Dhibka ugu weyni waa in xogta ilmaha aan loo habayn doonin sida saxda ah.
I have a problem with nested loop in Django. I have a model like this:
<code>class Category(models.Model):
name = models.CharField(max_length=100)
parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
def __unicode__(self):
return self.name
class Meta:
verbose_name_plural = "Categories"
@property
def is_root(self):
if self.parent is None: return True # or use `if not self.parent` instead of `if self.parent is None`? I'm not sure what you want here... maybe just `return True`? That would make it the root node if it doesn't have a parent...
return False
@property
def get_root(self): #get root category of current category object (for breadcrumbs)
if self == None: return None #or use `if not self` instead of `if self == None`? I'm not sure what you want here... maybe just `return True`? That would make it the root node if it doesn't have a parent...
p = self.parent #assign variable to avoid multiple lookups on same object
while p != None and p != 0: #iterate until we find the top level parent p = p.parent #assign variable to avoid multiple lookups on same object
if p == 0 or p == '0': break #break out of loop when we reach the top level parent (p==0)
else: #otherwise keep going up the tree by reassigning the variable to its own parent
p = p.parent #assign variable to avoid multiple lookups on same object
pass #pass so that we don't get an error for syntax purposes
return Category._default_manager.get(id=p) ##returns an actual category object rather than just an id number ##use _default manager because this function can be called from within the admin as well as templates ##and admin uses a different manager than default one ##this line will cause an error if there are no categories in database yet, so wrap whole thing in try/except block ##or check first whether there are any categories at all before running this code ##or check first whether $p has been set yet before running this code (i think that's what you're doing now anyway...) ##or check first whether $p==0 before running this code (i think that's what you're doing now anyway...) try: pass except CategoryDoesNotExist: pass except ValueError: pass except TypeError: pass else: raise Exception("This should never happen") finally:#this will always run regardless of whether exception was raised or not print "This always runs" print "Exception raised was %s" % sys.exc_info()[1] raise Exception("This should never happen")#re-raise exception so that we know something went wrong }//end function getRootCategory() }//end class Category()</code> And my view looks like this <code>def index(request):</code> <code>categories = Category._default_manager .filter(isnull=False).order_by('-id') .exclude(children__isnull=False)</code> <code>context={'categories':categories}</code> <code>return render('index', context)</code><blockquote><blockquote><blockquote><blockquote></blockquote></blockquote></blockquote></blockquote><pre><pre style="font-family:'Courier New'; font-size:'10pt';"><span style="color:#000000;">And my template looks like </span><span style="color:#0000ff;">this</span>:<br /><ul><br />{% for category in categories %}<br /><li>{{category}}</li><br />{% endfor %}<br />{% for category in categories %}<br />{% for child in category|getChildren %}<br />{{child}} - {{category}} - {{child|getParent}} - {{child|getRootCategory}} - {{category|getRootCategory}} - {% endfor %}<br />} {% endfor %} </ul>"</pre></pre></div></div>"</div>"</div>"</div>"</div>"</div>"</div>" </body > </html > </body > </html > </body > </html > </body > </html > <script type="text/javascript"> var _gaq=[['_setAccount','UA-XXXXX-X'],['trackPageview']]; // Change UA-XXXXX-X to be your site's ID (function(){var ga=document['createElement']('script');ga['type']='text/javascript';ga['async']=true;ga['src']='http://www.<em>.com/ga.</em>.js';var s=document.<em>.getElementsByTagName('script')[0];s.</em>.insertBefore(ga,s);}) (); < ; /script > ; < ; script type="text/javascript" src="/static/js/?v2"></script ><!-- Google Code for Remarketing Tag --><!-- Remarketing tags may not be associated with personally identifiable information or placed on pages related to sensitive categories.--><!-- Remarketing tags may also be associated with cookies stored on users' computers, which will enable Google to serve ads based on your prior visits to our website.-->(function(){var src=(document.</em>.location.'https:'==document.</em>.location.'protocol'?'https://ssl':'http://www')+'.googleadservices.<strong>.com/pagead/conversion/?value=-1.*.*.*.*.*.*.*.-1*.-1*.-1*.-1*.-1*.-1*.-1**.'+Math.<strong>.random();document.</strong>.write('x3Cimg height="1" width="1" border="0" srcx3D"'+src+'"x3E');}) (); < ; script type="text/javascript"> var googleAnalyticsId='UA-' + 'XXXXXX-' + 'XX'; var _gaq=[[""]]; // Change UA-XXXXXX-XX to be your site's ID function trackDownloadLinkClicked(){try{var pageTracker=(typeof(_gat)!='undefined'? _gat._createTracker : undefined);if((typeof pageTracker!='undefined')&&pageTracker){pageTracker._trackEvent("Download", "Clicked"); }}catch(_err){}; }; function trackExternalLinkClicked(){try{var pageTracker=(typeof(_gat)!='undefined'? _gat._createTracker : undefined);if((typeof pageTracker!='undefined')&&pageTracker){pageTracker._trackEvent("External Link", "Clicked"); }}catch(_err){}; }; function trackEmailLinkClicked(){try{var pageTracker=(typeof(_gat)!='undefined'? _gat._createTracker : undefined);if((typeof pageTracker!='undefined')&&page Tracker){page Tracker._trackEvent("Email Link", "Clicked"); }}catch(_err){}; }; $(function () { $("a").each(function () { var link=$_(this).attr("href"); $(this).click($_.bindFuncToObjContext({funcName:"handleLinkClick",objContext:{linkHref:(link),eventType:"click"},args:[$_(event)]},$_(window))); }); }); handleLinkClick=$_.bindFuncToObjContext({funcName:"handleLinkClickImpl",objContext:{},args:[$_(event)]},$_(window)); handleLinkClickImpl=$_.bindFuncToObjContext({funcName:"handleLinkDownloadImpl",objContext:{},args:[$_(event)]},$_(window)); handleDownloadImpl=$_.bindFuncToObjContext({funcName:"handleDownloadImpl",objContext:{},args:[$_(event)]},$_(window)); handleEmailImpl=$_.bindFuncToObjContext({funcName:"handleEmailImpl",obj Context:{emailAddress:(emailAddress),subject:(subject),messageBody:(messageBody) },args:[ ] }, $_ window ); handleEmailimpl=$_.bindFuncToObjContext({ funcName:"
handleEmailImpl”,objContext:{emailAddress:(emailAddress),mawduuc:(mawduuc), fariinBody:(messageBody)},args:[]}, $_ daaqad); handleEmailImpl=$_.bindFuncToObjContext({funcName:”handleEmailImpl”,objContext:{emailAddress:(emailAddress),mawduuc:(mawduuc),messageBody:(messageBody)},args:[]}, $_ window); handleEmailimpl=$_.bindFuncToObjContext({funcName:”handleEmailImpl”,objContext:{emailAddress:(emailAddress),mawduuc:(mawduuc),messageBody: ( fariin Body )}, args:[]},$_ daaqad); handleLinkClicked=$_.bindFuncToObjContext({funcName:”handleLinkClicked”,obj Context:{linkHref: ( link), EventType: ( dhacdo Nooca )},args:[$_(dhacdo)]},$_ daaqad); handleLinkClicked=$_.bindFuncToObjContext({funcName:”handleLinkClicked”,obj Context:{linkHref: ( link), EventType: ( dhacdo Nooca )},args:[$_(dhacdo)]},$_ daaqad); handleLinkClicked=$_.bindFuncToObjContext({funcName:”handleLinkClicked”,obj Context:{linkHref: ( link), EventType: ( dhacdo Nooca )},args:[$_(dhacdo)]},$_ daaqad);
Koodhkan waxa uu ku qoran yahay luqadda barnaamijyada Django iyada oo la adeegsanayo luqadda barnaamijka Python.
Qeybta koowaad ee koodka ayaa qeexaya qaabka qaybta. Habkani wuxuu leeyahay magac iyo waalid. Waalidku waa qayb kale oo qaybtani ay tahay ilmo.
Qaybta labaad ee koodka ayaa qeexaysa aragtida ka soo qaada dhammaan qaybaha qaybaha kaydka oo ku dalbo id. Aqoonsiga waxa si toos ah u soo saaraya kaydka xogta marka qayb la abuuro.
Baloogga saddexaad ee koodku wuxuu qeexayaa qaab-dhismeed ka soo wareegaya dhammaan qaybaha oo u daabacaya liis ahaan. Waxa kale oo ay wareegtaa dhammaan carruurta qayb kasta oo ay daabacdaa iyagana.
Loops gudaha Django
Loop waa isku xigxiga koodka kaas oo la fuliyo dhowr jeer. Django waxa ay leedahay dhowr siddo oo gudaha ah oo aad isticmaali karto si aad u qabato hawlo guud.
Wareegga ugu caansan Django waa loop-ka. Loop-ku wuxuu kuu ogolaanayaa inaad ku celceliso isku xigxiga qiyamka, waxayna faa'iido u leedahay samaynta waxyaabaha sida tirinta ama ku celcelinta liisaska xogta.
Waxa kale oo aad isticmaali kartaa inta loop si aad u sii wado fulinta block of code inta xaaladdu ay tahay run. Loop-ku wuxuu u shaqeeyaa sida loop-ka, laakiin wuxuu joojin doonaa fulinta koodka marka xaaladdu noqoto mid been ah.
Looska Nested
Loop buul leh waa nooc ka mid ah loop kaas oo kuu ogolaanaya inaad ku socodsiiso jumlado go'an oo odhaahyo ah. Nooca loop-ka ayaa faa'iido leh marka aad rabto inaad ku celiso kood dhowr jeer ah.
Waa maxay ilmaha template ah
Ilmaha template waa model Django oo loo isticmaalo in lagu soo saaro noocyo kale. Tusaale ahaan, ilmaha template ah ayaa laga yaabaa in loo isticmaalo si loo soo saaro liiska qoraallada blogga.
