#Html.Raw(Model.Value)
#* The URL gets URL Encoded *#
<a href="#Url" />
This Razor code
# {
bool disabled = false;
bool readonly = true;
string className = null;
}
<input type="text" disabled="#disabled" readonly="#readonly" class="#className" />
Actually produces this output
<input type="text" readonly="readonly" />
A value of null or false causes the Razor view engine to not render the attribute at all.
If you did want something like this data-soldout="false" then you need to do:
data-soldout="#Html.Raw(isSoldout)" or data-soldout="#isSoldout.ToString()"
I'm just now starting to learn ASP.NET MVC. How would I go about creating a reusable tri-state checbox? In WebForms this would be a control, but I don't know the MVC equivalent.
Add a TriStateCheckBox (or TriStateCheckBoxFor if you use the strongly typed overloads) extension method to HtmlHelper and add the namespace of that extension method class to the namespaces section of your web.config.
As for the implementation, I'd recommend having at look at the InputExtensions source on codeplex and using that to create your own.
Limitations:
View Rendering - When rendering HTML content, there is no attribute you can possibly place on an <input type="checkbox" /> that will give it the property indeterminate.
At some point, you'll have to use JavaScript to grab the element and set the indeterminate property:
// vanilla js
document.getElementById("myChk").indeterminate = true;
// jQuery
$("#myCheck).prop("indeterminate", true);
Form Data - model binding will always be limited to what values are actually sent in the request, either from the url or the data payload (on a POST).
In this simplified example, both unchecked and indeterminate checkboxes are treated identically:
And you can confirm that for yourself in this Stack Snippet:
label {
display: block;
margin-bottom: 3px;
}
<form action="#" method="post">
<label >
<input type="checkbox" name="chkEmpty">
Checkbox
</label>
<label >
<input type="checkbox" name="chkChecked" checked>
Checkbox with Checked
</label>
<label >
<input type="checkbox" name="chkIndeterminate" id="chkIndeterminate">
<script> document.getElementById("chkIndeterminate").indeterminate = true; </script>
Checkbox with Indeterminate
</label>
<label >
<input name="RegularBool" type="checkbox" value="true">
<input name="RegularBool" type="hidden" value="false">
RegularBool
</label>
<input type="submit" value="submit"/>
</form>
Model Binding - Further, model binding will only occur on properties that are actually sent. This actually poses a problem even for regular checkboxes, since they won't post a value when unchecked. Value types do always have a default value, however, if that's the only property in your model, MVC won't new up an entire class if it doesn't see any properties.
ASP.NET solves this problem by emitting two inputs per checkbox:
Note: The hidden input guarantees that a 'false' value will be sent even when the checkbox is not checked. When the checkbox is checked, HTTP is allowed to submit multiple values with the same name, but ASP.NET MVC will only take the first instance, so it will return true like we'd expect.
Render Only Solution
We can render a checkbox for a nullable boolean, however this really only works to guarantee a bool by converting null → false when rendering. It is still difficult to share the indeterminate state across server and client. If you don't need to ever post back indeterminate, this is probably the cleanest / easiest implementation.
Roundtrip Solution
As there are serious limitations to using a HTML checkbox to capture and post all 3 visible states, let's separate out the view of the control (checkbox) with the tri-state values that we want to persist, and then keep them synchronized via JavsScript. Since we already need JS anyway, this isn't really increasing our dependency chain.
Start with an Enum that will hold our value:
/// <summary> Specifies the state of a control, such as a check box, that can be checked, unchecked, or set to an indeterminate state.</summary>
/// <remarks> Adapted from System.Windows.Forms.CheckState, but duplicated to remove dependency on Forms.dll</remarks>
public enum CheckState
{
Checked,
Indeterminate,
Unchecked
}
Then add the following property to your Model instead of a boolean:
public CheckState OpenTasks { get; set; }
Then create an EditorTemplate for the property that will render the actual property we want to persist inside of a hidden input PLUS a checkbox control that we'll use to update that property
Views/Shared/EditorTemplates/CheckState.cshtml:
#model CheckState
#Html.HiddenFor(model => model, new { #class = "tri-state-hidden" })
#Html.CheckBox(name: "",
isChecked: (Model == CheckState.Checked),
htmlAttributes: new { #class = "tri-state-box" })
Note: We're using the same hack as ASP.NET MVC to submit two fields with the same name, and placing the HiddenFor value that we want to persist first so it wins. This just makes it easy to traverse the DOM and find the corresponding value, but you could use different names to prevent any possible overlap.
Then, in your view, you can render both the property + checkbox using the editor template the same way you would have used a checkbox, since it renders both. So just add this to your view:
#Html.EditorFor(model => model.OpenTasks)
The finally piece is to keep them synchronized via JavaScript on load and whenever the checkbox changes like this:
// on load, set indeterminate
$(".tri-state-hidden").each(function() {
var isIndeterminate = this.value === "#CheckState.Indeterminate";
if (isIndeterminate) {
var $box = $(".tri-state-box[name='" + this.name + "'][type='checkbox']");
$box.prop("indeterminate", true);
}
});
// on change, keep synchronized
$(".tri-state-box").change(function () {
var newValue = this.indeterminate ? "#CheckState.Indeterminate"
: this.checked ? "#CheckState.Checked"
: "#CheckState.Unchecked";
var $hidden = $(".tri-state-hidden[name='" + this.name + "'][type='hidden']");
$hidden.val(newValue);
});
Then you can use however you'd like in your business model. For example, if you wanted to map to a nullable boolean, you could use the CheckState property as a backing value and expose/modify via getters/setters in a bool? like this:
public bool? OpenTasksBool
{
get
{
if (OpenTasks == CheckState.Indeterminate) return null;
return OpenTasks == CheckState.Checked;
}
set
{
switch (value)
{
case null: OpenTasks = CheckState.Indeterminate; break;
case true: OpenTasks = CheckState.Checked; break;
case false: OpenTasks = CheckState.Unchecked; break;
}
}
}
Alternative Solution
Also, depending on your domain model, you could just use Yes, No, ⁿ/ₐ radio buttons
ASP.NET MVC certainly doesn't provide such component, actually it simply relies on the standard elements available in HTML but you may want to check out this solution.
I have a field in my domain object which I define as an Integer...
Integer minPrice
I then access it in a GSP page as follows:
${fieldValue(bean: myBean, field: 'minPrice')}
and what I get in my HTML is...
100,000
which is not an Integer, it's a String. Worse still it's a formatted String in a particular locale.
This is a problem because I have a SELECT control on an HTML FORM which has a (non-ordinal) range of values for minPrice which I want to store in my domain object as integers, and I don't want to store an index to some array of values that I have to repeatedly map back and forth between, I want the value itself.
My select control looks like this...
<g:select name="minPrice"
value="${fieldValue(bean: personInstance, field: 'minPrice')}"
onchange="setDirty()"
noSelection='${['0':'Select a number...']}'
from="${[
['name':'100,000', 'id':100000],
['name':'200,000', 'id':200000],
['name':'300,000', 'id':300000]
]}"
optionKey="id" optionValue="name"
/>
When I get the value from the SELECT field to post back to the server it correctly has an Integer value, which I persist. However the return trip never pre-selects the right row in the drop-down because the value is this comma separated String.
This works fine elsewhere in my code for small numbers where the comma formatting doesn't come into play, and the round-trip in and out of the SELECT is successful. But values >999 don't work.
The docs say "This tag will inspect a bean which has been the subject of data binding and obtain the value of the field either from the originally submitted value contained within the bean's errors object populating during data binding or from the value of a bean's property. Once the value is obtained it will be automatically HTML encoded."
It's that last bit that I want to avoid as it appears to format Integers. So, what little bit of Grails/GSP magic do I need to know so I can get my Integer to be rendered as an integer into my SELECT and pre-select the right row?
EDIT:
I have tried some further things based on the answers below, with pretty disappointing results so far...
If I put the <gformatNumber/> tag in my <g:select/> I get the page code as text in the browser.
<g:select name="minPrice"
value='<g:formatNumber number="${fieldValue(bean: personInstance, field: 'minPrice')}" format="#" />'
onchange="setDirty()"
noSelection='${['0':'Select a number...']}'
from="${[
['name':'100,000', 'id':100000],
['name':'200,000', 'id':200000],
['name':'300,000', 'id':300000],
]}"
optionKey="id" optionValue="name"
/>
Using the number format tag from GSP on my Integer value of 100000 like this...
var x = <g:formatNumber number="${fieldValue(bean: personInstance, field: 'minPrice')}" format="#" />;
gives 100. Remember that the fieldValue gives back 100,000, so this is not a surprise.
If I use the jsp taglib like this...
<%# taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
var y = <fmt:formatNumber value="${fieldValue(bean: personInstance, field: 'minPrice')}" pattern=".00"/>;
I get an error from the page compiler Cannot format given Object as a Number.
I guess I have a wider concern than I can't seem to get an Integer value as a genuine integer into my code if it is greater than 999 because of the default (and unconfigurable) behaviour of the fieldValue directive. However my specific problem of not being able to pre-select an Integer value in a SELECT control is not going away. At the moment I'm at a bit of a loss.
Anyone have any further ideas?
Do you want to show the raw number? like 100000?
You can get the field directly:
${myBean.minPrice}
I think you have at least two possible solutions.
One is to use the JSTL taglib as described in the docs.
Another, cooler way is to use the 'formatNumber' tag included with grails - also in the docs.
For your purpose, the use of that tag might look like this:
<g:formatNumber number="${fieldValue(bean: myBean, field: 'minPrice')}" format="######" />
Use the 'groupingUsed' attribute in combination with your format:
<g:formatNumber number="${fieldValue(bean: personInstance, field: 'minPrice')}"
format="#"
groupingUsed="true" />
Better use custom PropertyEditor in order not to bother with formatNumber tag every time you output a value.
Like, declare a bean in resources.groovy:
myOwnCustomEditorRegistrar(CustomEditorRegistrar)
And create your class:
class CustomEditorRegistrar implements PropertyEditorRegistrar {
void registerCustomEditors(PropertyEditorRegistry registry) {
registry.registerCustomEditor(BigDecimal.class, new MyBigDecimalEditor(BigDecimal.class))
}
}
Change
var x = <g:formatNumber number="${fieldValue(bean: personInstance, field: 'minPrice')}" format="#" />;
to
var x = <g:formatNumber number="${personInstance.minPrice}" format="#" />;
I found the best way to handle this was doing what Victor Sergienko (upped btw) hinted at with using a PropertyEditor.
Create an editor for Integer, put in src/groovy:
class IntegerEditor extends PropertyEditorSupport {
void setAsText(String s) {
if (s) value = s as Integer
}
public String getAsText() {
value
}
}
and register it using a PropertyEditorRegistrar (also in src/groovy):
class MyEditorRegistrar implements PropertyEditorRegistrar {
public void registerCustomEditors(PropertyEditorRegistry reg) {
reg.registerCustomEditor(Integer, new IntegerEditor())
}
}
add your registrar into the spring config (grails-app/conf/spring/resource.groovy):
beans = {
customEditorRegistrar(MyEditorRegistrar)
}
From now on any Integers that are bound, receive errors (or not) and then redisplayed with the fieldValue tag should be displayed by Integer's default toString - you can customise this behaviour in the editor by amending the getAsText implementation.
Personally I would create a wrapper for this kind of thing so you can set up an editor just for that type rather than across the board for a frequently used type. Though I realise this would mean a little bit of mapping when persisting to the DB...
I have a solution/work-round... The answer seems to be, "do nothing".
Instead of trying to parse the stringified number back into an integer, I left it as a formatted string for the purposes of the select. This meant I had to change my from values as follows:
<g:select name="minPrice"
value="${fieldValue(bean: personInstance, field: 'minPrice')}"
onchange="setDirty()"
noSelection='${['0':'Select a number...']}'
from="${[
['name':'100,000', 'id':'100,000'],
['name':'200,000', 'id':'200,000'],
['name':'300,000', 'id':'300,000']
]}"
optionKey="id" optionValue="name"
/>
Of course when I post back to the server the value that gets sent is "100,000" as an escaped String. What I realised was that Grails, or Spring, or Hibernate, or something in the stack, would do the coersion of the String back into the right Integer type prior to persistence.
This works just fine for my purposes, however I think it is basically a work-round rather than a solution because of locale issues. If my thousand separator is a "." and my decimal separator is ",", which it is for much of Europe, then my code won't work.
Use like this :
<g:formatNumber number="${fieldValue(bean: personInstance, field: 'minPrice')}"
format="#.##"/>;