1 00:00:01,620 --> 00:00:04,630 All right, let's continue with our server side form validation. 2 00:00:04,650 --> 00:00:11,910 So right now we have this our reservation form, and that actually puts an empty form object in there 3 00:00:11,910 --> 00:00:13,950 that we can use for validation. 4 00:00:14,160 --> 00:00:21,360 And under our code, we under errors, we've defined a type of errors that will hold our errors, which 5 00:00:21,360 --> 00:00:26,910 is a map of type string with every value associated with an index of string being a slice of strings, 6 00:00:26,940 --> 00:00:30,510 because we might have more than one error for a given field in a form. 7 00:00:30,540 --> 00:00:31,610 That's why it's a slice. 8 00:00:32,310 --> 00:00:38,220 We have a function to add errors which will append an error and a message and associated with a particular 9 00:00:38,220 --> 00:00:38,670 field. 10 00:00:39,060 --> 00:00:43,980 And we have a function to check and see if there are errors and return the first error if there is one. 11 00:00:44,220 --> 00:00:47,070 OK, so that's for that part and other forms. 12 00:00:47,310 --> 00:00:54,090 We have our type that describes the form data that we're going to add errors to if any exist. 13 00:00:54,570 --> 00:00:58,710 And we have new, which allows us to create a new form, a new empty form. 14 00:00:59,380 --> 00:01:03,020 And we have this one check has which isn't finished yet. 15 00:01:03,030 --> 00:01:05,010 And you may have noticed that if you were paying attention. 16 00:01:05,490 --> 00:01:11,640 But let's go through the process of how we actually handle posted form data and perform server side 17 00:01:11,640 --> 00:01:12,260 validation. 18 00:01:12,780 --> 00:01:17,160 So I'm back in my handler's file and I'm looking at that empty function we created last time called 19 00:01:17,160 --> 00:01:18,020 Post Reservation. 20 00:01:18,390 --> 00:01:20,850 What's the very first thing I want to do? 21 00:01:21,060 --> 00:01:22,230 It is good practice. 22 00:01:22,230 --> 00:01:29,100 When you were parsing form data to do this, create a variable called error and assign it a method that's 23 00:01:29,100 --> 00:01:32,780 built on the request called pass form, and that's it. 24 00:01:33,150 --> 00:01:37,230 So you try to parse the form there and if there's an error, you take the user somewhere, you display 25 00:01:37,350 --> 00:01:38,040 whatever it may be. 26 00:01:38,040 --> 00:01:41,910 But all we're going to do right now is to say if error is not equal to nil. 27 00:01:42,030 --> 00:01:47,370 In other words, if there's an error parsing that form form data, then we'll just log it the print 28 00:01:47,370 --> 00:01:50,630 line, log the error and we'll return so they'll get a blank screen. 29 00:01:50,640 --> 00:01:55,590 I'm not going to see anything will make this better later on when we handle errors in a more sophisticated 30 00:01:55,590 --> 00:01:56,000 fashion. 31 00:01:56,940 --> 00:01:58,290 So I pass that form data. 32 00:01:58,680 --> 00:01:59,470 Now what do I do? 33 00:02:00,090 --> 00:02:04,530 Well, think about what we want to do here on my reservation page. 34 00:02:04,530 --> 00:02:09,210 I have four pieces of data, actually five one is the hidden form for the CSF token, but we're not 35 00:02:09,210 --> 00:02:10,200 doing anything with that. 36 00:02:10,200 --> 00:02:14,340 We're just letting our middleware make sure that this form is being posted from a page on our site. 37 00:02:14,610 --> 00:02:19,800 And it's not some malicious user who's written a script to access our forums as many times as he or 38 00:02:19,800 --> 00:02:22,160 she possibly can just because they're nasty. 39 00:02:22,170 --> 00:02:23,610 So we only have four we care about. 40 00:02:23,610 --> 00:02:24,450 We have first name. 41 00:02:24,840 --> 00:02:27,600 We have last name, we have email and we have phone. 42 00:02:27,750 --> 00:02:33,870 Now, I could if I wanted to back in my handler actually create four variables first name, last name, 43 00:02:33,870 --> 00:02:36,810 email and phone and keep track of all of those. 44 00:02:36,960 --> 00:02:38,550 But it's common practice. 45 00:02:38,550 --> 00:02:43,410 When I have data that's, you know, all associated with one another, let's create a new model. 46 00:02:43,410 --> 00:02:46,710 So I'm going to go to my models and I'm going to open. 47 00:02:47,380 --> 00:02:48,780 Let's see what shall I do. 48 00:02:50,250 --> 00:02:51,120 I just put it right here. 49 00:02:51,630 --> 00:02:52,140 Actually, no. 50 00:02:52,140 --> 00:02:57,240 Let's create a new file called Models New Go File, Model Start Go. 51 00:02:57,840 --> 00:03:00,270 Because the name of that one, I will add this. 52 00:03:00,630 --> 00:03:02,190 The name of that one is our template data. 53 00:03:02,220 --> 00:03:03,960 Here's where we're going to store all of our models. 54 00:03:03,960 --> 00:03:08,760 And eventually these models will be used to store things in a database to to get data from a database 55 00:03:08,760 --> 00:03:10,080 and store them in these models. 56 00:03:10,350 --> 00:03:16,860 But right now we're just going to create one and I'll create a model which I will call obviously reservation. 57 00:03:17,130 --> 00:03:26,370 So let's create a type of reservation, which is a struct, and it has one field for each of the kinds 58 00:03:26,370 --> 00:03:27,810 of information I need to store in that. 59 00:03:27,990 --> 00:03:34,470 So first name and I'm going to export it because I want it to be available outside of the models package. 60 00:03:34,650 --> 00:03:40,320 And it's a string and we'll have last name, email and phone, all of which are strings, last name, 61 00:03:41,640 --> 00:03:46,560 email and phone, and I'll give that a nice comment. 62 00:03:48,330 --> 00:03:53,340 Reservation holds the reservation data and I've created that type. 63 00:03:53,790 --> 00:04:00,690 So back in my handlers, let's open this up and let's actually store that data right in a reservation 64 00:04:00,690 --> 00:04:02,100 object, which we just created. 65 00:04:02,700 --> 00:04:09,660 So I'll create a reservation object like this reservation, which is just a variable name, and that's 66 00:04:09,660 --> 00:04:13,020 going to be a type models DOT reservation. 67 00:04:13,380 --> 00:04:18,060 And I'm actually going to populate it with the information that the user posted from the form, even 68 00:04:18,060 --> 00:04:20,090 though it might be bad data, I'm going to save it. 69 00:04:20,490 --> 00:04:27,120 So first name is going to be equal to and how do we get something from a post request are not formed 70 00:04:27,210 --> 00:04:27,540 yet. 71 00:04:27,540 --> 00:04:32,760 And the name that I want, which happens to be first name and then the last name 72 00:04:35,820 --> 00:04:45,270 which is assigned the value of our dot form dot get last name and one for email and for phone. 73 00:04:45,270 --> 00:04:46,230 So I'll just do it this way. 74 00:04:46,530 --> 00:04:51,000 Phone, email, phone 75 00:04:54,840 --> 00:04:55,480 and email. 76 00:04:58,260 --> 00:05:01,140 OK, so now I've populated this reservation. 77 00:05:01,350 --> 00:05:07,200 Variable as a struct of type models reservation, and I've given it all of the appropriate values, 78 00:05:07,710 --> 00:05:12,120 so I've grabbed first name from whatever they entered in the first name field of the form, last name, 79 00:05:12,120 --> 00:05:13,380 phone, email, same thing. 80 00:05:13,410 --> 00:05:14,550 That's all stored here. 81 00:05:14,550 --> 00:05:16,420 And this might be bad data. 82 00:05:17,340 --> 00:05:20,310 So how am I going to now check my form? 83 00:05:20,340 --> 00:05:24,560 Well, we don't have a form object at the moment, but we're going to get one. 84 00:05:24,600 --> 00:05:28,440 We're going to create a new one by creating forms our form, which is our variable. 85 00:05:28,860 --> 00:05:32,440 And we're going to assign that the value of forms new. 86 00:05:32,550 --> 00:05:37,100 And this time, we're not going to parse it until we're going to pass that post for our post four. 87 00:05:38,280 --> 00:05:42,130 So this is what has all those euro values and the associated data. 88 00:05:42,630 --> 00:05:46,530 So this is created by calling forms new right over here. 89 00:05:46,530 --> 00:05:48,780 And all that does is say, OK, get the data. 90 00:05:48,780 --> 00:05:54,750 You just passed me, which happened to be our post form, which is which is of type you are values and 91 00:05:55,200 --> 00:05:57,510 create the foreign object and send back a pointer to it. 92 00:05:57,520 --> 00:05:59,070 So we have that back at our handlers. 93 00:05:59,700 --> 00:06:01,230 We have our form now. 94 00:06:01,230 --> 00:06:02,290 We can actually check things. 95 00:06:02,460 --> 00:06:08,580 So the first thing we have over on forms Dargo is this has is the only thing we have that's not new 96 00:06:08,580 --> 00:06:13,490 or a typed definition we have this one function has and that returns bool. 97 00:06:13,620 --> 00:06:16,980 So let's go back here and you'll see why we don't have enough. 98 00:06:16,990 --> 00:06:20,250 Go back to our handlers and we want to make sure that it's valid. 99 00:06:20,250 --> 00:06:28,110 So I can just say on this form of that created form DOT has, it should have first name and I need to 100 00:06:28,110 --> 00:06:29,220 pass that my request. 101 00:06:29,670 --> 00:06:30,450 So there I've done that. 102 00:06:30,450 --> 00:06:37,560 I've now called form and said, hey, look, does this form have the value first name and is it something 103 00:06:37,560 --> 00:06:38,840 more than an empty string? 104 00:06:38,850 --> 00:06:43,280 We checked the form a post request for the value of first name. 105 00:06:43,290 --> 00:06:48,850 Does it have an entry for first name if it has one and its empty return false otherwise return true. 106 00:06:49,170 --> 00:06:55,500 So when I call this back over and handlers, I'm calling the function has, but I'm not doing anything 107 00:06:55,500 --> 00:06:59,880 with its response, so I probably should make this a little more valid. 108 00:07:00,330 --> 00:07:02,550 I need to check if my form is valid. 109 00:07:02,550 --> 00:07:05,400 It would be great if I could put whatever checks I want here. 110 00:07:05,400 --> 00:07:06,450 As many as I might have. 111 00:07:06,450 --> 00:07:13,470 I might have ten, I might have three and then just say, if not formed valid, do something. 112 00:07:13,560 --> 00:07:16,770 In other words, you failed form validation, but that function doesn't exist yet. 113 00:07:16,800 --> 00:07:17,760 So let's go put it in there. 114 00:07:17,760 --> 00:07:22,530 Let's go to our forms package and let's put in this func. 115 00:07:23,760 --> 00:07:29,610 And it's going to be having the receiver of a verb form so we can look at our form data of type form 116 00:07:31,200 --> 00:07:34,950 valid, and that's going to return a ball. 117 00:07:35,130 --> 00:07:36,360 So I better put my ball in there. 118 00:07:37,470 --> 00:07:42,570 All this, does it say if there are any errors at all associated with the form object F that I'm getting 119 00:07:42,570 --> 00:07:49,950 from my receiver return that the value of of fault, if there are errors and truth, are sorry. 120 00:07:50,130 --> 00:07:54,990 If it's valid, if there are no errors, return true or otherwise return false. 121 00:07:55,020 --> 00:08:03,610 So all I have to do here really is say return the length of errors if that happens to be equal to zero. 122 00:08:03,630 --> 00:08:04,380 It's going to return. 123 00:08:04,380 --> 00:08:04,770 True. 124 00:08:04,800 --> 00:08:06,540 Otherwise it's going to return false. 125 00:08:06,810 --> 00:08:08,730 That's a nice shorthand way of doing it. 126 00:08:08,760 --> 00:08:11,880 I could have written it over four lines and it would work just as well. 127 00:08:12,180 --> 00:08:14,880 But this seems to me to be the simplest approach to do it. 128 00:08:14,890 --> 00:08:15,690 So let's do this. 129 00:08:18,570 --> 00:08:20,490 Valid returns. 130 00:08:21,930 --> 00:08:26,370 True if there are no errors. 131 00:08:26,370 --> 00:08:29,250 In other words, the form is valid, otherwise false. 132 00:08:32,370 --> 00:08:34,310 OK, so that's great. 133 00:08:34,650 --> 00:08:40,020 But the other thing I need to pay attention to is my house check doesn't actually add an error anywhere. 134 00:08:40,020 --> 00:08:41,990 It just checks to see if the field exists. 135 00:08:42,210 --> 00:08:43,170 So we could do this. 136 00:08:43,650 --> 00:08:51,450 We can just go back to here before this return false part and say f dort errors, which is my receiver, 137 00:08:51,450 --> 00:08:56,310 I'm calling the F object and that has a function associated with it called ADD. 138 00:08:56,820 --> 00:09:02,460 And I can add my airstrip and the ad is for the field when I call it with first name that is populated 139 00:09:02,460 --> 00:09:03,870 with the string value of first name. 140 00:09:04,200 --> 00:09:10,080 And I don't need to specify the error message, which can be something as simple as this field cannot 141 00:09:10,080 --> 00:09:10,770 be blank. 142 00:09:11,730 --> 00:09:12,120 All right. 143 00:09:13,110 --> 00:09:16,950 So now when I call this, that actually will add an error to it. 144 00:09:16,950 --> 00:09:18,660 And that's exactly what I wanted to do. 145 00:09:19,860 --> 00:09:25,590 So we have our has we have our new and and our handlers now where you need to keep going. 146 00:09:25,600 --> 00:09:31,320 So if the form is not valid at this point, when I call form has now it's returning a false or true, 147 00:09:31,320 --> 00:09:37,020 which I'm ignoring, but it's also adding an error if first name is empty or nonexistent. 148 00:09:37,980 --> 00:09:46,160 So what I want to do, if the form is actually has a problem on it, well, pretty straightforward. 149 00:09:46,800 --> 00:09:50,940 Let's first of all, create a variable to hold our reservation. 150 00:09:50,940 --> 00:09:57,620 And when we're passing data to a template, remember, we had that value called data. 151 00:09:57,630 --> 00:10:01,790 So if we go over to our template data here, we have this nice one called Where Is It? 152 00:10:01,800 --> 00:10:04,050 Data, which is a map of string interface. 153 00:10:04,320 --> 00:10:07,220 So let's go back to our handlers and create a map of string interface. 154 00:10:07,800 --> 00:10:14,550 So I'll call it data is equal to make a map string interface. 155 00:10:15,990 --> 00:10:21,930 And then I'll add my reservation to that data reservation, which is how I'll look it up on the template 156 00:10:22,020 --> 00:10:23,790 when I need to, which I'm not going to do this lecture. 157 00:10:23,790 --> 00:10:29,710 But we will eventually is equal to the reservation, that object I created up here. 158 00:10:29,730 --> 00:10:31,880 So now I'm storing that in that value. 159 00:10:32,460 --> 00:10:34,380 And now what do I want to do? 160 00:10:34,380 --> 00:10:39,120 If they didn't pass validation, I can't just hand them back to the reservation handler because that's 161 00:10:39,120 --> 00:10:40,080 creating an empty form. 162 00:10:40,080 --> 00:10:42,300 But what I can do is the similar thing. 163 00:10:42,690 --> 00:10:44,850 I can actually render the form right from here. 164 00:10:45,390 --> 00:10:50,430 I can say render that form and I'm going to pass it, not forms new nil. 165 00:10:50,820 --> 00:10:56,040 I'm going to pass it form object I created here, which now has an error associated with it because 166 00:10:56,040 --> 00:11:02,220 I called the has function so I can just pass it forward, let me get rid of this and just put my variable 167 00:11:02,220 --> 00:11:02,700 form there. 168 00:11:02,790 --> 00:11:11,130 And I'm also going to pass it data which holds this reservation map or this map that has a value of 169 00:11:11,130 --> 00:11:11,960 reservation in it. 170 00:11:11,970 --> 00:11:14,550 So now I have the information that the user entered. 171 00:11:14,850 --> 00:11:19,680 I have the errors, if any, generated by this and I render that page. 172 00:11:19,800 --> 00:11:22,620 And at that point I want to stop processing this function. 173 00:11:22,620 --> 00:11:24,340 I don't want to go any further, so I'll just return. 174 00:11:25,440 --> 00:11:25,770 All right. 175 00:11:25,770 --> 00:11:26,820 Let's see what this does. 176 00:11:27,420 --> 00:11:29,220 So far, it's not going to do very much, but let's try it. 177 00:11:29,220 --> 00:11:32,790 Let's make sure it compiles or stop my application and rerun it. 178 00:11:34,830 --> 00:11:40,890 It comp. That's promising, let's go back over to our make reservation page, reload this and try submitting 179 00:11:40,890 --> 00:11:41,010 it. 180 00:11:42,390 --> 00:11:43,260 It took me back. 181 00:11:43,980 --> 00:11:45,170 It didn't do anything. 182 00:11:45,210 --> 00:11:45,780 Why not? 183 00:11:45,780 --> 00:11:48,210 Because I have no logic of my template to display errors. 184 00:11:48,990 --> 00:11:51,290 Well, we can do that if we can do it really easily. 185 00:11:51,300 --> 00:11:55,800 So let's go back over to open up our template, which is the make preservation page. 186 00:11:56,130 --> 00:12:02,790 Hide this window and let's think about how we can actually get access to the reservation object. 187 00:12:02,790 --> 00:12:03,810 Probably not this lecture. 188 00:12:03,820 --> 00:12:09,090 That'll be the next one, but get access to the errors object so we can do that pretty easily. 189 00:12:10,020 --> 00:12:12,380 What I'm going to do is write at the top here. 190 00:12:12,420 --> 00:12:14,460 I'm going to give myself a little bit of space to work. 191 00:12:15,120 --> 00:12:17,130 I'm only working with first name right now. 192 00:12:17,400 --> 00:12:22,440 And what I want to do is to say if there's an error, if there's an error associated with first name, 193 00:12:22,830 --> 00:12:25,740 I want to display something and I'm going to stick it right next to the label. 194 00:12:25,740 --> 00:12:28,980 So when there's an error, I want the error message to display right here. 195 00:12:29,410 --> 00:12:32,190 How am I going to get access to that errors object? 196 00:12:32,220 --> 00:12:38,430 Well, we know that we have a form object, so let's just use the new syntax you haven't seen it with. 197 00:12:38,700 --> 00:12:42,840 And that is a directive for a goal line template in the language, for the structure, for it is very 198 00:12:42,840 --> 00:12:51,870 simple with dot form dot errors, dot get and I'm going to look for the first name, the name of the 199 00:12:51,870 --> 00:12:55,890 field, and that's exactly how I'm storing it in that form object. 200 00:12:56,040 --> 00:13:03,510 I'm storing a string, a map of string, slice of strings and I'm saying with form errors get first 201 00:13:03,510 --> 00:13:09,120 name and this has to have an end like everything else, pretty much everything else and go like templates. 202 00:13:10,230 --> 00:13:16,200 I want to display something I don't want to display a label class equals text danger, which will make 203 00:13:16,200 --> 00:13:16,560 it red. 204 00:13:16,560 --> 00:13:17,760 That's a bootstrap class. 205 00:13:18,000 --> 00:13:24,450 And all I want to display is whatever the value from form errors get first name is. 206 00:13:24,990 --> 00:13:26,400 So I'll just display that. 207 00:13:26,550 --> 00:13:28,140 And that's all I have to do at this point. 208 00:13:28,410 --> 00:13:29,970 But I could do something else. 209 00:13:30,100 --> 00:13:30,840 It would be great. 210 00:13:30,840 --> 00:13:31,950 Let's just try it like this first. 211 00:13:31,950 --> 00:13:40,740 So let me stop the application and go back here, go to the Make Reservation page to make sure I'm starting 212 00:13:40,740 --> 00:13:45,510 with an empty form and click make reservation and it comes back to this form and gives me that error 213 00:13:45,510 --> 00:13:45,900 message. 214 00:13:46,410 --> 00:13:49,350 Be nice if I could make this be outlined in red as well. 215 00:13:49,380 --> 00:13:55,560 Well, it turns out I can't pretty easily and I can do that simply by in the class for the input which 216 00:13:55,560 --> 00:13:57,330 is right here. 217 00:13:57,570 --> 00:14:04,950 I can put more logic in there as well with DOT form, which is in our template data, part of our default 218 00:14:05,160 --> 00:14:07,440 default data and handed to us by the handler. 219 00:14:07,440 --> 00:14:13,740 When the form fails, validation errors don't get first name. 220 00:14:14,220 --> 00:14:19,830 So if that returns true, if there is more than one error, if there's a value stored informed, our 221 00:14:19,830 --> 00:14:23,850 errors don't get first name that map, string, slice of strings. 222 00:14:24,030 --> 00:14:24,930 What do I want to do? 223 00:14:25,050 --> 00:14:31,440 Well, all I want to do is add a class and the class is a bootstrap class called is invalid. 224 00:14:32,010 --> 00:14:33,660 And then of course I have to have my hand. 225 00:14:34,710 --> 00:14:39,660 Now if I do that and I'll put this down on the next line so it's organized a little better, I should 226 00:14:39,660 --> 00:14:45,540 be able to just run this because we're rebuilding our template cash in every request and it should make 227 00:14:45,810 --> 00:14:49,110 this box outlined in red and it failed. 228 00:14:49,260 --> 00:14:50,180 What did I get wrong? 229 00:14:50,190 --> 00:14:52,620 Let's go back here with format errors. 230 00:14:52,620 --> 00:14:56,820 Don't get first name is invalid and OK. 231 00:14:57,360 --> 00:14:58,170 Oh, there it is. 232 00:14:58,170 --> 00:14:58,320 Right. 233 00:14:58,320 --> 00:15:04,490 There is a quotation mark has to be on the outside, otherwise it's invalid html. 234 00:15:04,500 --> 00:15:10,350 So I have an opening class tag right here, but I never have a closing class tag or quote for that, 235 00:15:10,350 --> 00:15:14,130 so it never ends and go fortunately is extremely picky about that. 236 00:15:14,130 --> 00:15:16,630 So let's try this again now. 237 00:15:16,630 --> 00:15:18,720 It'll work and it does. 238 00:15:18,750 --> 00:15:23,460 It gives me the nice little thing right here, the little exclamation mark, it outlines this in red 239 00:15:23,460 --> 00:15:24,570 and it has an error message. 240 00:15:24,990 --> 00:15:25,320 All right. 241 00:15:25,320 --> 00:15:27,900 So that's how we can do some basic validation. 242 00:15:28,200 --> 00:15:30,240 But there are some problems associated with this. 243 00:15:30,240 --> 00:15:40,050 For example, I have for required fields and with my current approach back over here under my handlers 244 00:15:40,050 --> 00:15:43,800 right here, I would have to let me just hide this. 245 00:15:44,160 --> 00:15:49,320 I would have to do form has first name, form has last name, form has email. 246 00:15:49,500 --> 00:15:51,120 That seems really inefficient. 247 00:15:51,450 --> 00:15:56,400 It would be better if I could have, say, a different function or maybe modify this function something 248 00:15:56,400 --> 00:16:00,630 anyway where I could just pass it on any number of required fields. 249 00:16:00,900 --> 00:16:06,240 And if any of those fields are not required, it generates an error for that specific field. 250 00:16:07,050 --> 00:16:08,460 Well, there has to be a way to do that. 251 00:16:08,460 --> 00:16:10,740 And it turns out there is and we'll do that. 252 00:16:11,250 --> 00:16:15,180 And we'll also get around repopulating our form data with whatever they entered here. 253 00:16:15,180 --> 00:16:23,310 Because right now, if I put Smith and John at Smith DOT, CAA or whatever and and submit the form, 254 00:16:24,000 --> 00:16:28,710 I still lose that data, which seems kind of goofy because I've already got it stored in the reservation. 255 00:16:28,710 --> 00:16:30,330 There must be a better way of doing this. 256 00:16:30,330 --> 00:16:31,020 And in fact there is. 257 00:16:31,170 --> 00:16:33,180 And we'll take care of that in the next lecture.