.NET/ASP.NET/C#/VB.NET PDF Document SDK

The show action is simple, as all it does is retrieve a single entry from the database (using, as always, the find method provided by the Entry model from ActiveRecord::Base). You retrieve the ID from the URL through the params hash, a hash that is automatically populated by any data passed to the Rails application via the URL. If you use find with a single parameter containing an integer ID, then that row will be retrieved from the relevant table for the associated model, and returned as a single object. In this case, the entry retrieved is associated with @entry, then the view at app/views/entries/show.rhtml renders the page you see. Here are some examples of how some URLs relate to parameters that are found in the params hash:

winforms pdf 417 reader, winforms qr code reader, winforms upc-a reader, winforms data matrix reader, winforms gs1 128, winforms ean 13 reader, c# remove text from pdf, replace text in pdf c#, winforms code 39 reader, itextsharp remove text from pdf c#,

color to make it readable against the color you chose for the rectangle, right-click the title area, and change the Font color in this example, to white, as shown in Figure 8-9.

http://localhost/entries/show/1

If you want to catch more than one exception type with one block, you can specify them all in a tuple, as follows: try: x = input('Enter the first number: ') y = input('Enter the second number: ') print x/y except (ZeroDivisionError, TypeError): print 'Your numbers were bogus...' In the preceding code, if the user either enters a string or something other than a number, or if the second number is zero, the same error message is printed. Simply printing an error message isn t very helpful, of course. An alternative could be to keep asking for numbers until the division works. I show you how to do that in the section When All Is Well, later in this chapter.

params[:controller] == 'entries' params[:action] == 'show' params[:id] == '1'

Instead of inserting and designing new custom layouts, you can also rename and redesign the existing storyboard sketch layouts that you applied to your slides in 6. To do that, select and rename the Key Points Sketches custom layout to Key Point following the instructions in step 2 of the preceding procedure, and then make your design changes. When you have nished, return to Slide Sorter view, and you ll see that the layouts of the Key Point slides have been updated automatically according to the design changes you made.

params[:controller] == 'entries' params[:action] == 'another_method' params[:id] == '20' params[:formfield1] == 'test' params[:formfield2] == 'hello'

params[:controller] == 'test' params[:action] == 'test2' params[:formfield1] == 'test' params[:formfield2] == 'hello'

Note that the parentheses around the exceptions in the except clause are important; a common error is to omit them, in which case you may end up with something other than what you want. For an explanation, see the next section, Catching the Object.

Now that you have designed the Key Point custom layout, select a Key Point slide, and on the Home tab, in the Slides group, click Layout. The Of ce Theme window will now include the Key Point custom layout you created, as shown in Figure 8-10.

These examples demonstrate how you can pass data into methods within the URL (or, in the case of POST requests such as those that can be made from an HTML form within the HTTP request directly) and then access it by the controllers (or views) through the params hash. If you look at the code for the create action an action used to create the new entries as supplied by the form at http://localhost/entries/new you ll see how params is used to create new entries:

def create @entry = Entry.new(params[:entry]) if @entry.save flash[:notice] = 'Entry was successfully created.' redirect_to :action => 'list' else render :action => 'new' end end

In this method, you create a new entry with Entry.new(params[:entry]). The new method provided by ActiveRecord accepts the entire params hash and makes a new row of data from it. On the next line you save that row to the database using @entry.save, which returns true or false. If true (that is, the attempt is successful), the user will be redirected to the list action (try changing this to view_all). If the save isn t successful, the view for the new action is rendered using render :action => 'new'. Note how you can use redirect_to and render to perform operations that don t necessarily fit in with the usual controller action view life cycle, such as redirecting users elsewhere or rendering views associated with other controller actions.