WEBVTT 00:04.490 --> 00:10.850 Following on from the previous list and on redirect and rewrites engine X provides us with a third somewhat 00:10.850 --> 00:17.750 unique directive called Tri files try files as with the return and rewrite directives can be used in 00:17.750 --> 00:19.160 the server context. 00:19.280 --> 00:26.810 So applying to all incoming requests or inside a location context with trifles allows us to do is have 00:26.810 --> 00:33.860 engine X check for a resource to respond worth in any number of locations relative to the root directory 00:34.250 --> 00:38.900 with a final argument that result in a rewrite and re-evaluation. 00:38.900 --> 00:40.900 As with the rewrite directive. 00:41.180 --> 00:44.530 This is a directive which being so unique in its behaviour. 00:44.720 --> 00:50.600 I'd suggest you really try out in a number of ways using a simple test configuration but nonetheless 00:50.630 --> 00:53.360 will cover some arbitrary examples. 00:53.360 --> 00:59.570 First off are clear these rewrites from the previous lesson leave the Greek location as we can reuse 00:59.600 --> 00:59.830 that. 00:59.840 --> 01:06.320 In this lesson and also get rid of Greet slash John then in the server context. 01:06.320 --> 01:15.470 So applying to all incoming requests I'll say try files slash thumb Dot be in G first which we know 01:15.470 --> 01:16.490 exists. 01:16.670 --> 01:18.190 Followed by slash. 01:18.200 --> 01:19.010 Great. 01:19.310 --> 01:25.790 So what this directive is doing then all the time being in the server context is checking whether slash 01:25.820 --> 01:33.290 sites slash demo slash thumbed or PRNG exists and if it does serve it. 01:33.290 --> 01:39.300 If however this first argument doesn't exist move on and try the next one and so on. 01:39.320 --> 01:45.260 In our case some Thumper's PRNG definitely exists relative to the root directory so this should be served 01:45.260 --> 01:47.120 for all requests. 01:47.120 --> 01:50.150 Save this and reload the configuration. 01:50.150 --> 01:56.630 My browser has the demo side loaded at the moment so refresh and sure enough we get thumbed on PRNG. 01:56.900 --> 01:59.490 Try a u r l that doesn't exist at all. 01:59.570 --> 02:01.750 I'll say slash something. 02:02.470 --> 02:03.730 And the same. 02:03.970 --> 02:07.660 Or style C S S which does exist. 02:07.660 --> 02:09.300 No change. 02:09.310 --> 02:16.240 Try files intercept the requests checks if this first argument exists and serves it regardless of the 02:16.240 --> 02:16.690 request. 02:16.690 --> 02:22.580 You are I meaning that should we change some doppie energy to a resource that doesn't exist. 02:22.810 --> 02:30.460 Cat dog B and G drive files won't find it and move on to the next argument slash greet very important 02:30.460 --> 02:31.340 however when. 02:31.340 --> 02:33.920 Try files reaches its last argument. 02:34.000 --> 02:37.800 That argument is treated as an internal rewrite meaning. 02:37.810 --> 02:45.760 In this case and only in this case will the rewritten request also be re-evaluated and caught by this 02:45.820 --> 02:47.890 slash Greek location. 02:48.640 --> 02:53.050 Reload still on Style dotsie says Worth. 02:53.050 --> 02:53.760 Try files. 02:53.770 --> 02:57.360 No longer looking for thumb don't be in G reload. 02:57.550 --> 02:58.890 Hello user. 02:58.890 --> 03:05.830 That response from the Greek location as trifocals rewrote the request to slash greet and the same for 03:05.830 --> 03:06.180 the root. 03:06.190 --> 03:07.040 You are right. 03:08.170 --> 03:09.350 Typically then the. 03:09.360 --> 03:10.080 Try files. 03:10.080 --> 03:17.830 DirecTV is used with engine X variables for example to first check the request as it is we can add as 03:17.830 --> 03:19.450 the first argument here. 03:19.450 --> 03:20.440 The variable. 03:20.440 --> 03:21.400 You are right. 03:21.670 --> 03:23.520 Meaning before anything else. 03:23.530 --> 03:26.830 Try the you are I save and reload. 03:27.830 --> 03:30.300 This time try thumb dot P in G. 03:31.710 --> 03:32.420 And add loads. 03:32.460 --> 03:34.350 As it exists on the desk. 03:34.350 --> 03:36.580 Same for Style dotsie SS. 03:37.990 --> 03:40.070 And indexed old age to you Mel. 03:42.190 --> 03:49.060 Now knowing the last argument rewrites and is exactly that the last option this should ideally be something 03:49.060 --> 03:50.780 that won't ever fail. 03:50.800 --> 03:57.450 For example I'll create a new location to handle not found requests friendly underscore foro for. 03:58.180 --> 04:01.130 Which just returns a four of four worth. 04:01.150 --> 04:01.700 Sorry. 04:01.720 --> 04:03.670 That file could not be found. 04:05.760 --> 04:10.050 And use this location as the final argument on the trifocals directive. 04:10.900 --> 04:12.500 Save and reload. 04:14.210 --> 04:20.250 Make a request for a resource which doesn't exist for example slash nothing which will cause engine 04:20.260 --> 04:24.710 X to first look for the you are right as it is relative to the root. 04:24.950 --> 04:27.720 So slash sites slash demo slash. 04:27.740 --> 04:29.980 Nothing that doesn't exist. 04:29.990 --> 04:33.950 Meaning Go check for Slash sites slash demo slash cat. 04:33.970 --> 04:36.690 Don't be in G also doesn't exist. 04:36.800 --> 04:43.640 Then try slash greet which whilst we have a location for it still doesn't exist relative to the root 04:43.640 --> 04:44.680 directory. 04:44.750 --> 04:48.530 Remember only the very last argument causes a rewrite. 04:48.530 --> 04:54.440 These first ones only have engine X check relative to the root directory which means the slash nothing 04:54.440 --> 05:01.940 will finally be rewritten to slash friendly foro for revaluated and caught by the match and location 05:02.270 --> 05:04.930 resulting in this message and a foro for. 05:05.720 --> 05:06.470 Enter. 05:06.650 --> 05:09.220 And sure enough we get that message. 05:09.350 --> 05:13.660 We can confirm the status code using cool copy that you are real. 05:14.470 --> 05:15.190 Cool. 05:15.220 --> 05:15.840 Capital. 05:15.880 --> 05:16.620 I. 05:16.810 --> 05:19.190 And that request for a 4. 05:19.210 --> 05:20.130 Not Found. 05:20.980 --> 05:21.220 OK good. 05:21.220 --> 05:24.900 Very last thing I want to show in this lesson is named locations. 05:25.060 --> 05:31.030 This being a concept which you might run into at some point and name location simply means assigning 05:31.030 --> 05:35.850 a name to a location context and using a directive such as Try files. 05:35.950 --> 05:42.760 Use that location by its name ensuring no revaluation has to happen on that final argument but instead 05:42.760 --> 05:49.270 just a definite call to the name location to name a location then more specifically this friendly underscore 05:49.270 --> 05:57.790 foro for use an at sign with a name at friendly underscore foro for doing the same on the location in 05:57.790 --> 05:59.080 order to you name it. 05:59.660 --> 06:00.640 Reload. 06:02.400 --> 06:03.850 And the browser. 06:03.930 --> 06:09.500 We get the same back to some DOD PRNG it's found and served.