What is the difference between <% %> and <%= %>? - asp-classic

I tried to find the difference on Google.
BUT
I 'm not able to search with '<% %>' , maybe the reason is <% is a HTML TAG
Now i'm thinking there's no diffrence betwwen <% and <%= .

<% %> executes the code between the 2 brackets.
<%= %> returns the value between the 2 brackets.
Example:
<% Response.Write("Hello.") %>
vs
<%= "Hello" %>

<% %> and <%= %> are normally server side scripts, the difference is first one does not print out the value to the page, unless you explicitly use print function, but second one will do automatically

Are you talking about the ASP ? If yes then <% %> is to hold the server side code and this is <%= %> equivalent to the Response.Write().

They're generally referred to as beestings. These particular ones are used by ASP.Net or ASP Classic. <% %> signifies server side code and <%=<Something%> is shorthand for <% Response.Write(<Something>) %>

If you want to show current date in a page you can do either of the following to write the date to the document. In the first sample using <% %> you have to explicitly use Response.Write.
<% Response.Write(DateTime.Now.ToString()) %>
and in the following one no need to explicitly write Response.Write
<%= DateTime.Now.ToString() %>

Related

How I take a link from my JSON data and make it into an image via Ruby on Rails?

<%= #schedule["data"][0]["visitorTeam"]["data"]["name"] %>
<%= #schedule["data"][0]["visitorTeam"]["data"]["logo_path"] %>
<%= #schedule["data"][0]["localTeam"]["data"]["name"] %>
<%= #schedule["data"][0]["localTeam"]["data"]["logo_path"] %>
Renders me
Rangers
https://cdn.sportmonks.com/images/soccer/teams/30/62.png
Celtic
https://cdn.sportmonks.com/images/soccer/teams/21/53.png
I'm creating a schedule page, so I'd like to set up the view so that it just goes to the same area of the respective JSON for each image. How do I make it so that it recognizes the link and turns it into an image every time it goes to "logo_path"?
I've tried something like
<%= image_tag <%= #schedule["data"][0]["localTeam"]["data"]["logo_path"] %> %>
but it didn't work for me. Any suggestions?
<%= image_tag #schedule["data"][0]["localTeam"]["data"]["logo_path"] %>
No need of an extra <%=.

Using article frontmatter when iterating in Middleman blog

Not the best title, but I'm honestly not sure on how to properly explain what I'm looking for help for.
So I'm using Middleman blog to well create my blog. Anyways, I'm using frontmatter to pass css that change the look of each page individually. I'm using 4 variables, link_color, text_color, bg_link. So what I want to do is reuse that same frontmatter information in the layout.html.erb file.
So the layout.html.erb is the standard
<% if paginate && num_pages > 1 %>
<p>Page <%= page_number %> of <%= num_pages %></p>
<% if prev_page %>
<p><%= link_to 'Previous page', prev_page %></p>
<% end %>
<% end %>
<% page_articles.each_with_index do |article, i| %>
<li class="article_summary">
<h1><%= link_to article.title, article, id: "#{i}" %></h1>
</li>
<% end %>
<% if paginate %>
<% if next_page %>
<p><%= link_to 'Next page', next_page %></p>
<% end %>
<% end %>
What I'm trying to do is for each article within that iterator is if the article has bg_color frontmatter then use that and change the color of the article.title if not, then do nothing. Currently if I try with something like:
<style>
<% if article.data.bg_color? %>
.article_summary a#<%= i %>{
color: rgb(<%=article.data.bg_color %>);
}
<% end %>
</style>
I'm doing it this way because my blog lives on Github.
Currently it works, but since it's just a simple iteration it gives every article that same color and not on a per article basis. So I'm trying to figure out the best way to utilize the index as some sort of id so that they're targeted individually.
Perhaps changing the li from a class to an id consisting of the index, but then I won't be able to apply a global style from the scss in the stylesheet folder no?
I've found a dirty method that works.
<% page_articles.each_with_index do |article, i| %>
<li class="article_summary" id="test_<%=i %>">
<h1><%= link_to article.title, article %></h1>
<style>
<% if article.data.bg_color? %>
#test_<%=i%> a{
color: <%=article.data.bg_color %>;
}
<% end %>
</style>
</li>
<% end %>
Pretty much added "test_" to the id (before I was just doing the index itself) and viola!

script tags in html

I'm having difficulties google what's the difference between the following script tags:
<%# ... %>
<% = ... %>
<% ... %>
Can someone help?
These tags also may be ASP.NET tags.
Here are links with the information about each tag:
<%# ... %> Data-Binding Expression Syntax
<%= ... %> Displaying from ASP.NET
<% ... %> Embedded Code Blocks in ASP.NET Web Pages
i don't know about the 1st one
but 2 and 3 was the jsp tag,
2 one is the expression tag like when you want to get value from jsp variable then you can use this tag
for e.g.
String arg = "Pratik"
now you want use this in jsp page anywhere
Hello <%= name %> ////// it will print on web page as Hello Pratik
the 3rd one is the script tag
when you want write block of jsp,java code you can write within this tag
for ex.
<%
String name="";
name = "abc";
out.println(name);
%>

Html helper extension works if I do <%= .. %> but not if I do <% Html.MyExt(); %>

Why does my html helper extension work if I do:
<%= Html.MyExt() %>
all mvc helpers work like:
<% Html.TextBox(""); %>
My extension builds a StringBuilder, then returns a string.
This helper must return string (ASP.NET MVC 1.0) or MvcHtmlString (ASP.NET MVC 2.0) which is written to the response stream (using Response.Write):
<%= Html.MyExt() %>
This helper returns nothing (void) it simply executes the extension method:
<% Html.TextBox(""); %>
<%= command %> runs the command and prints the returned string. The command must return a string.
<% command; %> just runs the command. Anything returned by the command will be ignored.
Most HTML helpers I've seen use the first format.

How can i call class from aspx file?

i have a class which is in App_Code/Kerbooo.cs i want to call that class's method from aspx file (not from code behind) is it possible? if it is, how can i do? thank you very much already now.
If the method is static, then the following should work within the aspx page:
<% Kerbooo.Method1(...) %>
If the method is not static, then you'll need an instance of Kerbooo:
<%
var kerbooo = new Kerbooo();
kerbooo.Method1(...)
%>
First, import the namespace that your code in App_Code uses:
<%# Import Namespace="MyNamespace" %>
If your code isn't in a namespace yet, it's a good idea to put it in one.
Next, you can call your code either with <% code; %> or <%= code %>, depending on whether you want to write the results to the output stream or not.
Data binding, as in <%# %>, requires a little extra work, as do expressions in <%$ %>
You can use <% %> and put your code in between (if you want to write stuff out <%= %> is a short cut for response.write but you need to do this outside of the <% %>
<%
var bob = new Kerbooo();
..do stuff with class
%>
you can mix and match (this does lead to spaghetti code so be carefull)
e.g looping
<table>
<%
var bob = new Kerbooo();
foreach(var thing in bob.GetThings())
{
%>
<tr><td><%=thing.StuffToWrite%><td></tr>
<%}%>
</table>
And your method should be public if your aspx does not inherit from a class in codebehind

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